What is Neuroscience?

Introduction

Neuroscience (or neurobiology) is the scientific study of the nervous system. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developmental biology, cytology, mathematical modelling, and psychology to understand the fundamental and emergent properties of neurons and neural circuits. The understanding of the biological basis of learning, memory, behaviour, perception, and consciousness has been described by Eric Kandel as the “ultimate challenge” of the biological sciences.

The scope of neuroscience has broadened over time to include different approaches used to study the nervous system at different scales and the techniques used by neuroscientists have expanded enormously, from molecular and cellular studies of individual neurons to imaging of sensory, motor and cognitive tasks in the brain.

Brief History

The earliest study of the nervous system dates to ancient Egypt. Trepanation, the surgical practice of either drilling or scraping a hole into the skull for the purpose of curing head injuries or mental disorders, or relieving cranial pressure, was first recorded during the Neolithic period. Manuscripts dating to 1700 BC indicate that the Egyptians had some knowledge about symptoms of brain damage.

Early views on the function of the brain regarded it to be a “cranial stuffing” of sorts. In Egypt, from the late Middle Kingdom onwards, the brain was regularly removed in preparation for mummification. It was believed at the time that the heart was the seat of intelligence. According to Herodotus, the first step of mummification was to “take a crooked piece of iron, and with it draw out the brain through the nostrils, thus getting rid of a portion, while the skull is cleared of the rest by rinsing with drugs.”

The view that the heart was the source of consciousness was not challenged until the time of the Greek physician Hippocrates. He believed that the brain was not only involved with sensation – since most specialised organs (e.g. eyes, ears, tongue) are located in the head near the brain – but was also the seat of intelligence. Plato also speculated that the brain was the seat of the rational part of the soul. Aristotle, however, believed the heart was the centre of intelligence and that the brain regulated the amount of heat from the heart. This view was generally accepted until the Roman physician Galen, a follower of Hippocrates and physician to Roman gladiators, observed that his patients lost their mental faculties when they had sustained damage to their brains.

Abulcasis, Averroes, Avicenna, Avenzoar, and Maimonides, active in the Medieval Muslim world, described a number of medical problems related to the brain. In Renaissance Europe, Vesalius (1514-1564), René Descartes (1596-1650), Thomas Willis (1621-1675) and Jan Swammerdam (1637-1680) also made several contributions to neuroscience.

Luigi Galvani’s pioneering work in the late 1700s set the stage for studying the electrical excitability of muscles and neurons. In the first half of the 19th century, Jean Pierre Flourens pioneered the experimental method of carrying out localised lesions of the brain in living animals describing their effects on motricity, sensibility and behaviour. In 1843 Emil du Bois-Reymond demonstrated the electrical nature of the nerve signal, whose speed Hermann von Helmholtz proceeded to measure, and in 1875 Richard Caton found electrical phenomena in the cerebral hemispheres of rabbits and monkeys. Adolf Beck published in 1890 similar observations of spontaneous electrical activity of the brain of rabbits and dogs. Studies of the brain became more sophisticated after the invention of the microscope and the development of a staining procedure by Camillo Golgi during the late 1890s. The procedure used a silver chromate salt to reveal the intricate structures of individual neurons. His technique was used by Santiago Ramón y Cajal and led to the formation of the neuron doctrine, the hypothesis that the functional unit of the brain is the neuron. Golgi and Ramón y Cajal shared the Nobel Prize in Physiology or Medicine in 1906 for their extensive observations, descriptions, and categorizations of neurons throughout the brain.

In parallel with this research, work with brain-damaged patients by Paul Broca suggested that certain regions of the brain were responsible for certain functions. At the time, Broca’s findings were seen as a confirmation of Franz Joseph Gall’s theory that language was localised and that certain psychological functions were localised in specific areas of the cerebral cortex. The localisation of function hypothesis was supported by observations of epileptic patients conducted by John Hughlings Jackson, who correctly inferred the organisation of the motor cortex by watching the progression of seizures through the body. Carl Wernicke further developed the theory of the specialisation of specific brain structures in language comprehension and production. Modern research through neuroimaging techniques, still uses the Brodmann cerebral cytoarchitectonic map (referring to study of cell structure) anatomical definitions from this era in continuing to show that distinct areas of the cortex are activated in the execution of specific tasks.

During the 20th century, neuroscience began to be recognised as a distinct academic discipline in its own right, rather than as studies of the nervous system within other disciplines. Eric Kandel and collaborators have cited David Rioch, Francis O. Schmitt, and Stephen Kuffler as having played critical roles in establishing the field. Rioch originated the integration of basic anatomical and physiological research with clinical psychiatry at the Walter Reed Army Institute of Research, starting in the 1950s. During the same period, Schmitt established a neuroscience research programme within the Biology Department at the Massachusetts Institute of Technology, bringing together biology, chemistry, physics, and mathematics. The first freestanding neuroscience department (then called Psychobiology) was founded in 1964 at the University of California, Irvine by James L. McGaugh. This was followed by the Department of Neurobiology at Harvard Medical School, which was founded in 1966 by Stephen Kuffler.

The understanding of neurons and of nervous system function became increasingly precise and molecular during the 20th century. For example, in 1952, Alan Lloyd Hodgkin and Andrew Huxley presented a mathematical model for transmission of electrical signals in neurons of the giant axon of a squid, which they called “action potentials”, and how they are initiated and propagated, known as the Hodgkin-Huxley model. In 1961–1962, Richard FitzHugh and J. Nagumo simplified Hodgkin-Huxley, in what is called the FitzHugh-Nagumo model. In 1962, Bernard Katz modelled neurotransmission across the space between neurons known as synapses. Beginning in 1966, Eric Kandel and collaborators examined biochemical changes in neurons associated with learning and memory storage in Aplysia. In 1981 Catherine Morris and Harold Lecar combined these models in the Morris-Lecar model. Such increasingly quantitative work gave rise to numerous biological neuron models and models of neural computation.

As a result of the increasing interest about the nervous system, several prominent neuroscience organizations have been formed to provide a forum to all neuroscientist during the 20th century. For example, the International Brain Research Organisation was founded in 1961, the International Society for Neurochemistry in 1963, the European Brain and Behaviour Society in 1968, and the Society for Neuroscience in 1969. Recently, the application of neuroscience research results has also given rise to applied disciplines as neuroeconomics, neuroeducation, neuroethics, and neurolaw.

Over time, brain research has gone through philosophical, experimental, and theoretical phases, with work on brain simulation predicted to be important in the future.

Modern Neuroscience

The scientific study of the nervous system increased significantly during the second half of the twentieth century, principally due to advances in molecular biology, electrophysiology, and computational neuroscience. This has allowed neuroscientists to study the nervous system in all its aspects: how it is structured, how it works, how it develops, how it malfunctions, and how it can be changed.

For example, it has become possible to understand, in much detail, the complex processes occurring within a single neuron. Neurons are cells specialised for communication. They are able to communicate with neurons and other cell types through specialised junctions called synapses, at which electrical or electrochemical signals can be transmitted from one cell to another. Many neurons extrude a long thin filament of axoplasm called an axon, which may extend to distant parts of the body and are capable of rapidly carrying electrical signals, influencing the activity of other neurons, muscles, or glands at their termination points. A nervous system emerges from the assemblage of neurons that are connected to each other.

The vertebrate nervous system can be split into two parts: the central nervous system (defined as the brain and spinal cord), and the peripheral nervous system. In many species – including all vertebrates – the nervous system is the most complex organ system in the body, with most of the complexity residing in the brain. The human brain alone contains around one hundred billion neurons and one hundred trillion synapses; it consists of thousands of distinguishable substructures, connected to each other in synaptic networks whose intricacies have only begun to be unravelled. At least one out of three of the approximately 20,000 genes belonging to the human genome is expressed mainly in the brain.

Due to the high degree of plasticity of the human brain, the structure of its synapses and their resulting functions change throughout life.

Making sense of the nervous system’s dynamic complexity is a formidable research challenge. Ultimately, neuroscientists would like to understand every aspect of the nervous system, including how it works, how it develops, how it malfunctions, and how it can be altered or repaired. Analysis of the nervous system is therefore performed at multiple levels, ranging from the molecular and cellular levels to the systems and cognitive levels. The specific topics that form the main foci of research change over time, driven by an ever-expanding base of knowledge and the availability of increasingly sophisticated technical methods. Improvements in technology have been the primary drivers of progress. Developments in electron microscopy, computer science, electronics, functional neuroimaging, and genetics and genomics have all been major drivers of progress.

Molecular and Cellular Neuroscience

Basic questions addressed in molecular neuroscience include the mechanisms by which neurons express and respond to molecular signals and how axons form complex connectivity patterns. At this level, tools from molecular biology and genetics are used to understand how neurons develop and how genetic changes affect biological functions. The morphology, molecular identity, and physiological characteristics of neurons and how they relate to different types of behaviour are also of considerable interest.

Questions addressed in cellular neuroscience include the mechanisms of how neurons process signals physiologically and electrochemically. These questions include how signals are processed by neurites and somas and how neurotransmitters and electrical signals are used to process information in a neuron. Neurites are thin extensions from a neuronal cell body, consisting of dendrites (specialised to receive synaptic inputs from other neurons) and axons (specialised to conduct nerve impulses called action potentials). Somas are the cell bodies of the neurons and contain the nucleus.

Another major area of cellular neuroscience is the investigation of the development of the nervous system. Questions include the patterning and regionalisation of the nervous system, neural stem cells, differentiation of neurons and glia (neurogenesis and gliogenesis), neuronal migration, axonal and dendritic development, trophic interactions, and synapse formation.

Computational neurogenetic modelling is concerned with the development of dynamic neuronal models for modelling brain functions with respect to genes and dynamic interactions between genes.

Neural Circuits and Systems

Questions in systems neuroscience include how neural circuits are formed and used anatomically and physiologically to produce functions such as reflexes, multisensory integration, motor coordination, circadian rhythms, emotional responses, learning, and memory. In other words, they address how these neural circuits function in large-scale brain networks, and the mechanisms through which behaviours are generated. For example, systems level analysis addresses questions concerning specific sensory and motor modalities: how does vision work? How do songbirds learn new songs and bats localize with ultrasound? How does the somatosensory system process tactile information? The related fields of neuroethology and neuropsychology address the question of how neural substrates underlie specific animal and human behaviours. Neuroendocrinology and psychoneuroimmunology examine interactions between the nervous system and the endocrine and immune systems, respectively. Despite many advancements, the way that networks of neurons perform complex cognitive processes and behaviours is still poorly understood.

Cognitive and Behavioural Neuroscience

Cognitive neuroscience addresses the questions of how psychological functions are produced by neural circuitry. The emergence of powerful new measurement techniques such as neuroimaging (e.g. fMRI, PET, SPECT), EEG, MEG, electrophysiology, optogenetics and human genetic analysis combined with sophisticated experimental techniques from cognitive psychology allows neuroscientists and psychologists to address abstract questions such as how cognition and emotion are mapped to specific neural substrates. Although many studies still hold a reductionist stance looking for the neurobiological basis of cognitive phenomena, recent research shows that there is an interesting interplay between neuroscientific findings and conceptual research, soliciting and integrating both perspectives. For example, neuroscience research on empathy solicited an interesting interdisciplinary debate involving philosophy, psychology and psychopathology. Moreover, the neuroscientific identification of multiple memory systems related to different brain areas has challenged the idea of memory as a literal reproduction of the past, supporting a view of memory as a generative, constructive and dynamic process.

Neuroscience is also allied with the social and behavioural sciences as well as nascent interdisciplinary fields such as neuroeconomics, decision theory, social neuroscience, and neuromarketing to address complex questions about interactions of the brain with its environment. A study into consumer responses for example uses EEG to investigate neural correlates associated with narrative transportation into stories about energy efficiency.

Computational Neuroscience

Questions in computational neuroscience can span a wide range of levels of traditional analysis, such as development, structure, and cognitive functions of the brain. Research in this field utilises mathematical models, theoretical analysis, and computer simulation to describe and verify biologically plausible neurons and nervous systems. For example, biological neuron models are mathematical descriptions of spiking neurons which can be used to describe both the behaviour of single neurons as well as the dynamics of neural networks. Computational neuroscience is often referred to as theoretical neuroscience.

Nanoparticles in medicine are versatile in treating neurological disorders showing promising results in mediating drug transport across the blood brain barrier. Implementing nanoparticles in antiepileptic drugs enhances their medical efficacy by increasing bioavailability in the bloodstream, as well as offering a measure of control in release time concentration. Although nanoparticles can assist therapeutic drugs by adjusting physical properties to achieve desirable effects, inadvertent increases in toxicity often occur in preliminary drug trials. Furthermore, production of nanomedicine for drug trials is economically consuming, hindering progress in their implementation. Computational models in nanoneuroscience provide alternatives to study the efficacy of nanotechnology-based medicines in neurological disorders while mitigating potential side effects and development costs.

Nanomaterials often operate at length scales between classical and quantum regimes. Due to the associated uncertainties at the length scales that nanomaterials operate, it is difficult to predict their behaviour prior to in vivo studies. Classically, the physical processes which occur throughout neurons are analogous to electrical circuits. Designers focus on such analogies and model brain activity as a neural circuit. Success in computational modelling of neurons have led to the development of stereochemical models that accurately predict acetylcholine receptor-based synapses operating at microsecond time scales.

Ultrafine nanoneedles for cellular manipulations are thinner than the smallest single walled carbon nanotubes. Computational quantum chemistry is used to design ultrafine nanomaterials with highly symmetrical structures to optimise geometry, reactivity and stability.

Behaviour of nanomaterials are dominated by long ranged non-bonding interactions. Electrochemical processes that occur throughout the brain generate an electric field which can inadvertently affect the behaviour of some nanomaterials. Molecular dynamics simulations can mitigate the development phase of nanomaterials as well as prevent neural toxicity of nanomaterials following in vivo clinical trials. Testing nanomaterials using molecular dynamics optimizes nano characteristics for therapeutic purposes by testing different environment conditions, nanomaterial shape fabrications, nanomaterial surface properties, etc without the need for in vivo experimentation. Flexibility in molecular dynamic simulations allows medical practitioners to personalise treatment. Nanoparticle related data from translational nanoinformatics links neurological patient specific data to predict treatment response.

Nano-Neurotechnology

The visualization of neuronal activity is of key importance in the study of neurology. Nano-imaging tools with nanoscale resolution help in these areas. These optical imaging tools are PALM and STORM which helps visualise nanoscale objects within cells. Pampaloni states that, so far, these imaging tools revealed the dynamic behaviour and organisation of the actin cytoskeleton inside the cells, which will assist in understanding how neurons probe their involvement during neuronal outgrowth and in response to injury, and how they differentiate axonal processes and characterisation of receptor clustering and stoichiometry at the plasma inside the synapses, which are critical for understanding how synapses respond to changes in neuronal activity. These past works focused on devices for stimulation or inhibition of neural activity, but the crucial aspect is the ability for the device to simultaneously monitor neural activity. The major aspect that is to be improved in the nano imaging tools is the effective collection of the light as a major problem is that biological tissue are dispersive media that do not allow a straightforward propagation and control of light. These devices use nanoneedle and nanowire (NWs) for probing and stimulation.

NWs are artificial nano- or micro-sized “needles” that can provide high-fidelity electrophysiological recordings if used as microscopic electrodes for neuronal recordings. NWs are an attractive as they are highly functional structures that offer unique electronic properties that are affected by biological/chemical species adsorbed on their surface; mostly the conductivity. This conductivity variance depending on chemical species present allows enhanced sensing performances. NWs are also able to act as non-invasive and highly local probes. These versatility of NWs makes it optimal for interfacing with neurons due to the fact that the contact length along the axon (or the dendrite projection crossing a NW) is just about 20 nm.

Neuroscience and Medicine

Neurology, psychiatry, neurosurgery, psychosurgery, anesthesiology and pain medicine, neuropathology, neuroradiology, ophthalmology, otolaryngology, clinical neurophysiology, addiction medicine, and sleep medicine are some medical specialties that specifically address the diseases of the nervous system. These terms also refer to clinical disciplines involving diagnosis and treatment of these diseases.

Neurology works with diseases of the central and peripheral nervous systems, such as amyotrophic lateral sclerosis (ALS) and stroke, and their medical treatment. Psychiatry focuses on affective, behavioural, cognitive, and perceptual disorders. Anaesthesiology focuses on perception of pain, and pharmacologic alteration of consciousness. Neuropathology focuses upon the classification and underlying pathogenic mechanisms of central and peripheral nervous system and muscle diseases, with an emphasis on morphologic, microscopic, and chemically observable alterations. Neurosurgery and psychosurgery work primarily with surgical treatment of diseases of the central and peripheral nervous systems.

Translational Research

Recently, the boundaries between various specialties have blurred, as they are all influenced by basic research in neuroscience. For example, brain imaging enables objective biological insight into mental illnesses, which can lead to faster diagnosis, more accurate prognosis, and improved monitoring of patient progress over time.

Integrative neuroscience describes the effort to combine models and information from multiple levels of research to develop a coherent model of the nervous system. For example, brain imaging coupled with physiological numerical models and theories of fundamental mechanisms may shed light on psychiatric disorders.

Nanoneuroscience

One of the main goals of nanoneuroscience is to gain a detailed understanding of how the nervous system operates and, thus, how neurons organise themselves in the brain. Consequently, creating drugs and devices that are able to cross the blood brain barrier (BBB) are essential to allow for detailed imaging and diagnoses. The blood brain barrier functions as a highly specialised semipermeable membrane surrounding the brain, preventing harmful molecules that may be dissolved in the circulation blood from entering the central nervous system.

The main two hurdles for drug-delivering molecules to access the brain are size (must have a molecular weight < 400 Da) and lipid solubility. Physicians hope to circumvent difficulties in accessing the central nervous system through viral gene therapy. This often involves direct injection into the patient’s brain or cerebral spinal fluid. The drawback of this therapy is that it is invasive and carries a high risk factor due to the necessity of surgery for the treatment to be administered. Because of this, only 3.6% of clinical trials in this field have progressed to stage III since the concept of gene therapy was developed in the 1980s.

Another proposed way to cross the BBB is through temporary intentional disruption of the barrier. This method was first inspired by certain pathological conditions that were discovered to break down this barrier by themselves, such as Alzheimer’s disease, Parkinson’s disease, stroke, and seizure conditions.

Nanoparticles are unique from macromolecules because their surface properties are dependent on their size, allowing for strategic manipulation of these properties (or, “programming”) by scientists that would not be possible otherwise. Likewise, nanoparticle shape can also be varied to give a different set of characteristics based on the surface area to volume ratio of the particle.

Nanoparticles have promising therapeutic effects when treating neurodegenerative diseases. Oxygen reactive polymer (ORP) is a nano-platform programmed to react with oxygen and has been shown to detect and reduce the presence of reactive oxygen species (ROS) formed immediately after traumatic brain injuries. Nanoparticles have also been employed as a “neuroprotective” measure, as is the case with Alzheimer’s disease and stroke models. Alzheimer’s disease results in toxic aggregates of the amyloid beta protein formed in the brain. In one study, gold nanoparticles were programmed to attach themselves to these aggregates and were successful in breaking them up. Likewise, with ischemic stroke models, cells in the affected region of the brain undergo apoptosis, dramatically reducing blood flow to important parts of the brain and often resulting in death or severe mental and physical changes. Platinum nanoparticles have been shown to act as ROS, serving as “biological antioxidants” and significantly reducing oxidation in the brain as a result of stroke. Nanoparticles can also lead to neurotoxicity and cause permanent BBB damage either from brain oedema or from unrelated molecules crossing the BBB and causing brain damage. This proves further long term in vivo studies are needed to gain enough understanding to allow for successful clinical trials.

One of the most common nano-based drug delivery platforms is liposome-based delivery. They are both lipid-soluble and nano-scale and thus are permitted through a fully functioning BBB. Additionally, lipids themselves are biological molecules, making them highly biocompatible, which in turn lowers the risk of cell toxicity. The bilayer that is formed allows the molecule to fully encapsulate any drug, protecting it while it is travelling through the body. One drawback to shielding the drug from the outside cells is that it no longer has specificity, and requires coupling to extra antibodies to be able to target a biological site. Due to their low stability, liposome-based nanoparticles for drug delivery have a short shelf life.

Targeted therapy using magnetic nanoparticles (MNPs) is also a popular topic of research and has led to several stage III clinical trials. Invasiveness is not an issue here because a magnetic force can be applied from the outside of a patient’s body to interact and direct the MNPs. This strategy has been proven successful in delivering Brain-derived neurotropic factor, a naturally occurring gene thought to promote neurorehabilitation, across the BBB.

Major Branches

Modern neuroscience education and research activities can be very roughly categorised into the following major branches, based on the subject and scale of the system in examination as well as distinct experimental or curricular approaches. Individual neuroscientists, however, often work on questions that span several distinct subfields.

BranchDescription
Affective NeuroscienceAffective neuroscience is the study of the neural mechanisms involved in emotion, typically through experimentation on animal models.
Behavioural NeuroscienceBehavioural neuroscience (also known as biological psychology, physiological psychology, biopsychology, or psychobiology) is the application of the principles of biology to the study of genetic, physiological, and developmental mechanisms of behaviour in humans and non-human animals.
Cellular NeuroscienceCellular neuroscience is the study of neurons at a cellular level including morphology and physiological properties.
Clinical NeuroscienceThe scientific study of the biological mechanisms that underlie the disorders and diseases of the nervous system.
Cognitive NeuroscienceCognitive neuroscience is the study of the biological mechanisms underlying cognition.
Computational NeuroscienceComputational neuroscience is the theoretical study of the nervous system.
Cultural NeuroscienceCultural neuroscience is the study of how cultural values, practices and beliefs shape and are shaped by the mind, brain and genes across multiple timescales.
Developmental NeuroscienceDevelopmental neuroscience studies the processes that generate, shape, and reshape the nervous system and seeks to describe the cellular basis of neural development to address underlying mechanisms.
Evolutionary NeuroscienceEvolutionary neuroscience studies the evolution of nervous systems.
Molecular NeuroscienceMolecular neuroscience studies the nervous system with molecular biology, molecular genetics, protein chemistry, and related methodologies.
Neural NeuroscienceNeural engineering uses engineering techniques to interact with, understand, repair, replace, or enhance neural systems.
NeuroanatomyNeuroanatomy is the study of the anatomy of nervous systems.
NeurochemistryNeurochemistry is the study of how neurochemicals interact and influence the function of neurons.
NeuroethologyNeuroethology is the study of the neural basis of non-human animals behaviour.
NeurogastronomyNeurogastronomy is the study of flavour and how it affects sensation, cognition, and memory.
NeurogeneticsNeurogenetics is the study of the genetical basis of the development and function of the nervous system.
NeuroimagingNeuroimaging includes the use of various techniques to either directly or indirectly image the structure and function of the brain.
NeuroimmunologyNeuroimmunology is concerned with the interactions between the nervous and the immune system.
NeuroinformaticsNeuroinformatics is a discipline within bioinformatics that conducts the organisation of neuroscience data and application of computational models and analytical tools.
NeurolinguisticsNeurolinguistics is the study of the neural mechanisms in the human brain that control the comprehension, production, and acquisition of language.
NeurophysicsNeurophysics deals with the development of physical experimental tools to gain information about the brain.
NeurophysiologyNeurophysiology is the study of the functioning of the nervous system, generally using physiological techniques that include measurement and stimulation with electrodes or optically with ion- or voltage-sensitive dyes or light-sensitive channels.
NeuropsychologyNeuropsychology is a discipline that resides under the umbrellas of both psychology and neuroscience, and is involved in activities in the arenas of both basic science and applied science. In psychology, it is most closely associated with biopsychology, clinical psychology, cognitive psychology, and developmental psychology. In neuroscience, it is most closely associated with the cognitive, behavioural, social, and affective neuroscience areas. In the applied and medical domain, it is related to neurology and psychiatry.
PaleoneurobiologyPaleoneurobiology is a field which combines techniques used in palaeontology and archaeology to study brain evolution, especially that of the human brain.
Social NeuroscienceSocial neuroscience is an interdisciplinary field devoted to understanding how biological systems implement social processes and behaviour, and to using biological concepts and methods to inform and refine theories of social processes and behaviour.
Systems NeuroscienceSystems neuroscience is the study of the function of neural circuits and systems.

Neuroscience Organisations

The largest professional neuroscience organisation is the Society for Neuroscience (SFN), which is based in the United States but includes many members from other countries. Since its founding in 1969 the SFN has grown steadily: as of 2010 it recorded 40,290 members from 83 different countries. Annual meetings, held each year in a different American city, draw attendance from researchers, postdoctoral fellows, graduate students, and undergraduates, as well as educational institutions, funding agencies, publishers, and hundreds of businesses that supply products used in research.

Other major organisations devoted to neuroscience include the International Brain Research Organisation (IBRO), which holds its meetings in a country from a different part of the world each year, and the Federation of European Neuroscience Societies (FENS), which holds a meeting in a different European city every two years. FENS comprises a set of 32 national-level organisations, including the British Neuroscience Association, the German Neuroscience Society (Neurowissenschaftliche Gesellschaft), and the French Société des Neurosciences. The first National Honour Society in Neuroscience, Nu Rho Psi, was founded in 2006. Numerous youth neuroscience societies which support undergraduates, graduates and early career researchers also exist, like Project Encephalon.

In 2013, the BRAIN Initiative was announced in the US. An International Brain Initiative was created in 2017, currently integrated by more than seven national-level brain research initiatives (US, Europe, Allen Institute, Japan, China, Australia, Canada, Korea, Israel) spanning four continents.

Public Education and Outreach

In addition to conducting traditional research in laboratory settings, neuroscientists have also been involved in the promotion of awareness and knowledge about the nervous system among the general public and government officials. Such promotions have been done by both individual neuroscientists and large organisations. For example, individual neuroscientists have promoted neuroscience education among young students by organising the International Brain Bee, which is an academic competition for high school or secondary school students worldwide. In the United States, large organisations such as the Society for Neuroscience have promoted neuroscience education by developing a primer called Brain Facts, collaborating with public school teachers to develop Neuroscience Core Concepts for K-12 teachers and students, and cosponsoring a campaign with the Dana Foundation called Brain Awareness Week to increase public awareness about the progress and benefits of brain research. In Canada, the CIHR Canadian National Brain Bee is held annually at McMaster University.

Neuroscience educators formed Faculty for Undergraduate Neuroscience (FUN) in 1992 to share best practices and provide travel awards for undergraduates presenting at Society for Neuroscience meetings.

Finally, neuroscientists have also collaborated with other education experts to study and refine educational techniques to optimise learning among students, an emerging field called educational neuroscience. Federal agencies in the United States, such as the National Institute of Health (NIH) and National Science Foundation (NSF), have also funded research that pertains to best practices in teaching and learning of neuroscience concepts.

What is Emotion?

Introduction

Emotions are biological states associated with the nervous system brought on by neurophysiological changes variously associated with thoughts, feelings, behavioural responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. Emotions are often intertwined with mood, temperament, personality, disposition, creativity, and motivation.

Research on emotion has increased significantly over the past two decades with many fields contributing including psychology, neuroscience, affective neuroscience, endocrinology, medicine, history, sociology of emotions, and computer science. The numerous theories that attempt to explain the origin, neurobiology, experience, and function of emotions have only fostered more intense research on this topic. Current areas of research in the concept of emotion include the development of materials that stimulate and elicit emotion. In addition, positron emission tomography (PET) scans and functional magnetic resonance imaging (fMRI) scans help study the affective picture processes in the brain.

From a purely mechanistic perspective, emotions can be defined as “a positive or negative experience that is associated with a particular pattern of physiological activity.” Emotions produce different physiological, behavioural and cognitive changes. The original role of emotions was to motivate adaptive behaviours that in the past would have contributed to the passing on of genes through survival, reproduction, and kin selection.

In some theories, cognition is an important aspect of emotion. For those who act primarily on emotions, they may assume that they are not thinking, but mental processes involving cognition are still essential, particularly in the interpretation of events. For example, the realisation of our believing that we are in a dangerous situation and the subsequent arousal of our body’s nervous system (rapid heartbeat and breathing, sweating, muscle tension) is integral to the experience of our feeling afraid. Other theories, however, claim that emotion is separate from and can precede cognition. Consciously experiencing an emotion is exhibiting a mental representation of that emotion from a past or hypothetical experience, which is linked back to a content state of pleasure or displeasure. The content states are established by verbal explanations of experiences, describing an internal state.

Emotions are complex. According to some theories, they are states of feeling that result in physical and psychological changes that influence our behaviour. The physiology of emotion is closely linked to arousal of the nervous system with various states and strengths of arousal relating, apparently, to particular emotions. Emotion is also linked to behavioural tendency. Extroverted people are more likely to be social and express their emotions, while introverted people are more likely to be more socially withdrawn and conceal their emotions. Emotion is often the driving force behind motivation, positive or negative. According to other theories, emotions are not causal forces but simply syndromes of components, which might include motivation, feeling, behaviour, and physiological changes, but no one of these components is the emotion. Nor is the emotion an entity that causes these components.

Emotions involve different components, such as subjective experience, cognitive processes, expressive behaviour, psychophysiological changes, and instrumental behaviour. At one time, academics attempted to identify the emotion with one of the components: William James with a subjective experience, behaviourists with instrumental behaviour, psychophysiologists with physiological changes, and so on. More recently, emotion is said to consist of all the components. The different components of emotion are categorised somewhat differently depending on the academic discipline. In psychology and philosophy, emotion typically includes a subjective, conscious experience characterised primarily by psychophysiological expressions, biological reactions, and mental states. A similar multi-componential description of emotion is found in sociology. For example, Peggy Thoits described emotions as involving physiological components, cultural or emotional labels (anger, surprise, etc.), expressive body actions, and the appraisal of situations and contexts.

Brief History

Human nature and the following bodily sensations have been always part of the interest of thinkers and philosophers. Far most extensively, this interest has been of great interest by both Western and Eastern societies. Emotional states have been associated with the divine and the enlightenment of the human mind and body. The ever changing actions of individuals and its mood variations have been of great importance by most of the Western philosophers (Aristotle, Plato, Descartes, Aquinas, Hobbes) that lead them to propose vast theories; often competing theories, that sought to explain emotion and the following motivators of human action and its consequences.

In the Age of Enlightenment Scottish thinker David Hume proposed a revolutionary argument that sought to explain the main motivators of human action and conduct. He proposed that actions are motivated by “fears, desires, and passions”. As he wrote in his book Treatise of Human Nature (1773): “Reason alone can never be a motive to any action of the will… it can never oppose passion in the direction of the will… Reason is, and ought to be the slave of the passions, and can never pretend to any other office than to serve and obey them”. With these lines Hume pretended to explain that reason and further action will be subjected to the desires and experience of the self. Later thinkers would propose that actions and emotions are deeply interrelated to social, political, historical, and cultural aspects of reality that would be also associated with sophisticated neurological and physiological research on the brain and other parts of the physical body.

Etymology

The word “emotion” dates back to 1579, when it was adapted from the French word émouvoir, which means “to stir up”. The term emotion was introduced into academic discussion as a catch-all term to passions, sentiments and affections. The word “emotion” was coined in the early 1800s by Thomas Brown and it is around the 1830s that the modern concept of emotion first emerged for the English language. “No one felt emotions before about 1830. Instead they felt other things – “passions”, “accidents of the soul”, “moral sentiments” – and explained them very differently from how we understand emotions today.”

Some cross-cultural studies indicate that the categorisation of “emotion” and classification of basic emotions such as “anger” and “sadness” are not universal and that the boundaries and domains of these concepts are categorised differently by all cultures. However, others argue that there are some universal bases of emotions. In psychiatry and psychology, an inability to express or perceive emotion is sometimes referred to as alexithymia.

Definitions

The Oxford Dictionaries definition of emotion is “A strong feeling deriving from one’s circumstances, mood, or relationships with others.” Emotions are responses to significant internal and external events.

Emotions can be occurrences (e.g. panic) or dispositions (e.g. hostility), and short-lived (e.g. anger) or long-lived (e.g. grief). Psychotherapist Michael C. Graham describes all emotions as existing on a continuum of intensity. Thus fear might range from mild concern to terror or shame might range from simple embarrassment to toxic shame. Emotions have been described as consisting of a coordinated set of responses, which may include verbal, physiological, behavioural, and neural mechanisms.

Emotions have been categorised, with some relationships existing between emotions and some direct opposites existing. Graham differentiates emotions as functional or dysfunctional and argues all functional emotions have benefits.

In some uses of the word, emotions are intense feelings that are directed at someone or something. On the other hand, emotion can be used to refer to states that are mild (as in annoyed or content) and to states that are not directed at anything (as in anxiety and depression). One line of research looks at the meaning of the word emotion in everyday language and finds that this usage is rather different from that in academic discourse.

In practical terms, Joseph LeDoux has defined emotions as the result of a cognitive and conscious process which occurs in response to a body system response to a trigger.

Components

According to Scherer’s Component Process Model (CPM) of emotion, there are five crucial elements of emotion. From the component process perspective, emotional experience requires that all of these processes become coordinated and synchronised for a short period of time, driven by appraisal processes. Although the inclusion of cognitive appraisal as one of the elements is slightly controversial, since some theorists make the assumption that emotion and cognition are separate but interacting systems, the CPM provides a sequence of events that effectively describes the coordination involved during an emotional episode.

  • Cognitive appraisal: provides an evaluation of events and objects.
  • Bodily symptoms: the physiological component of emotional experience.
  • Action tendencies: a motivational component for the preparation and direction of motor responses.
  • Expression: facial and vocal expression almost always accompanies an emotional state to communicate reaction and intention of actions.
  • Feelings: the subjective experience of emotional state once it has occurred.

Differentiation

Emotion can be differentiated from a number of similar constructs within the field of affective neuroscience:

  • Feeling; not all feelings include emotion, such as the feeling of knowing. In the context of emotion, feelings are best understood as a subjective representation of emotions, private to the individual experiencing them.
  • Moods are diffuse affective states that generally last for much longer durations than emotions, are also usually less intense than emotions and often appear to lack a contextual stimulus.
  • Affect is used to describe the underlying affective experience of an emotion or a mood.

Purpose and Value

One view is that emotions facilitate adaptive responses to environmental challenges. Emotions have been described as a result of evolution because they provided good solutions to ancient and recurring problems that faced our ancestors. Emotions can function as a way to communicate what’s important to us, such as values and ethics. However some emotions, such as some forms of anxiety, are sometimes regarded as part of a mental illness and thus possibly of negative value.

Classification

A distinction can be made between emotional episodes and emotional dispositions. Emotional dispositions are also comparable to character traits, where someone may be said to be generally disposed to experience certain emotions. For example, an irritable person is generally disposed to feel irritation more easily or quickly than others do. Finally, some theorists place emotions within a more general category of “affective states” where affective states can also include emotion-related phenomena such as pleasure and pain, motivational states (for example, hunger or curiosity), moods, dispositions and traits.

Basic Emotions

For more than 40 years, Paul Ekman has supported the view that emotions are discrete, measurable, and physiologically distinct. Ekman’s most influential work revolved around the finding that certain emotions appeared to be universally recognised, even in cultures that were preliterate and could not have learned associations for facial expressions through media. Another classic study found that when participants contorted their facial muscles into distinct facial expressions (for example, disgust), they reported subjective and physiological experiences that matched the distinct facial expressions. Ekman’s facial-expression research examined six basic emotions: anger, disgust, fear, happiness, sadness and surprise. Later in his career, Ekman theorised that other universal emotions may exist beyond these six. In light of this, recent cross-cultural studies led by Daniel Cordaro and Dacher Keltner, both former students of Ekman, extended the list of universal emotions. In addition to the original six, these studies provided evidence for amusement, awe, contentment, desire, embarrassment, pain, relief, and sympathy in both facial and vocal expressions. They also found evidence for boredom, confusion, interest, pride, and shame facial expressions, as well as contempt, relief, and triumph vocal expressions.

Robert Plutchik agreed with Ekman’s biologically driven perspective but developed the “wheel of emotions”, suggesting eight primary emotions grouped on a positive or negative basis: joy versus sadness; anger versus fear; trust versus disgust; and surprise versus anticipation. Some basic emotions can be modified to form complex emotions. The complex emotions could arise from cultural conditioning or association combined with the basic emotions. Alternatively, similar to the way primary colours combine, primary emotions could blend to form the full spectrum of human emotional experience. For example, interpersonal anger and disgust could blend to form contempt. Relationships exist between basic emotions, resulting in positive or negative influences.

Multi-Dimensional Analysis

Psychologists have used methods such as factor analysis to attempt to map emotion-related responses onto a more limited number of dimensions. Such methods attempt to boil emotions down to underlying dimensions that capture the similarities and differences between experiences. Often, the first two dimensions uncovered by factor analysis are valence (how negative or positive the experience feels) and arousal (how energised or enervated the experience feels). These two dimensions can be depicted on a 2D coordinate map. This two-dimensional map has been theorised to capture one important component of emotion called core affect. Core affect is not theorised to be the only component to emotion, but to give the emotion its hedonic and felt energy.

Using statistical methods to analyse emotional states elicited by short videos, Cowen and Keltner identified 27 varieties of emotional experience: admiration, adoration, aesthetic appreciation, amusement, anger, anxiety, awe, awkwardness, boredom, calmness, confusion, craving, disgust, empathic pain, entrancement, excitement, fear, horror, interest, joy, nostalgia, relief, romance, sadness, satisfaction, sexual desire and surprise.

Theories

Pre-Modern History

In Buddhism, emotions occur when an object is considered as attractive or repulsive. There is a felt tendency impelling people towards attractive objects and impelling them to move away from repulsive or harmful objects; a disposition to possess the object (greed), to destroy it (hatred), to flee from it (fear), to get obsessed or worried over it (anxiety), and so on.

In stoic theories it was seen as a hindrance to reason and therefore a hindrance to virtue. Aristotle believed that emotions were an essential component of virtue. In the Aristotelian view all emotions (called passions) corresponded to appetites or capacities. During the Middle Ages, the Aristotelian view was adopted and further developed by scholasticism and Thomas Aquinas in particular.

In Chinese antiquity, excessive emotion was believed to cause damage to qi, which in turn, damages the vital organs. The four humours theory made popular by Hippocrates contributed to the study of emotion in the same way that it did for medicine.

In the early 11th century, Avicenna theorised about the influence of emotions on health and behaviours, suggesting the need to manage emotions.

Early modern views on emotion are developed in the works of philosophers such as René Descartes, Niccolò Machiavelli, Baruch Spinoza, Thomas Hobbes and David Hume. In the 19th century emotions were considered adaptive and were studied more frequently from an empiricist psychiatric perspective.

Western Theological

Christian perspective on emotion presupposes a theistic origin to humanity. God who created humans gave humans the ability to feel emotion and interact emotionally. Biblical content expresses that God is a person who feels and expresses emotion. Though a somatic view would place the locus of emotions in the physical body, Christian theory of emotions would view the body more as a platform for the sensing and expression of emotions. Therefore emotions themselves arise from the person, or that which is “imago-dei” or image of God in humans. In Christian thought, emotions have the potential to be controlled through reasoned reflection. That reasoned reflection also mimics God who made mind. The purpose of emotions in human life are therefore summarised in God’s call to enjoy Him and creation, humans are to enjoy emotions and benefit from them and use them to energise behaviour.

Evolutionary Theories (19th Century)

Perspectives on emotions from evolutionary theory were initiated during the mid-late 19th century with Charles Darwin’s 1872 book The Expression of the Emotions in Man and Animals. Surprisingly, Darwin argued that emotions served no evolved purpose for humans, neither in communication, nor in aiding survival. Darwin largely argued that emotions evolved via the inheritance of acquired characters. He pioneered various methods for studying non-verbal expressions, from which he concluded that some expressions had cross-cultural universality. Darwin also detailed homologous expressions of emotions that occur in animals. This led the way for animal research on emotions and the eventual determination of the neural underpinnings of emotion.

Evolutionary Theories (Contemporary)

More contemporary views along the evolutionary psychology spectrum posit that both basic emotions and social emotions evolved to motivate (social) behaviours that were adaptive in the ancestral environment. Emotion is an essential part of any human decision-making and planning, and the famous distinction made between reason and emotion is not as clear as it seems. Paul D. MacLean claims that emotion competes with even more instinctive responses, on one hand, and the more abstract reasoning, on the other hand. The increased potential in neuroimaging has also allowed investigation into evolutionarily ancient parts of the brain. Important neurological advances were derived from these perspectives in the 1990s by Joseph E. LeDoux and António Damásio.

Research on social emotion also focuses on the physical displays of emotion including body language of animals and humans (see affect display). For example, spite seems to work against the individual but it can establish an individual’s reputation as someone to be feared. Shame and pride can motivate behaviours that help one maintain one’s standing in a community, and self-esteem is one’s estimate of one’s status.

Somatic Theories (General)

Somatic theories of emotion claim that bodily responses, rather than cognitive interpretations, are essential to emotions. The first modern version of such theories came from William James in the 1880s. The theory lost favour in the 20th century, but has regained popularity more recently due largely to theorists such as John Cacioppo, António Damásio, Joseph E. LeDoux and Robert Zajonc who are able to appeal to neurological evidence.

Somatic Theories (James-Lange Theory)

In his 1884 article William James argued that feelings and emotions were secondary to physiological phenomena. In his theory, James proposed that the perception of what he called an “exciting fact” directly led to a physiological response, known as “emotion.” To account for different types of emotional experiences, James proposed that stimuli trigger activity in the autonomic nervous system, which in turn produces an emotional experience in the brain. The Danish psychologist Carl Lange also proposed a similar theory at around the same time, and therefore this theory became known as the James–Lange theory. As James wrote, “the perception of bodily changes, as they occur, is the emotion.” James further claims that “we feel sad because we cry, angry because we strike, afraid because we tremble, and either we cry, strike, or tremble because we are sorry, angry, or fearful, as the case may be.”

An example of this theory in action would be as follows: An emotion-evoking stimulus (snake) triggers a pattern of physiological response (increased heart rate, faster breathing, etc.), which is interpreted as a particular emotion (fear). This theory is supported by experiments in which by manipulating the bodily state induces a desired emotional state. Some people may believe that emotions give rise to emotion-specific actions, for example, “I’m crying because I’m sad,” or “I ran away because I was scared.” The issue with the James-Lange theory is that of causation (bodily states causing emotions and being a priori), not that of the bodily influences on emotional experience (which can be argued and is still quite prevalent today in biofeedback studies and embodiment theory).

Although mostly abandoned in its original form, Tim Dalgleish argues that most contemporary neuroscientists have embraced the components of the James-Lange theory of emotions.

The James-Lange theory has remained influential. Its main contribution is the emphasis it places on the embodiment of emotions, especially the argument that changes in the bodily concomitants of emotions can alter their experienced intensity. Most contemporary neuroscientists would endorse a modified James-Lange view in which bodily feedback modulates the experience of emotion.

Somatic Theories (Cannon-Bard Theory)

Walter Bradford Cannon agreed that physiological responses played a crucial role in emotions, but did not believe that physiological responses alone could explain subjective emotional experiences. He argued that physiological responses were too slow and often imperceptible and this could not account for the relatively rapid and intense subjective awareness of emotion. He also believed that the richness, variety, and temporal course of emotional experiences could not stem from physiological reactions, that reflected fairly undifferentiated fight or flight responses. An example of this theory in action is as follows: An emotion-evoking event (snake) triggers simultaneously both a physiological response and a conscious experience of an emotion.

Phillip Bard contributed to the theory with his work on animals. Bard found that sensory, motor, and physiological information all had to pass through the diencephalon (particularly the thalamus), before being subjected to any further processing. Therefore, Cannon also argued that it was not anatomically possible for sensory events to trigger a physiological response prior to triggering conscious awareness and emotional stimuli had to trigger both physiological and experiential aspects of emotion simultaneously.

Somatic Theories (Two-Factor Theory)

Stanley Schachter formulated his theory on the earlier work of a Spanish physician, Gregorio Marañón, who injected patients with epinephrine and subsequently asked them how they felt. Marañón found that most of these patients felt something but in the absence of an actual emotion-evoking stimulus, the patients were unable to interpret their physiological arousal as an experienced emotion. Schachter did agree that physiological reactions played a big role in emotions. He suggested that physiological reactions contributed to emotional experience by facilitating a focused cognitive appraisal of a given physiologically arousing event and that this appraisal was what defined the subjective emotional experience. Emotions were thus a result of two-stage process:

  1. General physiological arousal; and
  2. Experience of emotion.

For example, the physiological arousal, heart pounding, in a response to an evoking stimulus, the sight of a bear in the kitchen. The brain then quickly scans the area, to explain the pounding, and notices the bear. Consequently, the brain interprets the pounding heart as being the result of fearing the bear. With his student, Jerome Singer, Schachter demonstrated that subjects can have different emotional reactions despite being placed into the same physiological state with an injection of epinephrine. Subjects were observed to express either anger or amusement depending on whether another person in the situation (a confederate) displayed that emotion. Hence, the combination of the appraisal of the situation (cognitive) and the participants’ reception of adrenaline or a placebo together determined the response. This experiment has been criticised in Jesse Prinz’s (2004) Gut Reactions.

Cognitive Theories (General)

With the two-factor theory now incorporating cognition, several theories began to argue that cognitive activity in the form of judgments, evaluations, or thoughts were entirely necessary for an emotion to occur. One of the main proponents of this view was Richard Lazarus who argued that emotions must have some cognitive intentionality. The cognitive activity involved in the interpretation of an emotional context may be conscious or unconscious and may or may not take the form of conceptual processing.

Lazarus’ theory is very influential; emotion is a disturbance that occurs in the following order:

  • Cognitive appraisal: The individual assesses the event cognitively, which cues the emotion.
  • Physiological changes: The cognitive reaction starts biological changes such as increased heart rate or pituitary adrenal response.
  • Action: The individual feels the emotion and chooses how to react.

For example: Jenny sees a snake.

  • Jenny cognitively assesses the snake in her presence and cognition allows her to understand it as a danger.
  • Her brain activates the adrenal glands which pump adrenaline through her blood stream, resulting in increased heartbeat.
  • Jenny screams and runs away.

Lazarus stressed that the quality and intensity of emotions are controlled through cognitive processes. These processes underline coping strategies that form the emotional reaction by altering the relationship between the person and the environment.

George Mandler provided an extensive theoretical and empirical discussion of emotion as influenced by cognition, consciousness, and the autonomic nervous system in two books (Mind and Emotion, 1975, and Mind and Body: Psychology of Emotion and Stress, 1984)

There are some theories on emotions arguing that cognitive activity in the form of judgments, evaluations, or thoughts are necessary in order for an emotion to occur. A prominent philosophical exponent is Robert C. Solomon (for example, The Passions, Emotions and the Meaning of Life, 1993). Solomon claims that emotions are judgments. He has put forward a more nuanced view which responds to what he has called the ‘standard objection’ to cognitivism, the idea that a judgment that something is fearsome can occur with or without emotion, so judgment cannot be identified with emotion. The theory proposed by Nico Frijda where appraisal leads to action tendencies is another example.

It has also been suggested that emotions (affect heuristics, feelings and gut-feeling reactions) are often used as shortcuts to process information and influence behaviour. The affect infusion model (AIM) is a theoretical model developed by Joseph Forgas in the early 1990s that attempts to explain how emotion and mood interact with one’s ability to process information.

Cognitive Theories (Perceptual Theory)

Theories dealing with perception either use one or multiples perceptions in order to find an emotion. A recent hybrid of the somatic and cognitive theories of emotion is the perceptual theory. This theory is neo-Jamesian in arguing that bodily responses are central to emotions, yet it emphasizes the meaningfulness of emotions or the idea that emotions are about something, as is recognised by cognitive theories. The novel claim of this theory is that conceptually-based cognition is unnecessary for such meaning. Rather the bodily changes themselves perceive the meaningful content of the emotion because of being causally triggered by certain situations. In this respect, emotions are held to be analogous to faculties such as vision or touch, which provide information about the relation between the subject and the world in various ways. A sophisticated defence of this view is found in philosopher Jesse Prinz’s book Gut Reactions, and psychologist James Laird’s book Feelings.

Cognitive Theories (Affective Events Theory)

Affective events theory is a communication-based theory developed by Howard M. Weiss and Russell Cropanzano (1996), that looks at the causes, structures, and consequences of emotional experience (especially in work contexts). This theory suggests that emotions are influenced and caused by events which in turn influence attitudes and behaviours. This theoretical frame also emphasizes time in that human beings experience what they call emotion episodes – a “series of emotional states extended over time and organized around an underlying theme.” This theory has been utilised by numerous researchers to better understand emotion from a communicative lens, and was reviewed further by Howard M. Weiss and Daniel J. Beal in their article, “Reflections on Affective Events Theory”, published in Research on Emotion in Organisations in 2005.

Situated Perspective on Emotion

A situated perspective on emotion, developed by Paul E. Griffiths and Andrea Scarantino, emphasizes the importance of external factors in the development and communication of emotion, drawing upon the situationism approach in psychology. This theory is markedly different from both cognitivist and neo-Jamesian theories of emotion, both of which see emotion as a purely internal process, with the environment only acting as a stimulus to the emotion. In contrast, a situationist perspective on emotion views emotion as the product of an organism investigating its environment, and observing the responses of other organisms. Emotion stimulates the evolution of social relationships, acting as a signal to mediate the behaviour of other organisms. In some contexts, the expression of emotion (both voluntary and involuntary) could be seen as strategic moves in the transactions between different organisms. The situated perspective on emotion states that conceptual thought is not an inherent part of emotion, since emotion is an action-oriented form of skilful engagement with the world. Griffiths and Scarantino suggested that this perspective on emotion could be helpful in understanding phobias, as well as the emotions of infants and animals.

Genetics

Emotions can motivate social interactions and relationships and therefore are directly related with basic physiology, particularly with the stress systems. This is important because emotions are related to the anti-stress complex, with an oxytocin-attachment system, which plays a major role in bonding. Emotional phenotype temperaments affect social connectedness and fitness in complex social systems. These characteristics are shared with other species and taxa and are due to the effects of genes and their continuous transmission. Information that is encoded in the DNA sequences provides the blueprint for assembling proteins that make up our cells. Zygotes require genetic information from their parental germ cells, and at every speciation event, heritable traits that have enabled its ancestor to survive and reproduce successfully are passed down along with new traits that could be potentially beneficial to the offspring.

In the five million years since the lineages leading to modern humans and chimpanzees split, only about 1.2% of their genetic material has been modified. This suggests that everything that separates us from chimpanzees must be encoded in that very small amount of DNA, including our behaviours. Students that study animal behaviours have only identified intraspecific examples of gene-dependent behavioural phenotypes. In voles (Microtus spp.) minor genetic differences have been identified in a vasopressin receptor gene that corresponds to major species differences in social organisation and the mating system. Another potential example with behavioural differences is the FOCP2 gene, which is involved in neural circuitry handling speech and language. Its present form in humans differed from that of the chimpanzees by only a few mutations and has been present for about 200,000 years, coinciding with the beginning of modern humans. Speech, language, and social organization are all part of the basis for emotions.

Formation

Neurobiological Explanation

Based on discoveries made through neural mapping of the limbic system, the neurobiological explanation of human emotion is that emotion is a pleasant or unpleasant mental state organized in the limbic system of the mammalian brain. If distinguished from reactive responses of reptiles, emotions would then be mammalian elaborations of general vertebrate arousal patterns, in which neurochemicals (for example, dopamine, noradrenaline, and serotonin) step-up or step-down the brain’s activity level, as visible in body movements, gestures and postures. Emotions can likely be mediated by pheromones (think fear).

For example, the emotion of love is proposed to be the expression of Paleocircuits of the mammalian brain (specifically, modules of the cingulate gyrus) which facilitate the care, feeding, and grooming of offspring. Paleocircuits are neural platforms for bodily expression configured before the advent of cortical circuits for speech. They consist of pre-configured pathways or networks of nerve cells in the forebrain, brain stem and spinal cord.

Other emotions like fear and anxiety long thought to be exclusively generated by the most primitive parts of the brain (stem) and more associated to the fight-or-flight responses of behaviour, have also been associated as adaptive expressions of defensive behaviour whenever a threat is encountered. Although defensive behaviours have been present in a wide variety of species, Blanchard et al. (2001) discovered a correlation of given stimuli and situation that resulted in a similar pattern of defensive behaviour towards a threat in human and non-human mammals.

Whenever, potentially dangerous stimuli is presented additional brain structures activate that previously thought (hippocampus, thalamus, etc). Thus, giving the amygdala an important role on coordinating the following behavioural input based on the presented neurotransmitters that respond to threat stimuli. These biological functions of the amygdala are not only limited to the “fear-conditioning” and “processing of aversive stimuli”, but also are present on other components of the amygdala. Therefore, it can referred the amygdala as a key structure to understand the potential responses of behaviour in danger like situations in human and non-human mammals.

The motor centres of reptiles react to sensory cues of vision, sound, touch, chemical, gravity, and motion with pre-set body movements and programmed postures. With the arrival of night-active mammals, smell replaced vision as the dominant sense, and a different way of responding arose from the olfactory sense, which is proposed to have developed into mammalian emotion and emotional memory. The mammalian brain invested heavily in olfaction to succeed at night as reptiles slept – one explanation for why olfactory lobes in mammalian brains are proportionally larger than in the reptiles. These odour pathways gradually formed the neural blueprint for what was later to become our limbic brain.

Emotions are thought to be related to certain activities in brain areas that direct our attention, motivate our behaviour, and determine the significance of what is going on around us. Pioneering work by Paul Broca (1878), James Papez (1937), and Paul D. MacLean (1952) suggested that emotion is related to a group of structures in the centre of the brain called the limbic system, which includes the hypothalamus, cingulate cortex, hippocampi, and other structures. More recent research has shown that some of these limbic structures are not as directly related to emotion as others are while some non-limbic structures have been found to be of greater emotional relevance.

Prefrontal Cortex

There is ample evidence that the left prefrontal cortex is activated by stimuli that cause positive approach. If attractive stimuli can selectively activate a region of the brain, then logically the converse should hold, that selective activation of that region of the brain should cause a stimulus to be judged more positively. This was demonstrated for moderately attractive visual stimuli and replicated and extended to include negative stimuli.

Two neurobiological models of emotion in the prefrontal cortex made opposing predictions. The valence model predicted that anger, a negative emotion, would activate the right prefrontal cortex. The direction model predicted that anger, an approach emotion, would activate the left prefrontal cortex. The second model was supported.

This still left open the question of whether the opposite of approach in the prefrontal cortex is better described as moving away (direction model), as unmoving but with strength and resistance (movement model), or as unmoving with passive yielding (action tendency model). Support for the action tendency model (passivity related to right prefrontal activity) comes from research on shyness and research on behavioural inhibition. Research that tested the competing hypotheses generated by all four models also supported the action tendency model.

Homeostatic/Primordial Emotion

Another neurological approach proposed by Bud Craig in 2003 distinguishes two classes of emotion: “classical” emotions such as love, anger and fear that are evoked by environmental stimuli, and “homeostatic emotions” – attention-demanding feelings evoked by body states, such as pain, hunger and fatigue, that motivate behaviour (withdrawal, eating or resting in these examples) aimed at maintaining the body’s internal milieu at its ideal state.

Derek Denton calls the latter “primordial emotions” and defines them as “the subjective element of the instincts, which are the genetically programmed behaviour patterns which contrive homeostasis. They include thirst, hunger for air, hunger for food, pain and hunger for specific minerals etc. There are two constituents of a primordial emotion – the specific sensation which when severe may be imperious, and the compelling intention for gratification by a consummatory act.”

Emergent Explanation

Joseph LeDoux differentiates between the human’s defence system, which has evolved over time, and emotions such as fear and anxiety. He has said that the amygdala may release hormones due to a trigger (such as an innate reaction to seeing a snake), but “then we elaborate it through cognitive and conscious processes”.

Lisa Feldman Barrett highlights differences in emotions between different cultures, and says that emotions (such as anxiety) “are not triggered; you create them. They emerge as a combination of the physical properties of your body, a flexible brain that wires itself to whatever environment it develops in, and your culture and upbringing, which provide that environment.” She has termed this approach the theory of constructed emotion.

Disciplinary Approaches

Many different disciplines have produced work on the emotions. Human sciences study the role of emotions in mental processes, disorders, and neural mechanisms. In psychiatry, emotions are examined as part of the discipline’s study and treatment of mental disorders in humans. Nursing studies emotions as part of its approach to the provision of holistic health care to humans. Psychology examines emotions from a scientific perspective by treating them as mental processes and behaviour and they explore the underlying physiological and neurological processes. In neuroscience sub-fields such as social neuroscience and affective neuroscience, scientists study the neural mechanisms of emotion by combining neuroscience with the psychological study of personality, emotion, and mood. In linguistics, the expression of emotion may change to the meaning of sounds. In education, the role of emotions in relation to learning is examined.

Social sciences often examine emotion for the role that it plays in human culture and social interactions. In sociology, emotions are examined for the role they play in human society, social patterns and interactions, and culture. In anthropology, the study of humanity, scholars use ethnography to undertake contextual analyses and cross-cultural comparisons of a range of human activities. Some anthropology studies examine the role of emotions in human activities. In the field of communication sciences, critical organisational scholars have examined the role of emotions in organisations, from the perspectives of managers, employees, and even customers. A focus on emotions in organisations can be credited to Arlie Russell Hochschild’s concept of emotional labour. The University of Queensland hosts EmoNet, an e-mail distribution list representing a network of academics that facilitates scholarly discussion of all matters relating to the study of emotion in organisational settings. The list was established in January 1997 and has over 700 members from across the globe.

In economics, the social science that studies the production, distribution, and consumption of goods and services, emotions are analysed in some sub-fields of microeconomics, in order to assess the role of emotions on purchase decision-making and risk perception. In criminology, a social science approach to the study of crime, scholars often draw on behavioural sciences, sociology, and psychology; emotions are examined in criminology issues such as anomie theory and studies of “toughness,” aggressive behaviour, and hooliganism. In law, which underpins civil obedience, politics, economics and society, evidence about people’s emotions is often raised in tort law claims for compensation and in criminal law prosecutions against alleged lawbreakers (as evidence of the defendant’s state of mind during trials, sentencing, and parole hearings). In political science, emotions are examined in a number of sub-fields, such as the analysis of voter decision-making.

In philosophy, emotions are studied in sub-fields such as ethics, the philosophy of art (for example, sensory – emotional values, and matters of taste and sentimentality), and the philosophy of music (see also music and emotion). In history, scholars examine documents and other sources to interpret and analyse past activities; speculation on the emotional state of the authors of historical documents is one of the tools of interpretation. In literature and film-making, the expression of emotion is the cornerstone of genres such as drama, melodrama, and romance. In communication studies, scholars study the role that emotion plays in the dissemination of ideas and messages. Emotion is also studied in non-human animals in ethology, a branch of zoology which focuses on the scientific study of animal behaviour. Ethology is a combination of laboratory and field science, with strong ties to ecology and evolution. Ethologists often study one type of behaviour (for example, aggression) in a number of unrelated animals.

History

The history of emotions has become an increasingly popular topic recently, with some scholars[who?] arguing that it is an essential category of analysis, not unlike class, race, or gender. Historians, like other social scientists, assume that emotions, feelings and their expressions are regulated in different ways by both different cultures and different historical times, and the constructivist school of history claims even that some sentiments and meta-emotions, for example schadenfreude, are learnt and not only regulated by culture. Historians of emotion trace and analyse the changing norms and rules of feeling, while examining emotional regimes, codes, and lexicons from social, cultural, or political history perspectives. Others focus on the history of medicine, science, or psychology. What somebody can and may feel (and show) in a given situation, towards certain people or things, depends on social norms and rules; thus historically variable and open to change. Several research centres have opened in the past few years in Germany, England, Spain, Sweden, and Australia.

Furthermore, research in historical trauma suggests that some traumatic emotions can be passed on from parents to offspring to second and even third generation, presented as examples of transgenerational trauma.

Sociology

A common way in which emotions are conceptualized in sociology is in terms of the multidimensional characteristics including cultural or emotional labels (for example, anger, pride, fear, happiness), physiological changes (for example, increased perspiration, changes in pulse rate), expressive facial and body movements (for example, smiling, frowning, baring teeth), and appraisals of situational cues. One comprehensive theory of emotional arousal in humans has been developed by Jonathan Turner (2007; 2009). Two of the key eliciting factors for the arousal of emotions within this theory are expectations states and sanctions. When people enter a situation or encounter with certain expectations for how the encounter should unfold, they will experience different emotions depending on the extent to which expectations for Self, other and situation are met or not met. People can also provide positive or negative sanctions directed at Self or other which also trigger different emotional experiences in individuals. Turner analysed a wide range of emotion theories across different fields of research including sociology, psychology, evolutionary science, and neuroscience. Based on this analysis, he identified four emotions that all researchers consider being founded on human neurology including assertive-anger, aversion-fear, satisfaction-happiness, and disappointment-sadness. These four categories are called primary emotions and there is some agreement amongst researchers that these primary emotions become combined to produce more elaborate and complex emotional experiences. These more elaborate emotions are called first-order elaborations in Turner’s theory and they include sentiments such as pride, triumph, and awe. Emotions can also be experienced at different levels of intensity so that feelings of concern are a low-intensity variation of the primary emotion aversion-fear whereas depression is a higher intensity variant.

Attempts are frequently made to regulate emotion according to the conventions of the society and the situation based on many (sometimes conflicting) demands and expectations which originate from various entities. The expression of anger is in many cultures discouraged in girls and women to a greater extent than in boys and men (the notion being that an angry man has a valid complaint that needs to be rectified, while an angry women is hysterical or oversensitive, and her anger is somehow invalid), while the expression of sadness or fear is discouraged in boys and men relative to girls and women (attitudes implicit in phrases like “man up” or “don’t be a sissy”). Expectations attached to social roles, such as “acting as man” and not as a woman, and the accompanying “feeling rules” contribute to the differences in expression of certain emotions. Some cultures encourage or discourage happiness, sadness, or jealousy, and the free expression of the emotion of disgust is considered socially unacceptable in most cultures. Some social institutions are seen as based on certain emotion, such as love in the case of contemporary institution of marriage. In advertising, such as health campaigns and political messages, emotional appeals are commonly found. Recent examples include no-smoking health campaigns and political campaigns emphasizing the fear of terrorism.

Sociological attention to emotion has varied over time. Émile Durkheim (1915/1965) wrote about the collective effervescence or emotional energy that was experienced by members of totemic rituals in Australian aborigine society. He explained how the heightened state of emotional energy achieved during totemic rituals transported individuals above themselves giving them the sense that they were in the presence of a higher power, a force, that was embedded in the sacred objects that were worshipped. These feelings of exaltation, he argued, ultimately lead people to believe that there were forces that governed sacred objects.

In the 1990s, sociologists focused on different aspects of specific emotions and how these emotions were socially relevant. For Cooley (1992), pride and shame were the most important emotions that drive people to take various social actions. During every encounter, he proposed that we monitor ourselves through the “looking glass” that the gestures and reactions of others provide. Depending on these reactions, we either experience pride or shame and this results in particular paths of action. Retzinger (1991) conducted studies of married couples who experienced cycles of rage and shame. Drawing predominantly on Goffman and Cooley’s work, Scheff (1990) developed a micro sociological theory of the social bond. The formation or disruption of social bonds is dependent on the emotions that people experience during interactions.

Subsequent to these developments, Randall Collins (2004) formulated his interaction ritual theory by drawing on Durkheim’s work on totemic rituals that was extended by Goffman (1964/2013; 1967) into everyday focused encounters. Based on interaction ritual theory, we experience different levels or intensities of emotional energy during face-to-face interactions. Emotional energy is considered to be a feeling of confidence to take action and a boldness that one experiences when they are charged up from the collective effervescence generated during group gatherings that reach high levels of intensity.

There is a growing body of research applying the sociology of emotion to understanding the learning experiences of students during classroom interactions with teachers and other students (for example, Milne & Otieno, 2007; Olitsky, 2007; Tobin, et al., 2013; Zembylas, 2002). These studies show that learning subjects like science can be understood in terms of classroom interaction rituals that generate emotional energy and collective states of emotional arousal like emotional climate.

Apart from interaction ritual traditions of the sociology of emotion, other approaches have been classed into one of six other categories:

  • Evolutionary/biological theories.
  • Symbolic interactionist theories.
  • Dramaturgical theories.
  • Ritual theories.
  • Power and status theories.
  • Stratification theories.
  • Exchange theories.

This list provides a general overview of different traditions in the sociology of emotion that sometimes conceptualise emotion in different ways and at other times in complementary ways. Many of these different approaches were synthesized by Turner (2007) in his sociological theory of human emotions in an attempt to produce one comprehensive sociological account that draws on developments from many of the above traditions.

Psychotherapy and Regulation

Emotion regulation refers to the cognitive and behavioural strategies people use to influence their own emotional experience. For example, a behavioural strategy in which one avoids a situation to avoid unwanted emotions (trying not to think about the situation, doing distracting activities, etc.). Depending on the particular school’s general emphasis on either cognitive components of emotion, physical energy discharging, or on symbolic movement and facial expression components of emotion different schools of psychotherapy approach the regulation of emotion differently. Cognitively oriented schools approach them via their cognitive components, such as rational emotive behaviour therapy. Yet others approach emotions via symbolic movement and facial expression components (like in contemporary Gestalt therapy).

Cross-Cultural Research

Research on emotions reveals the strong presence of cross-cultural differences in emotional reactions and that emotional reactions are likely to be culture-specific. In strategic settings, cross-cultural research on emotions is required for understanding the psychological situation of a given population or specific actors. This implies the need to comprehend the current emotional state, mental disposition or other behavioural motivation of a target audience located in a different culture, basically founded on its national political, social, economic, and psychological peculiarities but also subject to the influence of circumstances and events.

Computer Science

In the 2000s, research in computer science, engineering, psychology and neuroscience has been aimed at developing devices that recognise human affect display and model emotions. In computer science, affective computing is a branch of the study and development of artificial intelligence that deals with the design of systems and devices that can recognise, interpret, and process human emotions. It is an interdisciplinary field spanning computer sciences, psychology, and cognitive science. While the origins of the field may be traced as far back as to early philosophical enquiries into emotion, the more modern branch of computer science originated with Rosalind Picard’s 1995 paper on affective computing. Detecting emotional information begins with passive sensors which capture data about the user’s physical state or behaviour without interpreting the input. The data gathered is analogous to the cues humans use to perceive emotions in others. Another area within affective computing is the design of computational devices proposed to exhibit either innate emotional capabilities or that are capable of convincingly simulating emotions. Emotional speech processing recognises the user’s emotional state by analysing speech patterns. The detection and processing of facial expression or body gestures is achieved through detectors and sensors.

The Effects on Memory

Emotion affects the way autobiographical memories are encoded and retrieved. Emotional memories are reactivated more, they are remembered better and have more attention devoted to them. Through remembering our past achievements and failures, autobiographical memories affect how we perceive and feel about ourselves.

Notable Theorists

In the late 19th century, the most influential theorists were William James (1842-1910) and Carl Lange (1834-1900). James was an American psychologist and philosopher who wrote about educational psychology, psychology of religious experience/mysticism, and the philosophy of pragmatism. Lange was a Danish physician and psychologist. Working independently, they developed the James-Lange theory, a hypothesis on the origin and nature of emotions. The theory states that within human beings, as a response to experiences in the world, the autonomic nervous system creates physiological events such as muscular tension, a rise in heart rate, perspiration, and dryness of the mouth. Emotions, then, are feelings which come about as a result of these physiological changes, rather than being their cause.

Silvan Tomkins (1911-1991) developed the affect theory and script theory. The affect theory introduced the concept of basic emotions, and was based on the idea that the dominance of the emotion, which he called the affected system, was the motivating force in human life.

Some of the most influential deceased theorists on emotion from the 20th century include:

  • Magda B. Arnold (1903-2002), an American psychologist who developed the appraisal theory of emotions;
  • Richard Lazarus (1922-2002), an American psychologist who specialised in emotion and stress, especially in relation to cognition;
  • Herbert A. Simon (1916-2001), who included emotions into decision making and artificial intelligence;
  • Robert Plutchik (1928-2006), an American psychologist who developed a psychoevolutionary theory of emotion;
  • Robert Zajonc (1923-2008) a Polish-American social psychologist who specialised in social and cognitive processes such as social facilitation;
  • Robert C. Solomon (1942-2007), an American philosopher who contributed to the theories on the philosophy of emotions with books such as What Is An Emotion?: Classic and Contemporary Readings (2003);
  • Peter Goldie (1946-2011), a British philosopher who specialised in ethics, aesthetics, emotion, mood and character;
  • Nico Frijda (1927-2015), a Dutch psychologist who advanced the theory that human emotions serve to promote a tendency to undertake actions that are appropriate in the circumstances, detailed in his book The Emotions (1986); and
  • Jaak Panksepp (1943-2017), an Estonian-born American psychologist, psychobiologist, neuroscientist and pioneer in affective neuroscience.

Influential theorists who are still active include the following psychologists, neurologists, philosophers, and sociologists:

  • Lisa Feldman Barrett (born 1963): Neuroscientist and psychologist specializing in affective science and human emotion.
  • John Cacioppo (born 1951): From the University of Chicago, founding father with Gary Berntson of social neuroscience.
  • Randall Collins (born 1941): American sociologist from the University of Pennsylvania developed the interaction ritual theory which includes the emotional entrainment model.
  • Michael Apter (born 1939): British psychologist who developed reversal theory, a structural, phenomenological theory of personality, motivation, and emotion.
  • António Damásio (born 1944): Portuguese behavioural neurologist and neuroscientist who works in the US.
  • Richard Davidson (born 1951): American psychologist and neuroscientist; pioneer in affective neuroscience.
  • Paul Ekman (born 1934): Psychologist specialising in the study of emotions and their relation to facial expressions.
  • Barbara Fredrickson: Social psychologist who specialises in emotions and positive psychology.
  • Arlie Russell Hochschild (born 1940): American sociologist whose central contribution was in forging a link between the subcutaneous flow of emotion in social life and the larger trends set loose by modern capitalism within organisations.
  • Joseph E. LeDoux (born 1949): American neuroscientist who studies the biological underpinnings of memory and emotion, especially the mechanisms of fear.
  • George Mandler (born 1924): American psychologist who wrote influential books on cognition and emotion.
  • Konstantinos V. Petrides: Greek-British psychologist who specialises in emotion, personality, psychometrics, and philosophy of mind, professor of psychology and psychometrics at University College London.
  • Jesse Prinz: American philosopher who specialises in emotion, moral psychology, aesthetics and consciousness.
  • James A. Russell (born 1947): American psychologist who developed or co-developed the PAD theory of environmental impact, circumplex model of affect, prototype theory of emotion concepts, a critique of the hypothesis of universal recognition of emotion from facial expression, concept of core affect, developmental theory of differentiation of emotion concepts, and, more recently, the theory of the psychological construction of emotion.
  • Klaus Scherer (born 1943): Swiss psychologist and director of the Swiss Centre for Affective Sciences in Geneva; he specialises in the psychology of emotion.
  • Ronald de Sousa (born 1940): English-Canadian philosopher who specialises in the philosophy of emotions, philosophy of mind and philosophy of biology.
  • Jonathan H. Turner (born 1942): American sociologist from the University of California, Riverside, who is a general sociological theorist with specialty areas including the sociology of emotions, ethnic relations, social institutions, social stratification, and bio-sociology.
  • Dominique Moïsi (born 1946): Authored a book titled The Geopolitics of Emotion focusing on emotions related to globalisation.

Book: Sleep Medicine and Mental Health

Book Title:

Sleep Medicine and Mental Health – A Guide for Psychiatrists and Other Healthcare Professionals.

Author(s): Karim Sedky, Racha Nazir, and David Bennett (Editors).

Year: 2020.

Edition: First (1st).

Publisher: Springer.

Type(s): Hardcover and Kindle.

Synopsis:

Advances in sleep medicine research are improving our clinical work for individuals with sleep problems. The aim of this book is to educate psychiatrists and other mental health professionals about the importance of understanding sleep disorders, including their bidirectional relationship with psychiatric conditions.

This book consists of six major sections with seventeen chapters. It is led off by an introduction on the function of sleep, its neurophysiology, and types of sleep problems. Since insomnia represents a common and significant challenge for patients with psychiatric disorders, its clinical presentation and treatments are reviewed in the second section. Cognitive behavioural therapy for insomnia (CBT-I), mindfulness-based CBT, acceptance and commitment therapy (ACT), and the medication management of insomnia are reviewed.

A third section addresses sleep related breathing disorders. The pathology of sleep apnea, its treatments, and therapeutic modalities to address non-compliance with positive pressure ventilation are reviewed. Other sleep disorders such as hypersomnia, circadian rhythm disorders, movement disorders and parasomnias are discussed in the fourth section.

Since features of sleep disorders can vary by age, gender, and trauma history, a fifth section discusses the unique sleep problems associated with children, women, older adults, and veterans. The book concludes with a final section discussing how sleep disorders and psychiatric conditions overlap.

We hope this book highlights the importance of understanding and addressing comorbid sleep disorders among individuals with psychiatric conditions. We are confident that this book will be valuable in helping clinicians improve the management of sleep disorders in their clinical practice.

Mental Stress Tasks & the Prefrontal Cortex

Research Paper Title

Relationship Between Cerebral Blood Oxygenation and Electrical Activity During Mental Stress Tasks: Simultaneous Measurements of NIRS and EEG.

Background

The incidence of stress-induced psychological and somatic diseases has been increasing rapidly, and it is important to clarify the neurophysiological mechanisms of stress response in order to establish effective stress management methods.

The researchers previously reported that the prefrontal cortex (PFC) plays an important role in stress response.

Methods

In the present study, the researchers employed near-infrared spectroscopy (NIRS) and electroencephalography (EEG) to investigate the characteristics of PFC activity during mental arithmetic tasks.

A two-channel NIRS device was used to measure haemoglobin (Hb) concentration changes in the bilateral PFC during a mental arithmetic task (2 min) in normal adults.

Simultaneously, EEG was used to also measure bilateral PFC activity during the same task.

They evaluated concentration changes of oxy-Hb induced by the task while analysing α wave changes using power spectrum analysis.

Results

It was observed that oxy-Hb in the bilateral PFC increased significantly during the task (p < 0.05), while α wave power in the PFC decreased significantly (p < 0.01).

Conclusions

The present results indicate that mental stress tasks caused the activation of the bilateral PFC.

Simultaneous measurements of NIRS and EEG are useful for evaluating the neurophysiological mechanism of stress responses in the brain.

Reference

Nagasawa, Y., Ishida, M., Komuro, Y., Ushioda, S., Hu, L. & Sakatani, K. (2020) Relationship Between Cerebral Blood Oxygenation and Electrical Activity During Mental Stress Tasks: Simultaneous Measurements of NIRS and EEG. Advances in Experimental Medicine and Biology. 1232:99-104. doi: 10.1007/978-3-030-34461-0_14.

Linking Spatial Working Memory, Affective Disorders, & Mild Current Depression

Research Paper Title

[Disorders of spatial working memory in affective disorders with mild current depression and their neurophysiological correlates].

Background

To assess spatial working memory disorders in patients with mild depressive disorders and determine their neurophysiological correlates.

Methods

Thirty patients (right-handed) with ICD-10 diagnosis Mood Disorders (F31.3, F32.0, F33.0, F34.1), aged 37±8 years, were examined before treatment. A control group included 30 mentally and somatically healthy individuals (32±7 years old). The study of spatial working memory was carried out using the Corsi Block-Tapping test. EEG was recorded and the values of the spectral power of theta, alpha and beta rhythms were analysed.

Results and Conclusions

A decrease in the level of working memory that was correlated with higher values of theta rhythm power in the frontal and occipital regions and alpha rhythm in the frontal cortex was observed in affective disorders with mild depressive symptoms.

Reference

Galkin, S.A., Peshkovskaya, A.G., Simutkin, G.G., Vasil’eva, S.N., Roshchina, O.V., Ivanova, S.A. & Bokhan, N.A. (2019) [Disorders of spatial working memory in affective disorders with mild current depression and their neurophysiological correlates]. (in Russian). Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova. 119(10):56-61. doi: 10.17116/jnevro201911910156.