Introduction to emotion

Emotion, in its most general definition, is a neural impulse that moves an organism to action, prompting automatic reactive behavior that has been adapted through evolution as a survival mechanism to meet a survival need. Linda Davidoff defines emotion as a feeling that is expressed through physiological functions such as facial expressions, faster heartbeat, and behaviors such as aggression, crying, or covering the face with hands. Examples of emotions are joy, anger, fear, disgust, surprise, and empathy.

Emotion is differentiated from feeling, in that, as noted, emotion is a psycho-physiological state that moves an organism to action. Feeling, on the other hand, is emotion that is filtered through the cognitive brain centers, specifically the frontal lobe, producing a physiological change in addition to the psycho-physiological change. Daniel Goleman, in his landmark book Emotional Intelligence, discusses this differentiation at length.

Elaborations
Emotion is complex, and the term has no single universally accepted definition. Emotions are mental states that arise spontaneously, rather than through conscious effort. It is unclear whether animals or all human beings experience emotion. Emotions are physical expressions, often involuntary, related to feelings, perceptions or beliefs about elements, objects or relations between them, in reality or in the imagination. The study of emotions is part of psychology, neuroscience, and, more recently, artificial intelligence. According to Sloman, emotions are cognitive processes. Some authors emphasize the difference between human emotions and the affective behavior of animals.

Emotion is sometimes regarded as the antithesis of reason. This is reflected in common phrases like appeal to emotion or your emotions have taken over. Emotions can be undesired to the individual feeling them; he or she may wish to control but often cannot. Thus one of the most distinctive, and perhaps challenging, facts about human beings is this potential for entanglement, or even opposition, between will, emotion, and reason.

Emotion as the subject of scientific research has multiple dimensions: behavioral, physiological, subjective, and cognitive. Sloman and others explain that the need to face a changing and unpredictable world makes emotions necessary for any intelligent system (natural or artificial) with multiple motives and limited capacities and resources.

Current research on the neural circuitry of emotion suggests that emotion makes up an essential part of human decision-making, including long-term planning, and that the famous distinction made by Descartes between reason and emotion is not as clear as it seems.

Some state that there is no empirical support for any generalization suggesting the antithesis between reason and emotion: indeed, anger or fear can often be thought of as a systematic response to observed facts. What can be noted, however, is that the human psyche possesses many possible reactions and perspectives in response to the internal and external world - often lying on a continuum&#8212; at one extreme lies pure intellectual logic (often called "cold"); at the other extreme is pure emotionally unresponsive to logical argument ("the heat of passion"). In any case, it is clear that the relation between logic and argument on the one hand and emotion on the other, is one which merits careful study. It has been noted by many that passion, emotion, or feeling can add backing to an argument, even one based primarily on reason - particularly regarding religion or ideology, areas of human thought which frequently demand an all-or-nothing rejection or acceptance, that is, the adoption of a comprehensive worldview partly backed by empirical argument and partly by feeling and passion. Moreover, it has been suggested by several researchers that typically there is no "pure" decision or thought, that is, no thought based "purely" on intellectual logic or "purely" on emotion - most decisions and cognitions are founded on a mixture of both.

Pyschiatrist William Glasser's theory of the human control system states that all human behavior is composed of four simultaneous components: deeds, ideas, emotions, and physiological states. He asserts that we choose the idea and deed and that the associated emotions and physiological states also occur but cannot be chosen independently. He calls his construct a total behavior to distinguish it from the common concept of behavior. He uses the verbs to describe what is commonly seen as emotion. For example, he uses 'to depress' to describe the total behavior commonly known as depression which, to him, includes depressing ideas, actions, emotions, and physiological states. Dr. Glasser also further asserts that internal choices (conscious or unconcious) cause emotions instead of external stimuli.

Relation to cultural and social factors
It is not clear whether emotion is a purely human phenomenon, since animals seem to exhibit conditions which resemble emotional responses such as anger, fear or sadness, and some animals also exhibit similar neural phenomena to humans in tandem with possible emotional response.

It has been hypothesized that emotions typical of human beings have evolved and changed in many ways since the species first emerged. Nonetheless, as noted above, it may well be the case that human and non-human animal emotional responses lie on a constant continuum, rather than being two completely distinct categories of human and animal.

Much of what is said about emotions, as well as the history of what has been said about them, is conditioned by culture and even politics. That is to say specific emotional responses, as well as a group's interpretation of their significance, may be influenced by cultural norms of propriety. For instance, certain emotions such as love, hate, and the desire for vengeance are treated very differently in differing societies. This methodological relativity is entirely different from the question of whether emotions are universal or are culturally determined. Many researchers would agree that a vast proportion of human behavior, no matter how close to the lowest biological substrates - including sexual behavior, food consumption, feelings in response to physiological changes and responses to environmental conditions - are conditioned based on social surroundings and non-human environmental factors. Thus it is not difficult to defend the position that emotion is, to a high degree, dependent on social phenomena, expectations, norms, and conditioned behavior of the group in which an individual lives. The influence of politics, religion, and socio-cultural customs can be sometimes traced or hypothesized. Among many pertinent examples: behaviors or activities considered highly cruel in some societies may in fact provoke responses of enjoyment in others; or, sexual acts considered highly desirable in some cultures would provoke shame or disgust in others.

Contrary to this view, Paul Ekman has shown that at least some facial expressions and their corresponding emotions are universal across human cultures and are not culturally determined. These universal emotions include anger, disgust, fear, joy, sadness and surprise.

Theoretical traditions
According to Cornelius (1996), four main theoretical traditions have dominated research in emotions starting in the 1800's with Darwin's observations of emotion in man and animals. These traditions are not mutually exclusive and many researchers incorporate multiple perspectives in their work.

First articulated in the late 19th century by Charles Darwin, emotions evolved via natural expression and therefore have cross-culturally universal counterparts. Most research in this area has focused on physical displays of emotion including body language of animals and facial expressions in humans. Paul Ekman's work on basic emotions is representative of the Darwinian tradition.
 * The Darwinian perspective

William James in the 1800's believed that emotional experience is largely due to the experience of bodily changes. These changes might be visceral, postural, or facially expressive.
 * The Jamesian perspective

Many researchers believe that thought and in particular cognitive appraisal of the environment is an underlying causal explanation for emotional processes.
 * The cognitive perspective

Social constructivism emphasizes the importance of culture and context in understanding what occurs in society and constructing knowledge based on this understanding (Derry, 1999; McMahon, 1997). Much current research in emotion is based on the social constructivist view.
 * The social constructivist perspective

This tradition draws on recent work on neurophysiology and neuroanatomy to explain the nature of emotions. LeDoux (1986) reviews relatively current knowledge on the neurophysiology of emotion.
 * The neurological tradition (Plutchik, 1980)

Etymology
Etymologically, the word emotion is a composite formed from two Latin words. ex/out, outward + motio/movement, action, gesture. This classical formation refers to the immediate nature of emotion as experienced by humans and attributed in some cultures and ways of thinking to all living organisms, and by scientific community to any creature that exhibits complex response traits similar to what humans refer to as emotion.

Physical responses to emotion
The body frequently responds to Shame by warmth in the upper chest and face, Fear by a heightened heartbeat, increased "flinch" response, and increased muscle tension. The sensations connected with anger are nearly indistinguishable from fear. Happiness is often felt as an expansive or swelling feeling in the chest and the sensation of lightness or buoyancy, as if standing underwater. Sadness by a feeling of tightness in the throat and eyes, and relaxation in the arms and legs. Desire can be accompanied by a dry throat and heavy breathing

Computer models of emotion
A flurry of recent work in modeling emotional circuitry and recognition has come out of computer science, engineering, psychology and neuroscience (c.f. Fellous, Armony & LeDoux, 2002).
 * See affective computing
 * Neural network models of emotion recognition

References and notes

 * 1) Cornelius, R. (1996). The science of emotion. New Jersey: Prentice Hall.
 * 2) Damasio AR. (1994). "Descartes' Error." Penguin Putnam, New York, New York.
 * 3) Darwin, C. (1872). The Expression of Emotions in Man and Animals. This was originally published in 1872. It has been reprinted many times thereafter. See, e.g., London: Julian Friedmann Publishers, 1979 (with an introduction by S.J. Rachman.)
 * 4)  Davidoff, Linda. 1980, 2a. Introducción a la Psicología, McGraw-Hill. México.
 * 5) Ekman P. (1999). "Facial Expressions" in Handbook of Cognition and Emotion. Dalgleish T & Power M, Eds. John Wiley & Sons Ltd. New York, New York.
 * 6) Fellous, J.M., Armony, J.L., & LeDoux, J.E. (2002). "Emotional Circuits and Computational Neuroscience" in 'The handbook of brain theory and neural networks' Second Edition. M.A. Arbib (editor), The MIT Press.
 * 7) Frijda, Nico H. (1986). The Emotions. Maison des Sciences de l'Homme and Cambridge University Press.
 * 8) LeDoux, J.E. (1986). The neurobiology of emotion. Chap. 15 in J E. LeDoux & W. Hirst (Eds.) Mind and Brain: diologues in cognitive neuroscience. New York: Cambridge.
 * 9) Plutchik, R. (1980). A general psychoevolutionary theory of emotion. In R. Plutchik & H. Kellerman (Eds.), Emotion: Theory, research, and experience: Vol. 1. Theories of emotion (pp. 3-33). New York: Academic.
 * 10)  Sloman, Aaron. 1981. Why Robots Will Have Emotions. University of Sussex. In proc.

Emotion researchers

 * Wiliam James
 * Charles Darwin
 * Ivan Pavlov
 * James Papez
 * Paul D. MacLean
 * Sigmund Freud
 * Carl Jung
 * Carl Rogers
 * Paul Ekman
 * Antonio Damasio
 * Robert Plutchik
 * Aaron Ben-Ze'ev
 * Joseph LeDoux
 * Nico Frijda
 * Keith Oatley
 * Robert Zajonc
 * Alice Isen
 * Spinoza