The study of the emotions has been relatively neglected by neuroscientists, cognitive scientists, and philosophers, but recently the tide has been turning. Some important recent work includes Antonio Damasio’s The Feeling of What Happens, Paul Redding’s The Logic of Affect, Edmund Rolls’s The Brain and Emotion, and Paul E. Griffiths’s What Emotions Really Are. Joseph LeDoux’s The Emotional Brain: The Mysterious Underpinnings of Emotional Life is slightly older than these others, having been in print since 1996. It remains one of the better technical ones for the lay reader and eminently accessible.

LeDoux is a neuroscientist with the Center for Neural Science at New York University. His book showcases his research on the biological underpinnings of fear. An almond sized and shaped part of the brain, the amygdala, is primarily responsible for fearful behavior. When one responds fearfully to a significant stimulus, such as a nearby growling brown bear, the response is automatic. The amygdala mediates between the stimulus, in this case, the brown bear, and the fearful bodily reaction. The amygdala prepares a person’s body; heart rate increases, stress hormones are released, blood pressure rises, and attention is focused. The body is geared for freezing, fleeing, or fighting.

At times like these one almost never thinks to oneself that one is facing immediate, concrete, and overwhelming physical danger. The feeling of fear is immediate. Afterward one might evaluate the circumstances as indeed involving immediate physical danger. A conscious appraisal of an emotional event seems to follow our experience of feeling fear.

LeDoux proposes an even more radical view. The fear, itself, is prior even to our feeling fear. On this view, emotions are largely unconscious. For LeDoux, experiencing an emotion is a puzzle about consciousness rather than one about emotions. He speculates in the last chapter about the mechanism that mediates an emotional feeling. Still the road toward the emotions is not via feelings. This is a highly welcomed view, and it is one aspect of his theory that sets him apart from other researchers.

LeDoux discusses a number of topics, including the inadequacies of the limbic system theory of emotion, the neural system that mediates fear conditioning, the role memories play in forming our emotional reactions, understanding the molecular and cellular basis of learning, and the relationship between the “high road” of the neocortex and the “low road” of the amygdala. His themes are introduced and discussed not as dry reports for the scientific community but as the investigation or resolution of unanswered questions or conundrums.

The book ends up being an exceptionally useful series of mini-voyages. The reader faces a scientific problem and receives, most of the time, a satisfying resolution. Happily, these scientific voyages are free of superfluous technical information. Whenever technical information is introduced, it is adequately explained. More significantly, the reader understands how that information is an important step in developing LeDoux’s theory about the neural basis for fear.

In the initial chapters, LeDoux presents a very readable historical introduction. Like many current writers on the emotions, LeDoux rejects an approach on which the emotions are essentially cognitive. Being afraid is a matter of cognitively assessing a threat, being sad, a loss or failure, and so forth. It is the cognitive appraisal of a situation that differentiates one emotion from another. Feelings are not sufficiently distinctive to individuate the emotions, according to this view.

A standard criticism of the cognitive approach is its apparent failure to account for the feelings associated with an emotional experience. But a cognitivist could adopt the same move LeDoux makes, claiming that emotional feelings are a matter of consciousness and not the emotions, themselves. I suspect that two factors are central to LeDoux’s rejection of the cognitive approach. The first is his argument against the value of introspective reports in understanding the emotions. The second is the finding showing a neural separation between the evolutionarily older fear system and the evolutionarily younger higher cognitive systems associated with the neocortex.