Emotion, Placebo, and Ethics in Neuroscience

Anderson, A. K., & Phelps, E. A. (2002). Is the human amygdala critical for the subjective experience of emotion? Evidence of intact dispositional affect in patients with amygdala lesions.  Journal of Cognitive Neuro science,  14:  709-720.

Zald, D. H. (2003). The human amygdala and the emotional evaluation of sensory stimuli.  Brain Research Reviews,  41:  88-123

If there is one brain region that has been promoted as the “centre” for emotion in recent years, it is the amygdala. This focus has been primarily because of a comprehensive series of findings begun from the work of LeDoux, and it has led to something of a reification of this brain structure. LeDoux (1996) himself has always been careful to point out that his work focuses only on one emotion (fear) and, indeed, only one aspect of fear (its memorial role in fear conditioning), but this appears not to have stopped others from assuming that the amygdala is where emotion happens. The regular activation of the amygdala in functional imaging investigations of emotion has confirmed this view. There have been others (notably Panksepp, 1998) who have pointed out that there is a range of other brain regions that appear to be engaged in emotion, that fear does not rely only on the amygdala, and, indeed, that electrical stimulation of many other brain areas produces even more intense fearful responses. Perhaps, it has been argued, the amygdala is involved only in the memorial aspects of fear, and other subcortical structures are central for the subjective experience of fear. However, this conclusion has been derived largely from work on animals and has awaited the systematic evaluation of subjective experience in humans. Because investigating subjective affective states remains (strangely enough) of low priority for many emotion researchers, we have waited for some time for a clear answer: this is now offered by the Anderson & Phelps and the Zald papers. Their data show that patients with amygdala damage—left