Research Digest

Adolphs, R., Tranel, D., & Buchanan, T. W. (2005). Amygdala damage impairs emotional memory for gist but not details of complex stimuli.  Nature Neuroscience,  8:  512-518.

We have long known two rather independent facts, in diverse fields, that are brought together in this interesting paper. First, in neuroscience we know that the amygdala is involved in several aspects of emotion, most notably as regards the memory of events (especially fearful situations). Second, in clinical psychology, we have also long known that patients with mental health problems have difficulty recalling specific aspects of their previous life experience: some (for example, in depression) seem especially impaired in recalling gist rather than detail, while the converse is true for other states (those of an anxious or traumatic nature). This latter finding is especially important for psychoanalysis and related psychotherapies because so much of the therapeutic experience is mediated by the ability of the client to consciously recall his or her life experiences and to place them in a coherent narrative. The findings of Adolphs et al. bring together these two strands and allow us to better understand the role of emotion in the reexperiencing of a personal narrative in studies of patients with focal lesions to the amygdala and related structures. The patients are asked to recall images that may be neutral (a car ride for relaxation) or emotionally valenced (a car ride to recover the body of a dead child), with later questions about gist (e.g., who are the characters in the image) or details (background specifics, such as cloud formations). The findings show that the amygdala seems to be central for the recall of gist, while the hippocampus is critical for the recall of detail—with selective loss of each category after selective lesions. We also know that powerful affective experiences are associated with enormous changes in hormones, such as cortiso