The Biopsychology of Trauma and Memory

This chapter examines the biopsychology of trauma and how it influences memory. It argues that trauma (and, more precisely, the stress that usually accompanies trauma) has identifiable effects on the hippocampus, impairing both the neuronal structure and the function of this brain region. As a direct consequence, stress (especially uncontrollable stressors) impairs various forms of memory. However, not all memories suffer this effect, and the chapter seeks to explain this point by arguing that the experience of stress (through its impact on the hippocampus) causes stressful events to be recorded in a fragmented manner, with the elements of the event not woven into a coherent remembered episode. At the same time, emotion works (via the amygdala) to promote memory for the gist of an event, leading to well-encoded memories for the thematic content of an emotion event, but, again, without the coherent spatiotemporal framework needed to organize the memory (because this framework relies on hippocampal circuits disrupted by stress).