Aversive perception in a threat context: Separate and independent neural activation

Abstract

Unpleasant, compared to neutral, scenes reliably prompt enhanced functional brain activity in the amygdala and inferotemporal cortex. Considering data from psychophysiological studies in which defensive reactivity is further enhanced when viewing unpleasant scenes under threat of shock (compared to safety), the current study investigates functional activation in the amygdala-inferotemporal circuit when unpleasant (or neutral) scenes are viewed under threat of shock or safety. In this paradigm, a cue signaling threat or safety was presented in conjunction with either an unpleasant or neutral picture. Replicating previous studies, unpleasant, compared to neutral, scenes reliably enhanced activation in the amygdala and inferotemporal cortex. Functional activity in these regions, however, did not differ whether scenes were presented in a context threatening shock exposure, compared to safety, which instead activated regions of the anterior insula and cingulate cortex. Taken together, the data support a view in which neural regions activated in different defensive situations act independently.

Keywords: Affective scenes; Amygdala; Anterior insula; Threat of shock; fMRI.

Figure 1.

A. The time course and bar plots of BOLD signal in both inferotemporal cortex and amygdala shows enhanced functional activity when viewing unpleasant compared to neutral scenes, regardless of the context in which scenes were presented (threat or safety). B. Anterior insula time course shows enhanced functional activity when pictures were presented under threat compared to safety, regardless of the emotional content of the scenes (unpleasant or neutral).