The effects of contextual threat and anxiety on affective startle modulation

Abstract

The startle reflex is attenuated and potentiated when participants are viewing pleasant and unpleasant images, respectively. Research demonstrates that threatening contexts also potentiate startle, but it remains unclear how a threatening context might impact startle modulation to emotional images, especially as a function of trait anxiety. The present study measured startle reactivity while 43 participants viewed pleasant, unpleasant, and neutral images across conditions of threat-of-shock and safety (i.e., no shock). Compared to neutral images, startle was potentiated during unpleasant images and attenuated during pleasant images. Threat-of-shock potentiated startle during all picture types, suggesting that threat-of-shock broadly sensitized the defensive system but did not change affective modulation of startle. Lastly, higher levels of trait anxiety were associated with less startle potentiation during unpleasant images across both conditions—a finding in line with previous research demonstrating deficient threat mobilization in response to unpleasant stimuli among highly anxious individuals.