Both mental imagery and object-based attention regulate differential fear conditioning in the anterior insula

Distraction is a common emotion regulation strategy, disrupting emotion generation by prioritizing distracter stimulus processing at the expense of the emotion elicitor. Across two experiments (experiment 1: behavioral psychophysiology, N = 44; experiment 2: neuroimaging with psychophysiology, N = 28), we predicted that both object-based (external) and mental imagery-based (internal) distraction would down-regulate differential fear responding. Participants underwent differential fear conditioning, pairing one face image with shock (CS+) while another face image was never paired with shock (CS-). Participants then viewed face/place composite images and were cued to attend to the face (CS+ or CS-) or distract themselves. Distraction was achieved either by attending to a superimposed place image (external distraction) or imagining a place image (internal distraction). Skin conductance response, self-reported fear, and anterior insula (aIn) results confirmed the acquisition of differential fear. Self-reported fear and aIn results evidenced fear down-regulation in both object-based and imagery-based distraction. Activity in stimulus-specific regions of the ventral visual stream suggested that fear down-regulation occurred via prioritization of the visually displayed or imagined distracter, inhibiting CS+ processing. Though effective, internal distraction was rated as more difficult than external distraction. Together, these findings suggest that both object-based and mental imagery-based distraction successfully down-regulated differential fear responding.