Punishment Learning in U.S. Veterans With Posttraumatic Stress Disorder

Abstract

Learning processes have been implicated in the development and course of posttraumatic stress disorder (PTSD); however, little is currently known about punishment-based learning in PTSD. The current study investigated impairments in punishment-based learning in U.S. veterans. We expected that veterans with PTSD would demonstrate greater punishment-based learning compared to a non-PTSD control group. We compared a PTSD group with and without co-occurring depression (n = 27) to a control group (with and without trauma exposure) without PTSD or depression (n = 29). Participants completed a computerized probabilistic punishment-based learning task. Compared to the non-PTSD control group, veterans with PTSD showed significantly greater punishment-based learning. Specifically, there was a significant Block × Group interaction, F(1, 54) = 4.12, p = .047, η(2) = .07. Veterans with PTSD demonstrated greater change in response bias for responding toward a less frequently punished stimulus across blocks. The observed hypersensitivity to punishment in individuals with PTSD may contribute to avoidant responses that are not specific to trauma cues.