Seated movement indexes emotion and its regulation in posttraumatic stress disorder

This paper reports the results of a study that administered an emotion regulation task to Operation Enduring Freedom/Operation Iraqi Freedom veterans diagnosed with posttraumatic stress disorder (27) and to healthy controls (23). Seated movement and postural responses were transduced with a sensitive accelerometer attached to the underside of a low-mass cantilevered chair. Consistent with prior studies in which subjects stood on force plates, aversive photographs induced attenuation of nondirectional movement in patients and controls. Regarding seated postural responses, controls leaned towards neutral photographs and away from aversive ones, while participants with PTSD did the opposite. Regulation had no impact on seated movement but was associated with a seated postural withdrawal from the computer screen.