Sensorimotor Feedback Control Dysfunction as a Marker of Posttraumatic Stress Disorder.

Background: Posttraumatic stress disorder (PTSD) is characterized not only by its direct association with traumatic events but also by a potential deficit in inhibitory control across emotional, cognitive, and sensorimotor domains. Recent research has shown that a continuous sensorimotor feedback control task, the rapid assessment of motor processing paradigm, can yield reliable measures of individual sensorimotor control performance. This study used this paradigm to investigate control deficits in PTSD compared with both a healthy volunteer group and a non-PTSD psychiatric comparison group.

Methods: We examined control processing using the rapid assessment of motor processing paradigm in a sample of 40 individuals with PTSD, matched groups of 40 individuals with mood and anxiety complaints, and 40 healthy control participants. We estimated K_p (drive) and K_d (damping) parameters using a proportional-derivative control modeling approach.

Results: The K_p parameter was lower in the PTSD group than in the healthy control (Cohen's d = 0.86) and mood and anxiety (Cohen's d = 0.63) groups. After controlling for color-word inhibition, K_p remained lower in the PTSD group than in the healthy control (Cohen's d = 0.79) and mood and anxiety (Cohen's d = 0.62) groups. Mediation analysis showed that K_d significantly mediated the relationship between PTSD and control deficits in the K_p parameter, with 96% of the effect being mediated by K_d.

Conclusions: These findings underscore the potential of using dynamic control paradigms to elucidate the control dysfunctions in PTSD and suggest that different psychiatric conditions may distinctly influence subcomponents of sensorimotor control.