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

Abstract

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 (RAMP) paradigm, can yield reliable measures of individual sensorimotor control performance. This study used this paradigm to investigate control deficits in PTSD relative to both healthy volunteer and a non-PTSD psychiatric comparison group.

Methods: We examined control processing using the RAMP paradigm in a sample of 40 individuals with PTSD, along with matched groups of 40 individuals with mood and anxiety (MA) complaints and 40 healthy controls (HC). We estimated K_p (drive) and K_d (damping) parameters using a proportion-derivative (PD) control modeling approach.

Results: The K_p parameter was lower in the PTSD group compared to the HC (Cohen's d = .86) and MA groups (Cohen's d = 0.63). After controlling for color-word inhibition, K_p remained lower in the PTSD group versus HC (Cohen's d = 0.79) and versus MA (Cohen's d = 0.62). 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 mediated by K_d.

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