Physiological Correlates of Sluggish Cognitive Tempo in Children: Examining Autonomic Nervous System Reactivity during Social and Cognitive Stressor Tasks.

It is important to establish correlates of sluggish cognitive tempo (SCT) across units of analysis and to better understand how SCT may be conceptualized in models of psychopathology. The current study examined SCT symptoms in relation to automatic nervous system reactivity during social and cognitive stressor tasks. Participants were 61 children ages 8-12 years with a full range of attention-deficit/hyperactivity disorder (ADHD) symptom severity. Parents provided ratings of SCT and parents and teachers completed measures that were used to create composite indices of ADHD symptoms. Children were administered standardized peer rejection and impossible puzzle tasks, during which their respiratory sinus arrhythmia (RSA) and skin conductance level (SCL) reactivity were recorded. Regression analyses indicated that SCT symptoms were unassociated with RSA reactivity to either task. Greater SCT symptoms were significantly associated with greater SCL reactivity to peer rejection. Greater SCT symptoms were not significantly associated with SCL reactivity to the impossible puzzle task. The pattern of findings was unchanged in sensitivity analyses that controlled for ADHD symptoms, internalizing symptoms, medication status, or sex. This study provides the first evidence that SCT symptoms are associated with sympathetic nervous system reactivity. These findings suggest that SCT symptoms may be associated with greater behavioral inhibition system activation, and reactivity may be especially pronounced in social challenges.