Ventromedial prefrontal cortex and the regulation of physiological arousal

Neuroimaging studies show a correlation between activity of the ventromedial prefrontal cortex (vmPFC) and skin conductance measurements. However, little is known whether this brain region plays a causal role in regulating physiological arousal. To address this question, we employed Granger causality analysis (GCA) to establish causality between cerebral blood oxygenation level-dependent and skin conductance signals in 24 healthy adults performing a cognitive task during functional magnetic resonance imaging. the results showed that activity of the vmPFC not only negatively correlated with skin conductance level (SCL) but also Granger caused SCL, thus establishing the direction of influence. Importantly, across participants, the strength of Granger causality was negatively correlated to phasic skin conductance responses elicited by external events during the behavioral task. in contrast, activity of the dorsal anterior cingulate cortex positively correlated with SCL but did not show a causal relationship in GCA. These new findings indicate that the vmPFC plays a causal role in regulating physiological arousal. Increased vmPFC activity leads to a decrease in skin conductance. the findings may also advance our understanding of dysfunctions of the vmPFC in mood and anxiety disorders that involve altered control of physiological arousal.National Institute of HealthTourette Syndrome AssociationWilliam O. Seery FoundationYale Cancer CenterYale Univ, Dept Psychiat, New Haven, CT 06519 USAYale Univ, Dept Med, New Haven, CT 06519 USAVA Connecticut Healthcare Syst, Dept Med, West Haven, CT 06516 USAUniversidade Federal de São Paulo, Dept Sci & Technol, São Paulo, BrazilBrown Univ, Dept Biostat, Providence, RI 02912 USABrown Univ, Ctr Stat Sci, Providence, RI 02912 USAYale Univ, Interdept Neurosci Program, New Haven, CT 06520 USAYale Univ, Dept Neurobiol, New Haven, CT 06520 USAUniversidade Federal de São Paulo, Dept Sci & Technol, São Paulo, BrazilNational Institute of Health: R01DA023248National Institute of Health: R21AA018004National Institute of Health: K02DA026990National Institute of Health: R03CA138121Web of Scienc