title: Barratt Impulsivity and Neural Regulation of Physiological Arousal.
abstract: BACKGROUND
  Theories of personality have posited an increased arousal response to external stimulation in impulsive individuals. However, there is a dearth of studies addressing the neural basis of this association.
  
  
  METHODS
  We recorded skin conductance in 26 individuals who were assessed with Barratt Impulsivity Scale (BIS-11) and performed a stop signal task during functional magnetic resonance imaging. Imaging data were processed and modeled with Statistical Parametric Mapping. We used linear regressions to examine correlations between impulsivity and skin conductance response (SCR) to salient events, identify the neural substrates of arousal regulation, and examine the relationship between the regulatory mechanism and impulsivity.
  
  
  RESULTS
  Across subjects, higher impulsivity is associated with greater SCR to stop trials. Activity of the ventromedial prefrontal cortex (vmPFC) negatively correlated to and Granger caused skin conductance time course. Furthermore, higher impulsivity is associated with a lesser strength of Granger causality of vmPFC activity on skin conductance, consistent with diminished control of physiological arousal to external stimulation. When men (n = 14) and women (n = 12) were examined separately, however, there was evidence suggesting association between impulsivity and vmPFC regulation of arousal only in women.
  
  
  CONCLUSIONS
  Together, these findings confirmed the link between Barratt impulsivity and heightened arousal to salient stimuli in both genders and suggested the neural bases of altered regulation of arousal in impulsive women. More research is needed to explore the neural processes of arousal regulation in impulsive individuals and in clinical conditions that implicate poor impulse control.
authors.affiliation: Department of Psychiatry, Yale University, New Haven, CT 06519, United States of America.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Psychiatry, Yale University, New Haven, CT 06519, United States of America.
authors.forename: Sien
authors.initials: S
authors.lastname: Hu
authors.affiliation: Department of Psychiatry, Yale University, New Haven, CT 06519, United States of America; Department of Psychology, South China Normal University, Guangzhou, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Psychiatry, Yale University, New Haven, CT 06519, United States of America; Department of Psychiatry, China Medical University, Tai-Chung, Taiwan.
authors.forename: Po-Lun
authors.initials: PL
authors.lastname: Wu
authors.affiliation: Department of Medicine, Yale University, New Haven, CT 06519, United States of America; Department of Medicine, VA Connecticut Healthcare Systems, West Haven, CT 06516, United States of America.
authors.forename: Herta H
authors.initials: HH
authors.lastname: Chao
authors.affiliation: Department of Psychiatry, Yale University, New Haven, CT 06519, United States of America; Interdepartmental Neuroscience Program, Yale University, New Haven, CT 06520, United States of America; Department of Neurobiology, Yale University, New Haven, CT 06520, United States of America.
authors.forename: Chiang-shan R
authors.initials: CS
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D001143:Arousal; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007175:Impulsive Behavior; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000502:physiology*; D012879:Skin Physiological Phenomena; D055815:Young Adult