title: Exteroceptive suppression of temporalis muscle activity in subjects with high and low aggression traits.
abstract: OBJECTIVE
  There is evidence that the second exteroceptive suppression period of temporalis muscle activity (ES2) is modulated by the 5-HT neuronal activity in the brainstem, and the aggression trait is also connected with the cerebral 5-HT neuronal innervation. We therefore studied the temporalis ES2 in subjects with high and low aggression traits.
  
  
  METHODS
  Sixty-five subjects with either low or high aggression trends, judged by clinical interview, answered the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ), the Zuckerman Sensation Seeking Scales (SSS) and the Plutchik-van Praag Depression Inventory (PVP). These also underwent a temporalis ES2 test procedure. Twenty-two subjects with a high ZKPQ aggression trait score and 27 with a low score were selected for data analysis.
  
  
  RESULTS
  On average, the high aggression group displayed significantly reduced temporalis ES2 duration, elevated ZKPQ Impulsive Sensation Seeking, Neuroticism-Anxiety and Aggression-Hostility, and PVP scores. The personality traits were not related with either latency or duration of temporalis ES2 in any group. The PVP score, however, was negatively correlated with ES2 duration in all 49 subjects.
  
  
  CONCLUSIONS
  This study demonstrates neurophysiologic signs of brainstem dysfunction in subjects with high aggression traits.
authors.affiliation: Center of Psychotherapy, Department of Clinical Psychology, Zhejiang University School of Medicine, Yan'an Road 353, 310031 Hangzhou, Zhejiang, China. wangmufan@msn.com
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Sun
authors.forename: Xujun
authors.initials: X
authors.lastname: Ye
authors.forename: Mowei
authors.initials: M
authors.lastname: Shen
authors.forename: Rui
authors.initials: R
authors.lastname: Zhu
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000328:Adult; D000374:Aggression / Q000502:physiology*; D003863:Depression / Q000523:psychology; D004576:Electromyography; D005106:Exploratory Behavior; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D009483:Neuropsychological Tests; D010556:Personality Tests; D012701:Serotonin / Q000502:physiology
chemical_list: D012701:Serotonin