title: Developmental changes in autonomic responses are associated with future reward/punishment expectations: A study of sympathetic skin responses in the Markov decision task.
abstract: OBJECTIVE
  Autonomic nervous system activity is recognized as a major component of emotional responses. Future reward/punishment expectations depend upon the process of decision making in the frontal lobe, which is considered to play an important role in executive function. The aim of this study was to investigate the relationship between autonomic responses and decision making during reinforcement tasks using sympathetic skin responses (SSR).
  
  
  METHODS
  Nine adult and 9 juvenile (mean age, 10.2years) volunteers were enrolled in this study. SSRs were measured during the Markov decision task (MDT), which is a reinforcement task. In this task, subjects must endure a small immediate loss to ultimately get a large reward. The subjects had to undergo three sets of tests and their scores in these tests were assessed and evaluated.
  
  
  RESULTS
  All adults showed gradually increasing scores for the MDT from the first to third set. As the trial progressed from the first to second set in adults, SSR appearance ratios remarkably increased for both punishment and reward expectations. In comparison with adults, children showed decreasing scores from the first to second set. There were no significant inter-target differences in the SSR appearance ratio in the first and second set in children. In the third set, the SSR appearance ratio for reward expectations was higher than that in the neutral condition.
  
  
  CONCLUSIONS
  In reinforcement tasks, such as MDT, autonomic responses play an important role in decision making. We assume that SSRs are elicited during efficient decision making tasks associated with future reward/punishment expectations, which demonstrates the importance of autonomic function. In contrast, in children around the age of 10years, the autonomic system does not react as an organized response specific to reward/punishment expectations. This suggests the immaturity of the future reward/punishment expectations process in children.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Graduate School, University of Yamanashi, Japan; Department of Pediatrics, Yamanashi Prefectural Akebono Medical Welfare Center, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hosaka
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Graduate School, University of Yamanashi, Japan; Department of Pediatrics, Yamanashi Prefectural Akebono Medical Welfare Center, Japan.
authors.forename: Kakuro
authors.initials: K
authors.lastname: Aoyagi
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Graduate School, University of Yamanashi, Japan. Electronic address: yoshi3st@ncnp.go.jp.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kaga
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Graduate School, University of Yamanashi, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Kanemura
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Graduate School, University of Yamanashi, Japan.
authors.forename: Kanji
authors.initials: K
authors.lastname: Sugita
authors.affiliation: Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Aihara
mesh_terms: D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D001341:Autonomic Nervous System / Q000254:growth & development* / Q000502:physiology*; D002648:Child; D003657:Decision Making / Q000502:physiology*; D004644:Emotions / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011678:Punishment; D012201:Reward; D012879:Skin Physiological Phenomena
keywords: Autonomic responses; Markov decision task (MDT); Prefrontal cortex (PFC); Reward/punishment expectations; Sympathetic skin response (SSR)