Dissociation of physiology and behavior in PTSD

J. H. Casada, J. D. Roache

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


We have previously reported that subjects with posttraumatic stress disorder (PTSD) differ from trauma controls in their ability to produce and withhold responses in the Stop-Signal Task depending on the motivational context as determined by financial reward. This experiment measured skin conductance and heart rate to assess autonomic changes accompanying these different patterns of behavior. Fowles hypothesized that heart rate would increase with behavioral activation and that increases in skin conductance would accompany behavioral inhibition. Both PTSD and comparison groups showed the expected behavioral changes in response to rewards, but they differed in their physiological responses. The subjects in the traumatized comparison group showed changes in skin conductance and heart rate consistent with Fowles' hypothesis and the observed changes in behavioral inhibition and activation. However, PTSD subjects showed no significant change in either physiological measure. These results demonstrate a dissociation between autonomic reactivity and motivated behavior in PTSD that may represent one aspect of emotional numbing.

Original languageEnglish (US)
Pages (from-to)243-248
Number of pages6
JournalInternational Journal of Psychophysiology
Issue number2
StatePublished - Nov 2006


  • Heart rate
  • Inhibition
  • PTSD
  • Skin conductance
  • Trauma

ASJC Scopus subject areas

  • Neuroscience(all)
  • Neuropsychology and Physiological Psychology
  • Physiology (medical)


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