Citation

Casada JH, Roache JD. Int. J. Psychophysiol. 2006; 62(2): 243-248.

Affiliation

University of Texas Health Science Center at San Antonio, TX, USA. casada@uthscsa.edu

Copyright

(Copyright © 2006, Elsevier Publishing)

DOI

10.1016/j.ijpsycho.2006.04.005

PMID

16814888

Abstract

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.

Language: en