title: Effects of predictability of shock timing and intensity on aversive responses.
abstract: An important characteristic of aversive stimuli that determines emotional responses is whether the stimuli are predictable. Human laboratory studies in this area have typically operationalized predictability as being able to predict the occurrence of aversive events, but animal studies suggest that being able to predict other characteristics of the stimuli may also play a role in aversive responding. To examine this, the present study examined two characteristics: the timing and intensity of aversive stimuli. Specifically, participants were randomly assigned to receive shocks that were either predictable or unpredictable in terms of when they would occur (timing) and/or their intensity. Indicators of aversive emotional responses were EMG startle responses and subjective anxiety ratings. Results revealed that aversive responding was elevated for unpredictable timing and intensity suggesting that the predictability of both characteristics play a role in aversive responding (though the effects for timing were stronger). In sum, the anxiogenic effects of unpredictability may generalize to situations beyond unpredictable timing.
authors.affiliation: University of Illinois at Chicago, Department of Psychology, 1007 W Harrison St, Chicago, IL 60607, United States. stewarts@uic.edu
authors.forename: Stewart A
authors.initials: SA
authors.lastname: Shankman
authors.forename: E Jenna
authors.initials: EJ
authors.lastname: Robison-Andrew
authors.forename: Brady D
authors.initials: BD
authors.lastname: Nelson
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Altman
authors.forename: Miranda L
authors.initials: ML
authors.lastname: Campbell
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000503:physiopathology; D055592:Biophysical Phenomena / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology; D004597:Electroshock / Q000009:adverse effects*; D004644:Emotions / Q000502:physiology*; D004924:Escape Reaction / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D013216:Reflex, Startle / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult