Dissociation between implicit and explicit responses in postconditioning UCS revaluation after fear conditioning in humans. Behav Neurosci 2013 Jun;127(3):357-68
Date
06/05/2013Pubmed ID
23731073Pubmed Central ID
PMC3959889DOI
10.1037/a0032742Scopus ID
2-s2.0-84878785514 (requires institutional sign-in at Scopus site) 30 CitationsAbstract
The nature of the relationship between explicit and implicit learning is a topic of considerable debate. To investigate this relationship we conducted two experiments on postconditioning revaluation of the unconditional stimulus (UCS) in human fear conditioning. In Experiment 1, the intensity of the UCS was decreased after acquisition for one group (devaluation) and held constant for another group (control). A subsequent test revealed that even though both groups exhibited similar levels of UCS expectancy, the devaluation group had significantly smaller conditional skin conductance responses. The devaluation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. In Experiment 2, the value of the UCS was increased after acquisition for one group (inflation) and held constant for another group (control). Test performance revealed that UCS inflation did not alter expectancy ratings, but the inflation group exhibited larger learned skin conductance responses than the control group. The inflation effect was not explained by differences in the explicit estimates of UCS probability or explicit knowledge that the UCS intensity had changed. The SCR revaluation effect was not dependent on explicit memory processes in either experiment. In both experiments we found differences on an implicit measure of learning in the absence of changes in explicit measures. Together, the differences observed between expectancy measures and skin conductance support the idea that these responses might reflect different types of memory formed during the same training procedure and be supported by separate neural systems.
Author List
Schultz DH, Balderston NL, Geiger JA, Helmstetter FJAuthor
Fred Helmstetter PhD Professor in the Psychology / Neuroscience department at University of Wisconsin - MilwaukeeMESH terms used to index this publication - Major topics in bold
AdolescentAdult
Analysis of Variance
Association Learning
Awareness
Conditioning, Classical
Electric Stimulation
Fear
Galvanic Skin Response
Humans
Intention
Photic Stimulation
Psychophysics
Reaction Time
Young Adult
