Document Detail

Reduced blocking as a result of increasing the number of blocking cues.
MedLine Citation:
PMID:  18567269     Owner:  NLM     Status:  MEDLINE    
Weak behavioral control (blocking) occurs when a target stimulus (X) is paired with an outcome in the presence of a well-established signal for the outcome (i.e., a blocking stimulus). Conventional Pavlovian conditioning theories explain this effect by asserting that a discrepancy between expected and experienced outcomes is necessary for learning about X and that no such discrepancy exists in blocking situations. These theories anticipate that the effect of additional well-established signals for the unconditioned stimulus (US) should be additive. In two conditioned barpress suppression experiments using rats as subjects, the opposite result was observed. Experiment 1 provided evidence that blocking was reduced when two blocking stimuli were present during X-US pairings relative to when one blocking stimulus was present. Experiment 2 elaborated on the mechanisms underlying the observations in Experiment 1, while explaining the discrepancy between the results of Experiment 1 and prior reports of the additivity of blocking stimuli.
James E Witnauer; Gonzalo P Urcelay; Ralph R Miller
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Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Psychonomic bulletin & review     Volume:  15     ISSN:  1069-9384     ISO Abbreviation:  Psychon Bull Rev     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-06-23     Completed Date:  2008-10-03     Revised Date:  2014-09-19    
Medline Journal Info:
Nlm Unique ID:  9502924     Medline TA:  Psychon Bull Rev     Country:  United States    
Other Details:
Languages:  eng     Pagination:  651-5     Citation Subset:  IM    
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MeSH Terms
Behavior, Animal
Conditioning, Classical*
Form Perception
Random Allocation
Rats, Sprague-Dawley
Grant Support
33881//PHS HHS; R01 MH033881/MH/NIMH NIH HHS; R01 MH033881-27/MH/NIMH NIH HHS

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