Document Detail

Reaction times identify a Pavlovian component in a two-choice discrimination.
MedLine Citation:
PMID:  19429212     Owner:  NLM     Status:  MEDLINE    
Six pigeons discriminated on discrete trials between two colors. In Experiment 1, two luminous spots were both either blue or green and the reinforced responses were "peck left" for blue and "peck right" for green. In Experiment 2, the hue of a center spot controlled subsequent choice pecks to left or right. In both experiments response bias was manipulated in two ways. During stimulus frequency ("SF") sessions correct responses brought food on 40% of trials; in "imbalanced" blocks of sessions one hue appeared on 80% of trials and the other on 20%. During reinforcement probability ("RNF") sessions the hues appeared equally often, but in imbalanced blocks the hues signaled different reinforcement probabilities, either 64% or 16%. In "balanced" control blocks the hues appeared equally often and were both reinforced at 40%. The experiments gave similar results. When bias was computed from choice percentages the imbalanced conditions yielded substantial response bias, and the amount of bias was about the same under RNF and SF treatments. However, reaction times (RTs) gave a different outcome. RNF imbalance slowed responses directed at the less reinforced stimulus, but SF imbalance had little RT effect (Experiment 1) or no effect (Experiment 2). These results suggest that choice was controlled by an instrumental stimulus-response-reinforcement association, whereas RTs were controlled by a Pavlovian stimulus-reinforcement association.
Donald S Blough
Publication Detail:
Type:  Journal Article     Date:  2009-02-03
Journal Detail:
Title:  Behavioural processes     Volume:  81     ISSN:  1872-8308     ISO Abbreviation:  Behav. Processes     Publication Date:  2009 Jun 
Date Detail:
Created Date:  2009-05-11     Completed Date:  2009-07-15     Revised Date:  2013-06-02    
Medline Journal Info:
Nlm Unique ID:  7703854     Medline TA:  Behav Processes     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  195-204     Citation Subset:  IM    
Brown University, Walter S. Hunter Laboratory of Psychology, Providence, RI 02912, USA.
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MeSH Terms
Choice Behavior / physiology*
Conditioning, Classical / physiology*
Data Interpretation, Statistical
Discrimination (Psychology) / physiology*
Discrimination Learning / physiology*
Photic Stimulation
Psychomotor Performance / physiology
Reaction Time / physiology*
Reinforcement Schedule
Grant Support
R01 MH061782-09/MH/NIMH NIH HHS

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