Document Detail


Changing the "when" and "what" of intended actions.
MedLine Citation:
PMID:  19710381     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Humans often have to modify the timing and/or type of their planned actions on the basis of new sensory information. In the present experiments, participants planned to make a right index finger keypress 3 s after a warning stimulus but on some trials were interrupted by a temporally unpredictable auditory tone prompting the same action (experiment 1) or a different action (experiment 2). In experiment 1, by comparing the reaction time (RT) to tones presented at different stages of the preparatory period to RT in a simple reaction time condition, we determined the cost of switching from an internally generated mode of response production to an externally triggered mode in situations requiring only a change in when an action is made (i.e., when the tone prompts the action at a different time from the intended time of action). Results showed that the cost occurred for interruption tones delivered 200 ms after a warning stimulus and remained relatively stable throughout most of the preparatory period with a reduction in the magnitude of the cost during the last 200 ms prior to the intended time of movement. In experiment 2, which included conditions requiring a change in both when and what action is produced on the tone, results show a larger cost when the switched to action is different from the action being prepared. We discuss our results in the light of neurophysiological experiments on motor preparation and suggest that intending to act is accompanied by a general inhibitory mechanism preventing premature motor output and a specific excitatory process pertaining to the intended movement. Interactions between these two mechanisms could account for our behavioral results.
Authors:
Sukhvinder S Obhi; Shannon Matkovich; Robert Chen
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-08-26
Journal Detail:
Title:  Journal of neurophysiology     Volume:  102     ISSN:  1522-1598     ISO Abbreviation:  J. Neurophysiol.     Publication Date:  2009 Nov 
Date Detail:
Created Date:  2009-11-05     Completed Date:  2010-01-25     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0375404     Medline TA:  J Neurophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2755-62     Citation Subset:  IM    
Affiliation:
Centre for Cognitive Neuroscience and Wilfrid Laurier University, Waterloo, Ontario, Canada. sobhi@wlu.ca
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MeSH Terms
Descriptor/Qualifier:
Acoustic Stimulation / methods
Adult
Attention / physiology
Cognition / physiology*
Female
Fingers / physiology
Humans
Intention*
Judgment / physiology
Male
Movement / physiology*
Psychomotor Performance / physiology*
Reaction Time / physiology
Time Factors
Young Adult

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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