Mar 18

Decreased BOLD response in a bilateral premotor-occipital-parietal network during performance of a practiced serial interception sequence

Eric W. Gobel, Paul J. Reber; Northwestern University
Cognitive Neuroscience Society 2010 Annual Meeting, Montreal, QB. 19 April 2010.

Most well practiced perceptual-motor skills are composed of a learned sequence of movements that must be performed in a particular order with specific, precise timing. Neuroimaging was used to identify the sequence-specific changes in neural activity occurring as a result of experience. Participants initially practiced the Serial Interception Sequence Learning (SISL) task, which emphasizes precise timing of an interception response to a moving visual cue and allows for manipulation of inter-stimulus timing information. After implicitly learning an embedded 12-item repeating sequence, fMRI data were collected while participants performed four transfer conditions, which maintained either the ordinal sequence, the timing sequence, both sequences, or neither sequence. When either the order of actions or the timing intervals between actions was changed, performance dropped to a level equivalent to that of a completely novel sequence. Performance of the practiced sequence was correlated with decreased activity across a bilateral premotor-occipital-parietal network, reflecting sequence-specific facilitation of motor planning, visual motion processing, and spatial relationship analysis. These reductions were not associated with decreases in reaction time since learning in the SISL task is reflected in increased accuracy of interception responses. Maintaining only the timing sequence increased activity in the same network, which may reflect interference of the random ordinal information during a practiced temporal pattern. These results show tight integration of timing and order information in a learned sequence, associated with decreased activity in a distributed cortical network of brain regions involved in the task.

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