Journal of the International Neuropsychological Society

Table of Contents - 2006 - Volume 12, Issue 02  


SYMPOSIUM

Is the Prefrontal Cortex Necessary for Delay Task Performance? Evidence from Lesion and fMRI Data

MARK  D'ESPOSITO  a1 c1 , JEFFREY W.  COONEY  a1 , ADAM  GAZZALEY  a1 , SASHA E.B.  GIBBS  a1 and BRADLEY R.  POSTLE  a2
a1 Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California
a2 Department of Psychology, University of Wisconsin-Madison, Madison, Wisconsin

Article author query
d;esposito m   [PubMed][Google Scholar] 
cooney jw   [PubMed][Google Scholar] 
gazzaley a   [PubMed][Google Scholar] 
gibbs seb   [PubMed][Google Scholar] 
postle br   [PubMed][Google Scholar] 

Abstract

Although the prefrontal cortex (PFC) is consistently found to be associated with various working memory processes, the necessity of the PFC for such processes remains unclear. To elucidate PFC contributions to storage and rehearsal/maintenance processes engaged during verbal working memory function, we assessed behavior of patients with lesions to the left or right lateral PFC, and neural activity of healthy young subjects during fMRI scanning, during performance of working memory tasks. We found that PFC lesions did not affect storage processes—which is consistent with the notion that posterior cortical networks can support simple retention of information. We also found that PFC lesions did not affect rehearsal/maintenance processes, which was in contrast to our finding that healthy subjects performing a verbal delayed recognition task showed bilateral PFC activation. These combined imaging and behavioral data suggest that working memory rehearsal/maintenance processes may depend on both hemispheres, which may have implications for recovery of function and development of rehabilitation therapies after frontal injury. (JINS, 2006, 12, 248–260.)

(Received March 1 2005)
(Revised October 20 2005)
(Accepted October 24 2005)


Key Words: Short-term memory; Delayed-recall task; Delayed-recognition task; Frontal lobe; Cognition; Stroke; fMRI.

Correspondence:
c1 Reprint request to: Mark D'Esposito, MD, Helen Wills Neuroscience Institute, University of California, 132 Barker Hall, Berkeley, CA 94720-3190. E-mail: despo@berkeley.edu

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