HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barde, L. H.F. Articles by Thompson-Schill, S. L. Search for Related Content PubMed PubMed Citation Articles by Barde, L. H.F. Articles by Thompson-Schill, S. L.

Models of Functional Organization of the Lateral Prefrontal Cortex in Verbal Working Memory: Evidence in Favor of the Process Model

University of Pennsylvania

Research on the functional organization of the lateral prefrontal cortex (PFC) in working memory continues to be fairly equivocal between two major frameworks: organization-by-process or organization-by-material. Although there is fairly strong evidence for organization-by-process models from event-related fMRI studies, some investigators argue that the nature of the stimulus material better defines the functional organization of the lateral PFC, particularly in more ventral regions (BA 47/45/44). Specifically, the anterior region of the ventrolateral PFC (BA 47/45) is hypothesized to subserve semantic processing while the posterior region (BA 44) may subserve phonological processing. In the current event-related fMRI study, we directly compared process-related versus material-related organizational principles in a verbal working memory task. Subjects performed a modified delayed response task in which they (1) retained a list of five words or five nonwords during the delay period ("maintenance"), or (2) performed a semantic (size reordering) or phonological (alphabetical reordering) task on the word or nonword lists, respectively ("manipulation"). We did not find evidence during the delay period of our task to support claims of anterior–posterior specializations in the ventrolateral PFC for semantic versus phonological processing. Subjects did, however, display greater neuronal activity during the delay period of manipulation trials than maintenance trials in both the dorsolateral PFC and posterior ventrolateral regions. These data are more consistent with the process model of the organization of lateral PFC in verbal working memory.

This article has been cited by other articles:

				J. Rissman, A. Gazzaley, and M. D'Esposito Dynamic Adjustments in Prefrontal, Hippocampal, and Inferior Temporal Interactions with Increasing Visual Working Memory Load Cereb Cortex, July 1, 2008; 18(7): 1618 - 1629. [Abstract] [Full Text] [PDF]

				R. S. Blumenfeld and C. Ranganath Prefrontal Cortex and Long-Term Memory Encoding: An Integrative Review of Findings from Neuropsychology and Neuroimaging Neuroscientist, June 1, 2007; 13(3): 280 - 291. [Abstract] [PDF]

				L. J. Murray and C. Ranganath The Dorsolateral Prefrontal Cortex Contributes to Successful Relational Memory Encoding J. Neurosci., May 16, 2007; 27(20): 5515 - 5522. [Abstract] [Full Text] [PDF]

				H. R. Snyder, K. Feigenson, and S. L. Thompson-Schill Prefrontal Cortical Response to Conflict during Semantic and Phonological Tasks. J. Cogn. Neurosci., May 1, 2007; 19(5): 761 - 775. [Abstract] [Full Text] [PDF]

				J. T. Devlin and K. E. Watkins Stimulating language: insights from TMS Brain, March 1, 2007; 130(3): 610 - 622. [Abstract] [Full Text] [PDF]

				R. S. Blumenfeld and C. Ranganath Dorsolateral Prefrontal Cortex Promotes Long-Term Memory Formation through Its Role in Working Memory Organization J. Neurosci., January 18, 2006; 26(3): 916 - 925. [Abstract] [Full Text] [PDF]

				P. M. Gough, A. C. Nobre, and J. T. Devlin Dissociating Linguistic Processes in the Left Inferior Frontal Cortex with Transcranial Magnetic Stimulation J. Neurosci., August 31, 2005; 25(35): 8010 - 8016. [Abstract] [Full Text] [PDF]

				U. Muller, E. Mottweiler, and P. Bublak Noradrenergic blockade and numeric working memory in humans J Psychopharmacol, January 1, 2005; 19(1): 21 - 28. [Abstract] [PDF]

				E. R. Cardillo, J. Aydelott, P. M. Matthews, and J. T. Devlin Left Inferior Prefrontal Cortex Activity Reflects Inhibitory Rather Than Facilitatory Priming J. Cogn. Neurosci., November 1, 2004; 16(9): 1552 - 1561. [Abstract] [Full Text] [PDF]

				J. T. Devlin, P. M. Matthews, and M. F. S. Rushworth Semantic Processing in the Left Inferior Prefrontal Cortex: A Combined Functional Magnetic Resonance Imaging and Transcranial Magnetic Stimulation Study J. Cogn. Neurosci., January 1, 2003; 15(1): 71 - 84. [Abstract] [Full Text] [PDF]