Dorsolateral prefrontal contributions to human working memory

Abstract

Although neuroscience has made remarkable progress in understanding the involvement of prefrontal cortex (PFC) in human memory, the necessity of dorsolateral PFC (dlPFC) for key competencies of working memory remains largely unexplored. We therefore studied human brain lesion patients to determine whether dlPFC is necessary for working memory function, administering subtests of the Wechsler Memory Scale, the Wechsler Adult Intelligence Scale, and the N-Back Task to three participant groups: dlPFC lesions (n=19), non-dlPFC lesions (n=152), and no brain lesions (n=54). DlPFC damage was associated with deficits in the manipulation of verbal and spatial knowledge, with left dlPFC necessary for manipulating information in working memory and right dlPFC critical for manipulating information in a broader range of reasoning contexts. Our findings elucidate the architecture of working memory, providing key neuropsychological evidence for the necessity of dlPFC in the manipulation of verbal and spatial knowledge.

Copyright © 2012 Elsevier Ltd. All rights reserved.

Figures

Figure 1

Diagram of the lesion overlap map for the dorsolateral prefrontal patients. The color indicates the number of veterans in the left dorsolateral prefrontal group (n = 19) with damage to a given voxel. The greatest lesion overlap (red) occurred in the dorsolateral prefrontal cortex (BA 9). The depicted sagittal slices progress from the midline (top left) to lateral regions of the left hemisphere (bottom right).

Figure 2

Diagram of the lesion overlap map for the left dorsolateral prefrontal patients. The color indicates the number of veterans in the left dorsolateral prefrontal group (n = 7) with damage to a given voxel. The greatest lesion overlap (red) occurred in the dorsolateral prefrontal cortex (BA 9). The depicted sagittal slices progress from the midline (top left) to lateral regions of the left hemisphere (bottom right).

Figure 3

Diagram of the lesion overlap map for the right dorsolateral prefrontal patients. The color indicates the number of veterans in the right dorsolateral prefrontal group (n = 9) with damage to a given voxel. The greatest lesion overlap (red) occurred in the dorsolateral prefrontal cortex (BA 9). The illustrated sagittal slices progress from the midline (top left) to lateral regions of the right hemisphere (bottom right).

Figure 4

Lesion diagram of the (a) left and (b) right dorsolateral prefrontal patients illustrating the overlap with the peak activation reported in the Wager and Smith (2003) meta-analysis (in blue).