Functional MRI studies of spatial and nonspatial working memory

D’Esposito, Mark; Aguirre, Geoffrey K.; Zarahn, Eric; Ballard, Dana H.; Shin, Robert K.; Lease, J.

doi:10.1016/s0926-6410(98)00004-4

Cited by 891 publications

(623 citation statements)

References 84 publications

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“…Yet, other areas including the dorsal premotor regions in the superior frontal sulcus and posterior parietal regions were active during the delay, congruent with arguably the most consistent finding among neuroimaging studies of working memory (e.g. [23,49,50]). The authors concluded that the DLPFC does not store active representations of the items; it selects the appropriate memory-guided response.…”

Section: Processes That Support Maintenance Selection Processessupporting

confidence: 76%

Persistent activity in the prefrontal cortex during working memory

Curtis

D’Esposito

2003

Trends in Cognitive Sciences

1,691

101

1,184

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The dorsolateral prefrontal cortex (DLPFC) plays a crucial role in working memory. Notably, persistent activity in the DLPFC is often observed during the retention interval of delayed response tasks. The code carried by the persistent activity remains unclear, however. We critically evaluate how well recent findings from functional magnetic resonance imaging studies are compatible with current models of the role of the DLFPC in working memory. These new findings suggest that the DLPFC aids in the maintenance of information by directing attention to internal representations of sensory stimuli and motor plans that are stored in more posterior regions.Working memory refers to the temporary representation of information that was just experienced or just retrieved from long-term memory. These active representations are short-lived, but can be maintained for longer periods of time through active rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goaldirected behavior. Most definitions of working memory include both storage and (executive) control components [1]. Cognitive neuroscientists are searching for ways to disassociate the separate components of working memory in attempts to localize and clearly characterize their neural implementation. The prefrontal cortex (PFC) is thought to be the most important substrate for working memory (Fig. 1). Two key findings from studies of monkeys performing delayed response tasks suggest a crucial role for the PFC in working memory. First, experimental lesions of the principal sulcus in the dorsolateral prefrontal cortex (DLPFC) cause delay-dependent impairments [2][3][4]. That is, forgetting increases not only when a delay is imposed but increases with the length of the delay. Second, neurophysiological unit recordings from the DLPFC often show persistent, sustained levels of neuronal firing during the retention interval of delayed response Fig. 1. Lateral surface of (a) macaque and (b) human brain. The PFC is composed of lateral, medial, and orbital sectors that are believed to be functionally distinct given the selective effects of damage and distribution of afferent and efferent projections. The tinted areas correspond to those defined by Petrides and Pandya [71] based on cytoarchitecture and connectivity. Notably, the mid-DLPFC comprises areas 46 and 9/46 and the mid-VLPFC comprises areas 45 and 47/12. Note that much of area 46 lies in the depths of the principle sulcus of the monkey and the intermediate frontal sulcus of the human. Frontal premotor regions are also highlighted. The frontal eye field (F) in the macaque lies in the anterior bank of the arcuate sulcus in area 8A. In the human, F is found in the vicinity of the precentral sulcus and superior frontal sulcus junction (area 6 and maybe the caudal-most portion of 8A). The frontal eye field is a premotor region involved in the control of eye movements. Broca's area (B, area 44) is also a premotor area that is involved in the product...

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Section: Processes That Support Maintenance Selection Processessupporting

confidence: 76%

Persistent activity in the prefrontal cortex during working memory

Curtis

D’Esposito

2003

Trends in Cognitive Sciences

1,691

101

1,184

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“…According to the model, ventrolateral prefrontal cortex (PFC; Brodmann's area [BA] 44, 45, and 47) is responsible for maintenance of information in the visuospatial and phonological stores, and dorsolateral PFC (BA 9 and 46) is required for CES processes of monitoring and manipulation (Petrides, 1994). This model is broadly supported by reviews of human imaging studies of working memory (D'Esposito et al, 1998;Owen, 1997). These studies contrast specific functions (e.g., maintenance vs. maintenance plus monitoring and manipulation) and generally find that ventrolateral PFC mediates maintenance of verbal and non-verbal information and that dorsolateral PFC is involved in executive components of monitoring and manipulation (Berman, Austin-Lane, Esposito, Van Horn, & Weinberger, 1996;Klingberg, O'Sullivan, & Roland, 1997;Manoach et al, 1997;Salmon et al, 1996;Stern et al, 2000;Tsukiura et al, 2001).…”

Section: Nih-pa Author Manuscriptmentioning

confidence: 83%

“…Support of domain specificity from the human neuroimaging literature has been inconsistent. Although several studies found prefrontal regions that were differentially activated by working memory for faces versus spatial locations (Courtney, Ungerleider, Keil, & Haxby, 1996;Ungerleider, Courtney, & Haxby, 1998), there was substantial functional overlap (Haxby, Petit, Ungerleider, & Courtney, 2000), and several recent reviews and meta-analyses failed to support domain specificity for dorsal versus ventral aspects of the PFC (D'Esposito et al, 1998;Owen, 1997).Because the fractal n-back task is a measure of object identification (what) rather than of spatial localization (where), the current study could not test domain specificity models of dorsal versus ventral PFC function. However, the current paradigm could test a variant of (Awh et al, 1996;Jonides et al, 1993;Smith et al, 1996).…”

mentioning

confidence: 99%

“…A right-left face versus name dissociation was found only for unfamous faces, leading the investigators to speculate that previous knowledge of famous faces was more likely to invoke both verbal and nonspatial visual processing. Finally, a quantitative review of the literature (D'Esposito et al, 1998) concluded that hemispheric asymmetries might be restricted to ventrolateral PFC rather than dorsolateral PFC.The n-back paradigm is well suited to study both process-specific and domain-specific aspects of the neural correlates of working memory (Awh et al, 1996;Braver et al, 1997;Cohen et al, 1997;Nystrom et al, 2000;Postle, Stern, Rosen, & Corkin, 2000;Smith et al, 1996). During n-back tasks, participants view a continuous sequence of stimuli, and for each stimulus, the participants decide whether it matches the stimulus they saw (n stimuli) earlier.…”

mentioning

confidence: 99%

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Working memory for complex figures: An fMRI comparison of letter and fractal n-back tasks.

Ragland¹,

Turetsky²,

Gur³

et al. 2002

Neuropsychology

264

186

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Abstractn -back letter and fractal tasks were administered to 11 participants during functional magnetic resonance imaging to test process specificity theories of prefrontal cortex (PFC) function and assess task validity. Tasks were matched on accuracy, but fractal n-back responses were slower and more conservative. Maintenance (1-back minus 0-back) activated inferior parietal and dorsolateral PFC, with additional activation in right ventrolateral PFC during letter n-back and left lingual gyrus during fractal n-back. Maintenance plus manipulation (2-back minus 0-back) activated inferior parietal, Broca's area, insula, and dorsolateral and ventral PFC, with greater right dorsolateral PFC activation for letter n-back. Manipulation only (2-back minus 1-back) produced additional and equivalent dorsolateral PFC and anterior cingulate activation in both tasks. Results support fractal n-back validity and indicate substantial overlap in working memory functions of dorsal and ventral PFC.Working memory refers to a limited capacity system responsible for temporary maintenance and online manipulation of information required for guidance of subsequent behavior. Working memory is conceptualized as having several components including a central executive system (CES) and two modality-specific slave systems: the visuospatial sketch pad and the phonological loop (Baddeley, 1986(Baddeley, , 1992Baddeley & Hitch, 1974). The CES allocates attentional resources and is responsible for coordination of top-down processes permitting monitoring and manipulation of information within the short-term store (e.g., temporal sequencing). The visuospatial sketch pad maintains visuospatial information in a temporary visuospatial store, and the phonological loop maintains verbal material in a phonological store through an articulatory rehearsal process. Much of the research on working memory has focused on anatomically dissociating these multiple processes. The goal of the current functional magnetic resonance imaging (fMRI) study is to use a parametric n-back paradigm (Awh et al., 1996;Braver et al., 1997;Cohen et al., 1994Cohen et al., , 1997Gervins & Cutillo, 1993; to contrast the effect of working memory load on regional brain function during a standard letter n-back task versus an nback task using complex geometric objects that have not been previously studied. NIH Public Access Author ManuscriptNeuropsychology. Author manuscript; available in PMC 2015 February 18. Published in final edited form as:Neuropsychology. 2002 July ; 16(3): 370-379. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptDemonstrating similar effects of working memory load on the two tasks provides initial evidence for the construct validity of the new task.The process specificity model attempts to parse prefrontal regions mediating different components of working memory. According to the model, ventrolateral prefrontal cortex (PFC; Brodmann's area [BA] 44, 45, and 47) is responsible for maintenance of information in the visuospatial and phonolog...

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“…Alternatively, another model of prefrontal organization (DÕEsposito et al, 1998;Owen et al, 1998;Petrides, 1996;Postle, Berger, & DÕEsposito, 1999) suggests a subdivision of the prefrontal cortex depending rather upon the type of processing than on the informational domain. According to this model, monitoring and manipulation of information within working memory depend on the mid-dorsolateral frontal cortex, whereas maintenance of information involves the mid-ventrolateral and -dorsolateral frontal cortex (Postle et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

Processing of temporal duration information in working memory after frontodorsal tumour excisions

Hälbig

Cramon

Schmid

et al. 2002

Brain and Cognition

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This study aimed to test the hypothesis that impairments of temporal duration processing after frontal lobe lesions reflect deficits in executive monitoring functions rather than a domain-specific deficit in the maintenance of duration information in working memory. Patients with frontodorsal lesions, clinical controls with post-central lesions, and healthy controls performed recognition and classification tasks, which should allow for testing maintenance and monitoring functions, respectively. Results showed mild non-selective impairments of the frontal patients on both temporal and spatial recognition tasks, but a marked selective degradation on temporal classification while performance on spatial classification was unimpaired. This suggests that maintenance of duration information in working memory after frontal lesions is basically preserved but that, depending on executive task characteristics, there is a specific deficit in the strategic organization of this type of information.

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Functional MRI studies of spatial and nonspatial working memory

Cited by 891 publications

References 84 publications

Persistent activity in the prefrontal cortex during working memory

Persistent activity in the prefrontal cortex during working memory

Working memory for complex figures: An fMRI comparison of letter and fractal n-back tasks.

Processing of temporal duration information in working memory after frontodorsal tumour excisions

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