Issues concerning relative speed of processing hypotheses, schizophrenic performance deficits, and prefrontal function: Comment on Schooler et al. (1997).

Cohen, Jonathan; Dunbar, Kevin O.; Barch, Deanna M.; Braver, Todd S.

doi:10.1037/0096-3445.126.1.37

Cited by 8 publications

(23 citation statements)

References 18 publications

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“…Deficits have been attributed to a failure in cognitive-control over the inhibition of irrelevant information in WM or the selection of responses at retrieval (e.g., 13–18). However, prior approaches to studying WM in SZ have employed tasks requiring multiple cognitive-control processes that are challenging to disentangle, making it difficult to determine which specific component processes are impaired (16, 19–25). …”

Section: Introductionmentioning

confidence: 99%

Neural Correlates of Impaired Cognitive Control over Working Memory in Schizophrenia

Eich

Nee

Insel

et al. 2014

Biological Psychiatry

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Background One of the most common deficits in patients with schizophrenia (SZ) is in working memory (WM), which has wide-reaching impacts across cognition. However, prior approaches to studying WM in SZ have employed tasks that require multiple cognitive-control processes, making it difficult to determine which specific cognitive and neural processes underlie the WM impairment. Methods We used fMRI to investigate component processes of WM in SZ. Eighteen healthy controls (HCs) and 18 patients with SZ performed an item-recognition task that permitted separate neural assessments of 1) WM maintenance, 2) inhibition, and 3) interference-control in response to recognition probes. Results Prior to inhibitory demands, posterior ventrolateral prefrontal cortex (VLPFC), an area involved in WM maintenance, was activated to a similar degree in both HCs and patients, indicating preserved maintenance operations in SZ. When cued to inhibit items from WM, HCs showed reduced activation in posterior VLPFC, commensurate with appropriately inhibiting items from WM. However, these inhibition-related reductions were absent in patients. When later probed with items that should have been inhibited, patients showed reduced behavioral performance and increased activation in mid-VLPFC, an area implicated in interference-control. A mediation analysis indicated that impaired inhibition led to increased reliance on interference-control and reduced behavioral performance. Conclusions In SZ, impaired control over memory, manifested through proactive inhibitory deficits, leads to increased reliance on reactive interference-control processes. The strain on interference-control processes results in reduced behavioral performance. Thus, inhibitory deficits in SZ may underlie widespread impairments in WM and cognition.

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Section: Introductionmentioning

confidence: 99%

Neural Correlates of Impaired Cognitive Control over Working Memory in Schizophrenia

Eich

Nee

Insel

et al. 2014

Biological Psychiatry

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“…This structure is involved in important brain functions such as spatial memory (e.g., Gaffan 1994; Parker and Gaffan 1997), memory retrieval (e.g., Calabrese et al, 1995), and verbal memory (e.g., Calabrese et al, 1995; Mc Mackin et al, 1995). These are also all functions disturbed in schizophrenia, including spatial memory (e.g., Park and Holzman,1992; Carter et al, 1996 and Park et al, 1999) memory retrieval (e.g., Anderson and Spellman, 1995) and verbal memory (e.g., Park and Holzman,1992; Carter et al, 1998; Cohen et al, 1997; Callicott et al, 2000; Perlstein et al, 2001). Thus characterizing disruptions in fornix integrity might further our understanding of this disorder.…”

Section: Introductionmentioning

confidence: 99%

Diffusion tractography of the fornix in schizophrenia

Fitzsimmons

Kubicki

Smith

et al. 2009

Schizophrenia Research

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Background-White matter fiber tracts, especially those interconnecting the frontal and temporal lobes, are likely implicated in pathophysiology of schizophrenia. Very few studies, however, have focused on the fornix, a compact bundle of white matter fibers, projecting from the hippocampus to the septum, anterior nucleus of the thalamus and the mamillary bodies. Diffusion Tensor Imaging (DTI), and a new post-processing method, fiber tractography, provides a unique opportunity to visualize and to quantify entire trajectories of fiber bundles, such as the fornix, in vivo. We applied these techniques to quantify fornix diffusion anisotropy in schizophrenia.

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“…Processing speed and WM are integral to a variety of cognitive functions and there is mounting evidence that decrements in these two areas occur almost universally in neurologically impaired populations. For example, both WM and processing speed deficits have been noted after brain trauma (TBI) [McDowell et al,1997; Stuss et al,1985] multiple sclerosis [Demaree et al,1999; Mostofsky et al,2003; Rao et al,1989a; Rao et al,1989b], schizophrenia [Cohen et al,1997; Saykin et al,1991,1994], dementia [Bradley et al,1989; Collette et al,1999; Morris and Baddeley,1988] and normal aging [Salthouse,1992,1996; Salthouse and Coon,1993]. Moreover, processing speed has been shown to account for significant variance in the other cognitive deficits observed in clinical populations [Archibald and Fisk,2000; DeLuca et al,2004; Demaree et al,1999; Kail,1998; Li et al,2004; Litvan et al,1988].…”

Section: Introductionmentioning

confidence: 99%

Prefrontal modulation of working memory performance in brain injury and disease

Hillary

Genova

Chiaravalloti

et al. 2006

Human Brain Mapping

110

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The inter-related cognitive constructs of working memory (WM) and processing speed are fundamental components to general intellectual functioning in humans. Importantly, both WM and processing speed are highly susceptible to disruption in cases of brain injury, neurologic illness, and even in normal aging. A goal of this article is to summarize and critique the functional imaging studies of speeded working memory in neurologically impaired populations. This review focuses specifically on the role of the lateral prefrontal cortex in mediating WM performance and integrates the relevant WM literature in healthy adults with the current findings in the clinical literature. One important finding emerging from a summary of this literature is the dissociable contributions made by ventrolateral and dorsolateral prefrontal cortex (VLPFC and DLPFC) in guiding performance on tasks of WM. Throughout this review, it is shown that when cerebral resources are challenged, it is DLPFC, and often right DLPFC specifically, that plays a critical role in modulating WM functioning. In addition, this article will examine the relationship between task performance and brain activation across studies to clarify the role of increased DLPFC activity in clinical samples. Finally, explanations are offered for the observed increased DLPFC activation and the potentially unique role of right DLPFC in mediating WM performance during periods of cerebral challenge.

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Issues concerning relative speed of processing hypotheses, schizophrenic performance deficits, and prefrontal function: Comment on Schooler et al. (1997).

Cited by 8 publications

References 18 publications

Neural Correlates of Impaired Cognitive Control over Working Memory in Schizophrenia

Neural Correlates of Impaired Cognitive Control over Working Memory in Schizophrenia

Diffusion tractography of the fornix in schizophrenia

Prefrontal modulation of working memory performance in brain injury and disease

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