Intact attentional control of working memory encoding in schizophrenia

Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, USA.
Journal of Abnormal Psychology (Impact Factor: 5.15). 12/2006; 115(4):658-73. DOI: 10.1037/0021-843X.115.4.658
Source: PubMed


This study reports evidence that individuals with schizophrenia (SC) demonstrate intact attentional selection for visual working memory (WM) storage. A group of 62 participants with SC and 55 control participants without SC were studied in a series of 5 experiments that examined the ability to use top-down and bottom-up cues to guide WM encoding, as well as the ability to spontaneously select a subset of representations for storage. Participants with SC exhibited a consistent and robust ability to use selective attention in the control of WM in all 5 experiments, demonstrating a remarkable island of preserved functioning given the broad spectrum of impairments of attention and WM that have been widely reported in those with SC. These findings indicate that attention is not globally impaired in SC and make it possible to delineate more precisely the nature of the specific impairment of attention in this disorder.

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Available from: Rebecca L Fuller
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    • "We found no impairment of attention in D2R-OE mice. Although impairments in attention (broadly defined) have been widely reported in schizophrenia (Heinrichs & Zakzanis, 1998; Demeter, Guthrie, Taylor, Sarter, & Lustig, 2013; Nuechterlein et al., 2004), detailed analysis of the specific nature of attentional deficits in schizophrenia shows unimpaired selection of highly salient inputs for attentional processing (Gold et al., 2006; Luck & Gold, 2008), as in our sustained-attention task. Instead, patients with schizophrenia are impaired in the executive control of attention , such as guided searching and resistance to distraction (Luck & Gold, 2008). "
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    ABSTRACT: Interactions between motivation and cognition are implicated in producing functional impairments and poor quality of life in psychiatric patients. This interaction, however, is not well understood at either the behavioral or neural level. We developed a procedure for mice in which a cognitive measure, sustained attention, is modulated by a motivationally relevant signal that predicts reward probability on a trial-by-trial basis. Using this paradigm, we tested the interaction between motivation and cognition in mice that model the increased striatal D2 receptor activity observed in schizophrenia patients (D2R-OE mice). In control mice, attention was modulated by signaled-reward probability. In D2R-OE mice, however, attention was not modulated by reward-related cues. This impairment was not due to any global deficits in attention or maintenance of the trial-specific information in working memory. Turning off the transgene in D2R-OE mice rescued the motivational modulation of attention. These results indicate that deficits in motivation impair the ability to use reward-related cues to recruit attention and that improving motivation improves functional cognitive performance. These results further suggest that addressing motivational impairments in patients is critical to achieving substantive cognitive and functional gains. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
    Full-text · Article · Apr 2015 · Behavioral Neuroscience
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    • "Similarly, Smith et al. (2011) found that PSZ were able to use color cues to guide target words into WM storage and exclude non-target words—again, despite overall reductions in capacity. These recent studies are consistent with earlier work from Gold et al. (2006) demonstrating that PSZ are able to select task-relevant items for WM storage while inhibiting the encoding of task-irrelevant items. One exception may be a failure to filter out extremely salient distractors (especially those that strongly activate the magnocellular pathway) during the encoding of low-salience target items (Hahn et al., 2010; Leonard et al., 2014). "
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    ABSTRACT: Although working memory impairment has been well-documented among people with schizophrenia (PSZ), the underlying mechanism of this impairment remains unknown. The present study was conducted in a large sample of PSZ and healthy control subjects (HCS) to test the hypothesis that one putative mechanism – vulnerability to distraction from task-irrelevant stimuli – (1) can account for working memory impairment among PSZ, and (2) is associated with other neurocognitive and clinical variables that are highly predictive of functional outcome in schizophrenia. Participants (127 PSZ and 124 HCS) completed a visual change detection task in which a distractor stimulus (mask) was presented on half of the trials during the delay period between sample and test array. PSZ lost proportionately more information from working memory than did HCS, but this effect was small (Cohen’s d = 0.36–0.38), and large differences between groups in working memory capacity remained when differences in distractibility were factored out. Furthermore, vulnerability to distraction was not strongly associated with any clinical or cognitive variables of interest. These results suggest that, although PSZ may be somewhat more susceptible to distraction than HCS, this impairment is unlikely to be a significant factor accounting for the robust capacity deficits observed in this population.
    Full-text · Article · Sep 2014 · Schizophrenia Research: Cognition
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    • "For example, high-capacity individuals get higher scores in fluid intelligence measures and in complex cognitive tasks such as verbal learning and problem solving compared to low-capacity individuals (Cowan et al., 2005; Fukuda et al., 2010; Johnson et al., 2013). Furthermore, impairments in visual WM functioning were associated with old age (Cashdollar et al., 2013) and with psychiatric disorders such as schizophrenia (Gold et al., 2003, 2006) and Alzheimer (Parra et al., 2010a,b, 2011). In addition, a recent electrophysiological study in monkeys (Buschman et al., 2011) suggested that each hemifield acts as an independent memory capacity limited resource (as limited-items models suggest; e.g., Zhang and Luck, 2008), and that within each hemifield memory resources are shared between the items represented in that hemifield (as flexible-resource models suggest; e.g., Bays and Husain, 2008). "
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    ABSTRACT: In three experiments we manipulated the resolution of novel complex objects in visual working memory (WM) by changing task demands. Previous studies that investigated the trade-off between quantity and resolution in visual WM yielded mixed results for simple familiar stimuli. We used the contralateral delay activity as an electrophysiological marker to directly track the deployment of visual WM resources while participants preformed a change-detection task. Across three experiments we presented the same novel complex items but changed the task demands. In Experiment 1 we induced a medium resolution task by using change trials in which a random polygon changed to a different type of polygon and replicated previous findings showing that novel complex objects are represented with higher resolution relative to simple familiar objects. In Experiment 2 we induced a low resolution task that required distinguishing between polygons and other types of stimulus categories, but we failed in finding a corresponding decrease in the resolution of the represented item. Finally, in Experiment 3 we induced a high resolution task that required discriminating between highly similar polygons with somewhat different contours. This time, we observed an increase in the item's resolution. Our findings indicate that the resolution for novel complex objects can be increased but not decreased according to task demands, suggesting that minimal resolution is required in order to maintain these items in visual WM. These findings support studies claiming that capacity and resolution in visual WM reflect different mechanisms.
    Full-text · Article · Mar 2014 · Frontiers in Psychology
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