Search results for "Working memory"
showing 10 items of 315 documents
A meta-analysis of cognitive performance in melancholic versus non-melancholic unipolar depression
2016
Abstract Background Recently there is increasing recognition of cognitive dysfunction as a core feature of Major Depressive Disorder (MDD). The goal of the current meta-analysis was to review and examine in detail the specific features of cognitive dysfunction in Melancholic (MEL) versus Non-Melancholic (NMEL) MDD. Methods An electronic literature search was performed to find studies comparing cognitive performance in MEL versus NMEL. A meta-analysis of broad cognitive domains ( processing speed , reasoning/problem solving , verbal learning , visual learning , attention/working memory ) was conducted on all included studies (n=9). Sensitivity and meta-regression analyses were also conducted…
Object switching within working memory is reflected in the human event-related brain potential
2008
In two experiments applying a memory updating task subjects are asked to perform several arithmetic operations on stored numbers. From a trial-to-trial perspective these operations could be either performed on a previously processed item or on a new item which requires an object switch in working memory. Object switching results in prolonged operation times; these operation time costs reflect the switch of the focus of attention to the relevant information. Event-related brain potentials obtained in object switch trials show an increased P3a around 300 ms and a late, central negative component between 400 ms and 500 ms. The data suggest that the P3a may reflect the unhitching of the focus o…
Exploring the switching of the focus of attention within working memory: A combined event-related potential and behavioral study.
2018
Abstract Working memory enables humans to maintain selected information for cognitive processes and ensures instant access to the memorized contents. Theories suggest that switching the focus of attention between items within working memory realizes the access. This is reflected in object-switching costs in response times when the item for the task processing is to be changed. Another correlate of attentional allocation in working memory is the P3a-component of the human event-related potential. The aim of this study was to demonstrate that switching of attention within working memory is a separable processing step. Participants completed a cued memory-updating task in which they were instr…
Does the Coordination of Verbal and Motor Information Explain the Development of Counting in Children?
2001
Counting is often considered to be the coordination of two actions: saying the number-words and pointing to each object. We report three experiments to test the hypothesis that this coordination requires the use of the central executive (A. D. Baddeley, 1990), and that the cost of coordination decreases with age. Participants were 5- and 9-year-old children and adults. At all ages tested, the manipulation of the difficulty of each component affected counting performance but did not make coordination more difficult. These results suggest that, at least from the age 5, counting is a procedure in which the control of coordination is not attention demanding.
Covariations among fMRI, skin conductance, and behavioral data during processing of concealed information.
2007
Imaging techniques have been used to elucidate the neural correlates that underlie deception. The scientifically best understood paradigm for the detection of deception, however, the guilty knowledge test (GKT), was rarely used in imaging studies. By transferring a GKT‐paradigm to a functional magnetic resonance imaging (fMRI) study, while additionally quantifying reaction times and skin conductance responses (SCRs), this study aimed at identifying the neural correlates of the behavioral and electrodermal response pattern typically found in GKT examinations. Prior to MR scanning, subjects viewed two specific items (probes) and were instructed to hide their knowledge of these. Two other spec…
The role of working memory in the association between number magnitude and space.
2007
In two experiments, participants performed a magnitude comparison task in single and dual-task conditions. In the dual conditions, the comparison task was accomplished while phonological or visuospatial information had to be maintained for a later recall test. The results showed that the requirement of maintaining visuospatial information produced the lack of spatial-numerical association of response codes (SNARC) effect. The SNARC effect was not found even when the performance in the comparison task did not decline, as indicated by a similar distance effect in all conditions. These results show a special role for the visuospatial component of working memory in the processing of spatial rep…
Separable neural bases for subprocesses of recognition in working memory.
2011
Working memory supports the recognition of objects in the environment. Memory models have postulated that recognition relies on 2 processes: assessing the degree of similarity between an external stimulus and memory representations and testing the resulting summed-similarity value against a critical level for recognition. Here, we varied the similarity between samples held in working memory and a probe to investigate these 2 processes with magnetoencephalography. Two separable components matched our expectations: First, from 280 ms after probe onset, clearly nonmatching probes differed from both similar nonmatches and matches over left frontal cortex. At 350--400 ms, these signals evolved i…
Task-Modulated Corticocortical Synchrony in the Cognitive-Motor Network Supporting Handwriting
2019
Abstract Both motor and cognitive aspects of behavior depend on dynamic, accurately timed neural processes in large-scale brain networks. Here, we studied synchronous interplay between cortical regions during production of cognitive-motor sequences in humans. Specifically, variants of handwriting that differed in motor variability, linguistic content, and memorization of movement cues were contrasted to unveil functional sensitivity of corticocortical connections. Data-driven magnetoencephalography mapping (n = 10) uncovered modulation of mostly left-hemispheric corticocortical interactions, as quantified by relative changes in phase synchronization. At low frequencies (~2–13 Hz), enhanced …
Evidence against preserved syntactic comprehension in healthy aging.
2018
We investigated age-related differences in syntactic comprehension in young and older adults. Most previous research found no evidence of age-related decline in syntactic processing. We investigated elementary syntactic comprehension of minimal sentences (e.g., I cook), minimizing the influence of working memory. We also investigated the contribution of semantic processing by comparing sentences containing real verbs (e.g., I cook) versus pseudoverbs (e.g., I spuff). We measured the speed and accuracy of detecting syntactic agreement errors (e.g., I cooks, I spuffs). We found that older adults were slower and less accurate than younger adults in detecting syntactic agreement errors for both…
Spatial Inferences in Narrative Comprehension: the Role of Verbal and Spatial Working Memory
2016
During the comprehension of narrative texts, readers keep a mental representation of the location of protagonists and objects; a breach in spatial coherence is detected by longer online reading times (consistency effect). We addressed whether these spatial inferences involve verbal or spatial working memory in two experiments, combining the consistency paradigm with selective verbal and spatial working memory concurrent tasks. The first experiment found longer reading times with a concurrent spatial task under imagery instructions (t33 = 2.87, p =.021). The second experiment, under comprehension reading instructions, found effects of verbal interference on reading times and accuracy. With a…