scholarly journals Neural correlates of enhanced working-memory performance in dissociative disorder: a functional MRI study

2006 ◽  
Vol 37 (2) ◽  
pp. 235-245 ◽  
Author(s):  
BERNET M. ELZINGA ◽  
ANGELIQUE M. ARDON ◽  
MAAIKE K. HEIJNIS ◽  
MICHIEL B. De RUITER ◽  
RICHARD VAN DYCK ◽  
...  
Keyword(s):  
Working Memory ◽  
Parietal Cortex ◽  
Memory Performance ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Brain Regions ◽  
Dissociative Disorder ◽  
Imaging Data ◽  
Post Traumatic Stress ◽  
Task Load

Background. Memory functioning has been highlighted as a central issue in pathological dissociation. In non-pathological dissociation, evidence for enhanced working memory has been found, together with greater task-load related activity. So far, no imaging studies have investigated working memory in dissociative patients.Method. To assess working memory in dissociative patients functional magnetic resonance imaging was used during performance of a parametric, verbal working-memory task in patients with a dissociative disorder (n=16) and healthy controls (n=16).Results. Imaging data showed that both groups activated brain regions typically involved in working memory, i.e. anterior, dorsolateral and ventrolateral prefrontal cortex (PFC), and parietal cortex. Dissociative patients showed more activation in these areas, particularly in the left anterior PFC, dorsolateral PFC and parietal cortex. In line with these findings, patients made fewer errors with increasing task load compared to controls, despite the fact that they felt more anxious and less concentrated during task performance.Conclusions. These results extend findings in non-pathological high dissociative individuals, suggesting that trait dissociation is associated with enhanced working-memory capacities. This may distinguish dissociative patients from patients with post-traumatic stress disorder, who are generally characterized by impaired working memory.

Default Mode and Temporal Lobe Networks Activity During a Working Memory Performance in Schizophrenia

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
K. Verébová ◽  
J. Horáček
Keyword(s):  
Working Memory ◽  
Temporal Lobe ◽  
Memory Performance ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Bold Signal ◽  
Default Mode ◽  
Temporal Correlations

Background:Temporal correlations in the blood oxygen level-dependent (BOLD) signal oscillations of widely separated brain regions are presumed to reflect intrinsic functional connectivity and have been demonstrated across several distinct networks serving different functions. Impaired connectivity or disturbed integration of neural activity, as seen in brain networks in schizophrenia, might influence the symptoms of the disorder and biologically implicates in temporal and spatial alterations in BOLD signal fluctuations.The objective of this study is to examine the activity of a temporal lobe and default modes during working memory task in schizophrenic patients. These two networks were selected because both have been previously studied.Methods:Patients with schizophrenia and healthy comparison subjects undergo functional magnetic resonance imaging (fMRI) scanning while performing a verbal working memory “n-back” task. All subjects receive identical training in task performance prior to scanning. Independent component analysis will be used to identify the default mode and temporal lobe component. Spatial and temporal aspects of the networks will be examined in patients versus healthy control subjects.Results:Data collection and statistical evaluation will proceed until October 2008.Conclusions:Identifying specific activation patterns for the temporal lobe and default mode components may contribute to the identification of a trait-related marker for schizophrenia and improve diagnostic sensitivity and specificity.

scholarly journals Neurophysiological correlates of increased verbal working memory in high-dissociative participants: a functional MRI study

2005 ◽  
Vol 35 (2) ◽  
pp. 175-185 ◽  
Author(s):  
DICK J. VELTMAN ◽  
MICHIEL B. De RUITER ◽  
SERGE A. R. B. ROMBOUTS ◽  
RICHARD H. C. LAZERON ◽  
FREDERIK BARKHOF ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Parietal Cortex ◽  
Working Memory Capacity ◽  
Verbal Working Memory ◽  
Imaging Data ◽  
Post Traumatic Stress ◽  
Processing Style ◽  
Post Traumatic ◽  
Mri Study

Background. Dissociation, defined as a disruption in usually integrated mental functions, is found not only in DSM-IV dissociative disorders, but also in post-traumatic stress disorder and eating disorders. Dissociative phenomena are also common in the general population, and may reflect a constitutionally determined cognitive style rather than a pathological trait acquired through experiencing adverse life events. In pathological dissociation, evidence has been presented for episodic memory dysfunction. In contrast, in high-dissociative subjects increased performance has been found for episodic memory and dual task performance. These findings have been linked to changes in working memory capacity.Method. In the present study, the authors sought to extend these findings by using functional magnetic resonance imaging during performance of two parametric working memory tasks. We tested 21 healthy low- and high-dissociative participants.Results. High-dissociative participants performed slightly better during both tasks. Imaging data showed that both groups activated similar networks for both tasks, i.e. (bilateral) dorsolateral (DL) and ventrolateral prefrontal cortex (PFC), parietal cortex, and supplementary motor area. Group×task interactions were found in the high-dissociative group in L DLPFC and L parietal cortex; in the low-dissociative group in R fusiform gyrus. The differences in the high-dissociative group were independent from performance differences, implying that high-dissociative subjects generally recruit this network to a greater extent.Conclusions. These results confirm earlier findings using a verbal WM task in high-dissociative participants, and are compatible with the conceptualization of non-pathological dissociation as an information-processing style, characterized by distinct attentional and mnemonic abilities.

scholarly journals The olfactory bulb modulates entorhinal cortex oscillations during spatial working memory

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Morteza Salimi ◽  
Farhad Tabasi ◽  
Milad Nazari ◽  
Sepideh Ghazvineh ◽  
Alireza Salimi ◽  
...  
Keyword(s):  
Working Memory ◽  
Olfactory Bulb ◽  
Entorhinal Cortex ◽  
Spatial Working Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Low Frequency ◽  
Rhythmic Activity ◽  
Brain Regions ◽  
Simultaneous Recording

AbstractCognitive functions such as working memory require integrated activity among different brain regions. Notably, entorhinal cortex (EC) activity is associated with the successful working memory task. Olfactory bulb (OB) oscillations are known as rhythms that modulate rhythmic activity in widespread brain regions during cognitive tasks. Since the OB is structurally connected to the EC, we hypothesized that OB could modulate EC activity during working memory performance. Herein, we explored OB–EC functional connectivity during spatial working memory performance by simultaneous recording local field potentials when rats performed a Y-maze task. Our results showed that the coherence of delta, theta, and gamma-band oscillations between OB and EC was increased during correct trials compared to wrong trials. Cross-frequency coupling analyses revealed that the modulatory effect of OBs low-frequency phase on EC gamma power and phase was enhanced when animals correctly performed working memory task. The influx of information from OB to EC was also increased at delta and gamma bands within correct trials. These findings indicated that the modulatory influence of OB rhythms on EC oscillations might be necessary for successful working memory performance.

scholarly journals Lower Working Memory Performance in Overweight and Obese Adolescents Is Mediated by White Matter Microstructure

2015 ◽  
Vol 22 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Gabriela Alarcón ◽  
Siddharth Ray ◽  
Bonnie J. Nagel
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Spatial Working Memory ◽  
Memory Performance ◽  
Gray Matter Volume ◽  
Verbal Working Memory ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Bold Signal ◽  
The Relationship

AbstractObjectives: Elevated body mass index (BMI) is associated with deficits in working memory, reduced gray matter volume in frontal and parietal lobes, as well as changes in white matter (WM) microstructure. The current study examined whether BMI was related to working memory performance and blood oxygen level dependent (BOLD) activity, as well as WM microstructure during adolescence. Methods: Linear regressions with BMI and (1) verbal working memory BOLD signal, (2) spatial working memory BOLD signal, and (3) fractional anisotropy (FA), a measure of WM microstructure, were conducted in a sample of 152 healthy adolescents ranging in BMI. Results: BMI was inversely related to IQ and verbal and spatial working memory accuracy; however, there was no significant relationship between BMI and BOLD response for either verbal or spatial working memory. Furthermore, BMI was negatively correlated with FA in the left superior longitudinal fasciculus (SLF) and left inferior longitudinal fasciculus (ILF). ILF FA and IQ significantly mediated the relationship between BMI and verbal working memory performance, whereas SLF FA, but not IQ, significantly mediated the relationship between BMI and accuracy of both verbal and spatial working memory. Conclusions: These findings indicate that higher BMI is associated with decreased FA in WM fibers connecting brain regions that support working memory, and that WM microstructural deficits may underlie inferior working memory performance in youth with higher BMI. Of interest, BMI did not show the same relationship with working memory BOLD activity, which may indicate that changes in brain structure precede changes in function. (JINS, 2015, 21, 281–292)

Verbal and spatial working memory performance among HIV-infected adults

2002 ◽  
Vol 8 (4) ◽  
pp. 532-538 ◽  
Author(s):  
CHARLES H. HINKIN ◽  
DAVID J. HARDY ◽  
KAREN I. MASON ◽  
STEVEN A. CASTELLON ◽  
MONA N. LAM ◽  
...  
Keyword(s):  
Working Memory ◽  
Mixed Model ◽  
Spatial Working Memory ◽  
Memory Performance ◽  
Memory Task ◽  
Executive Dysfunction ◽  
Spatial Location ◽  
Verbal Working Memory ◽  
Memory Condition ◽  
Percent Accuracy

Subtypes of working memory performance were examined in a cohort of 50 HIV-infected adults and 23 uninfected controls using an n-back paradigm (2-back) in which alphabetic stimuli were quasi-randomly presented to a quadrant of a computer monitor. In the verbal working memory condition, participants determined whether each successive letter matched the letter that appeared two previously in the series, regardless of spatial location. In the spatial working memory condition, participants determined whether each letter matched the spatial location of the letter that had appeared two previously, regardless of letter identity. The dependent variable was percent accuracy in each condition. Results of mixed model ANOVA revealed that the HIV-infected participants performed significantly worse than controls on both the verbal and spatial working memory tasks. A significant main effect for working memory condition was also present with both participant groups performing better on the spatial working memory task. These results, the first study of HIV-infected adults to directly compare verbal versus spatial working memory performance using the identical test stimuli across task conditions, suggests that HIV infection is associated with a decrement in working memory efficiency that is equally apparent for both verbal and spatial processing. These findings implicate central executive dysfunction as a likely substrate and provide the basis for hypothesizing that decline in working memory may contribute to other HIV-associated neuropsychological deficits. (JINS, 2002, 8, 532–538.)

scholarly journals Validating Age-Related Functional Imaging Changes in Verbal Working Memory with Acute Stroke

2011 ◽  
Vol 24 (3) ◽  
pp. 187-199 ◽  
Author(s):  
Timothy B. Meier ◽  
Lin Naing ◽  
Lisa E. Thomas ◽  
Veena A. Nair ◽  
Argye E. Hillis ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Acute Stroke ◽  
Functional Imaging ◽  
Memory Task ◽  
Recognition Task ◽  
Verbal Working Memory ◽  
Brain Regions ◽  
Stroke Patients ◽  
Younger Adults

Functional imaging studies consistently find that older adults recruit bilateral brain regions in cognitive tasks that are strongly lateralized in younger adults, a characterization known as the Hemispheric Asymmetry Reduction in Older Adults model. While functional imaging displays what brain areas are active during tasks, it cannot demonstrate what brain regions are necessary for task performance. We used behavioral data from acute stroke patients to test the hypothesis that older adults need both hemispheres for a verbal working memory task that is predominantly left-lateralized in younger adults. Right-handed younger (age ≥ 50,n= 7) and older adults (age > 50,n= 21) with acute unilateral stroke, as well as younger (n= 6) and older (n= 13) transient ischemic attack (TIA) patients, performed a self-paced verbal item-recognition task. Older patients with stroke to either hemisphere had a higher frequency of deficits in the verbal working memory task compared to older TIA patients. Additionally, the deficits in older stroke patients were mainly in retrieval time while the deficits in younger stroke patients were mainly in accuracy. These data suggest that bihemispheric activity is necessary for older adults to successfully perform a verbal working memory task.

Dissociation of Storage and Rehearsal in Verbal Working Memory: Evidence From Positron Emission Tomography

1996 ◽  
Vol 7 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Edward Awh ◽  
John Jonides ◽  
Edward E. Smith ◽  
Eric H. Schumacher ◽  
Robert A. Koeppe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Working Memory ◽  
Memory Task ◽  
Recognition Task ◽  
Verbal Working Memory ◽  
Brain Regions ◽  
Emission Tomography ◽  
Positron Emission ◽  
Rehearsal Strategy ◽  
Phonological Store

Current cognitive models of verbal working memory include two components a phonological store and a rehearsal mechanism that refreshes the contents of this store We present research using positron emission tomography (PET) to provide further evidence for this functional division In Experiment 1, subjects performed a variant of Sternberg's (1966) item recognition task Experiment 2 used a continuous memory task with control conditions designed to separate the brain regions underlying storage and rehearsal The results show that independent brain regions mediate storage and rehearsal In Experiment 3, a dual-task procedure supported the assumption that these memory tasks elicited a rehearsal strategy

Mindfulness Training as Cognitive Training in High-Demand Cohorts: An Initial Study in Elite Military Servicemembers

2018 ◽  
Author(s):  
Anthony Paul Zanesco ◽  
Ekaterina Denkova ◽  
Scott L. Rogers ◽  
William K. MacNulty ◽  
Amishi P. Jha
Keyword(s):  
Working Memory ◽  
Cognitive Training ◽  
Short Form ◽  
Memory Performance ◽  
Memory Task ◽  
Selection Criterion ◽  
Initial Study ◽  
Mindfulness Training ◽  
Training Tool ◽  
Cognitive Failures

Cognitive ability is a key selection criterion for entry into many elite professions. Herein, we investigate whether mindfulness training (MT) can enhance cognitive performance in elite military forces. The cognitive effects of a short-form 8-hour MT program contextualized for military cohorts, referred to as Mindfulness-Based Attention Training (MBAT), were assessed. Servicemembers received either a 2-week (n = 40) or 4-week (n = 36) version of MBAT, or no training (NTC, n = 44). Sustained attention and working memory task performance along with self-reported cognitive failures were assessed at study onset (T1) and 8-weeks later (T2). In contrast to both the NTC and 2-week MT groups, the 4-week MT group significantly improved over time on attention and working memory outcome measures. Among the 4-week more so than the 2-week MBAT participants, working memory performance improvements were correlated with their amount of out-of-class MT practice. In addition to these group-wise effects, all participants receiving MBAT decreased in their self-reported cognitive failures from T1 to T2. Importantly, none of these improvements were related to self-reported task motivation. Together, these results suggest that short-form MT, when delivered over a 4-week delivery schedule, may be an effective cognitive training tool in elite military cohorts.

scholarly journals Resting‐State EEG Microstates Parallel Age‐Related Differences in Allocentric Spatial Working Memory Performance

2021 ◽  
Author(s):  
Adeline Jabès ◽  
Giuliana Klencklen ◽  
Paolo Ruggeri ◽  
Christoph M. Michel ◽  
Pamela Banta Lavenex ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Resting State ◽  
Cognitive Aging ◽  
Temporal Dynamics ◽  
Spatial Working Memory ◽  
Brain Activity ◽  
Memory Performance ◽  
Brain Regions ◽  
Age Related

AbstractAlterations of resting-state EEG microstates have been associated with various neurological disorders and behavioral states. Interestingly, age-related differences in EEG microstate organization have also been reported, and it has been suggested that resting-state EEG activity may predict cognitive capacities in healthy individuals across the lifespan. In this exploratory study, we performed a microstate analysis of resting-state brain activity and tested allocentric spatial working memory performance in healthy adult individuals: twenty 25–30-year-olds and twenty-five 64–75-year-olds. We found a lower spatial working memory performance in older adults, as well as age-related differences in the five EEG microstate maps A, B, C, C′ and D, but especially in microstate maps C and C′. These two maps have been linked to neuronal activity in the frontal and parietal brain regions which are associated with working memory and attention, cognitive functions that have been shown to be sensitive to aging. Older adults exhibited lower global explained variance and occurrence of maps C and C′. Moreover, although there was a higher probability to transition from any map towards maps C, C′ and D in young and older adults, this probability was lower in older adults. Finally, although age-related differences in resting-state EEG microstates paralleled differences in allocentric spatial working memory performance, we found no evidence that any individual or combination of resting-state EEG microstate parameter(s) could reliably predict individual spatial working memory performance. Whether the temporal dynamics of EEG microstates may be used to assess healthy cognitive aging from resting-state brain activity requires further investigation.

scholarly journals Working Memory Performance under a Negative Affect Is More Susceptible to Higher Cognitive Workloads with Different Neural Haemodynamic Correlates

2021 ◽  
Vol 11 (7) ◽  
pp. 935
Author(s):  
Ying Xing Feng ◽  
Masashi Kiguchi ◽  
Wei Chun Ung ◽  
Sarat Chandra Dass ◽  
Ahmad Fadzil Mohd Hani ◽  
...  
Keyword(s):  
Working Memory ◽  
Task Performance ◽  
Memory Performance ◽  
Affective State ◽  
Memory Task ◽  
Interactive Effects ◽  
Functional Near Infrared Spectroscopy ◽  
Affective Factors ◽  
Related Stress ◽  
Haemodynamic Activity

The effect of stress on task performance is complex, too much or too little stress negatively affects performance and there exists an optimal level of stress to drive optimal performance. Task difficulty and external affective factors are distinct stressors that impact cognitive performance. Neuroimaging studies showed that mood affects working memory performance and the correlates are changes in haemodynamic activity in the prefrontal cortex (PFC). We investigate the interactive effects of affective states and working memory load (WML) on working memory task performance and haemodynamic activity using functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants. We seek to understand if haemodynamic responses could tell apart workload-related stress from situational stress arising from external affective distraction. We found that the haemodynamic changes towards affective stressor- and workload-related stress were more dominant in the medial and lateral PFC, respectively. Our study reveals distinct affective state-dependent modulations of haemodynamic activity with increasing WML in n-back tasks, which correlate with decreasing performance. The influence of a negative effect on performance is greater at higher WML, and haemodynamic activity showed evident changes in temporal, and both spatial and strength of activation differently with WML.

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