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.

scholarly journals Testing Conclusions From Functional Imaging of Working Memory with Data From Acute Stroke

2007 ◽  
Vol 18 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Lisa E. Philipose ◽  
Hannah Alphs ◽  
Vivek Prabhakaran ◽  
Argye E. Hillis
Keyword(s):  
Working Memory ◽  
Acute Stroke ◽  
Functional Imaging ◽  
Right Hemisphere ◽  
Spatial Working Memory ◽  
Verbal Working Memory ◽  
Stroke Patients ◽  
Imaging Results ◽  
Cortical Stroke ◽  
The Right

Functional imaging studies indicate that the left hemisphere mediates verbal working memory, while the right hemisphere mediates both verbal and spatial working memory. We evaluated acute stroke patients with working memory tests and imaging to identify whether unilateral dysfunction causes deficits in spatial and/or verbal working memory deficits. While left cortical stroke patients had verbal working memory impairments (p< 0.003), right cortical stroke patients had both verbal (p< 0.007) and spatial working memory (p< 0.03) impairments, confirming functional imaging results. Patients with transient ischemic stroke and patients with non-cortical stroke did not have significant deficits in working memory in either modality.

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

scholarly journals Does working memory protect against auditory distraction in older adults?

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yatin Mahajan ◽  
Jeesun Kim ◽  
Chris Davis
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Correct Response ◽  
Response Times ◽  
Memory Task ◽  
Past Research ◽  
Error Rates ◽  
Visual Task ◽  
Oddball Paradigm ◽  
Younger Adults

Abstract Background Past research indicates that when younger adults are engaged in a visual working memory task, they are less distracted by novel auditory stimuli than when engaged in a visual task that does not require working memory. The current study aimed to determine whether working memory affords the same protection to older adults. Method We examined behavioral and EEG responses in 16 younger and 16 older adults to distractor sounds when the listeners performed two visual tasks; one that required working memory (W1) and the other that did not (W0). Auditory distractors were presented in an oddball paradigm, participants were exposed to either standard tones (600 Hz: 80%) or various novel environmental sounds (20%). Results It was found that: 1) when presented with novel vs standard sounds, older adults had faster correct response times in the W1 visual task than in the W0 task, indicating that they were less distracted by the novel sound; there was no difference in error rates. Younger adults did not show a task effect for correct response times but made slightly more errors when a novel sound was presented in the W1 task compared to the W0 task. 2) In older adults (but not the younger adults), the amplitude of N1 was smaller in the W1 condition compared to the W0 condition. 3) The working memory manipulation had no effect on MMN amplitude in older adults. 4) For the W1 compared to W0 task, the amplitude of P3a was attenuated for the older adults but not for the younger adults. Conclusions These results suggest that during the working memory manipulation older adults were able to engage working memory to reduce the processing of task-irrelevant sounds.

scholarly journals What affects the magnitude of age-related dual-task costs in working memory? The role of stimulus domain and access to semantic representations

2020 ◽  
pp. 174702182097074
Author(s):  
Agnieszka J Jaroslawska ◽  
Stephen Rhodes ◽  
Clément Belletier ◽  
Jason M Doherty ◽  
Nelson Cowan ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Dual Task ◽  
Memory Task ◽  
Semantic Representations ◽  
Younger Adults ◽  
Task Effects ◽  
Concurrent Processing ◽  
Age Related

Although there is evidence that the effect of including a concurrent processing demand on the storage of information in working memory is disproportionately larger for older than younger adults, not all studies show this age-related impairment, and the critical factors responsible for any such impairment remain elusive. Here we assess whether domain overlap between storage and processing activities, and access to semantic representations, are important determinants of performance in a sample of younger and older adults ( N = 119). We developed four versions of a processing task by manipulating the type of stimuli involved (either verbal or non-verbal) and the decision that participants had to make about the stimuli presented on the screen. Participants either had to perform a spatial judgement, in deciding whether the verbal or non-verbal item was presented above or below the centre of the screen, or a semantic judgement, in deciding whether the stimulus refers to something living or not living. The memory task was serial-ordered recall of visually presented letters. The study revealed a large increase in age-related memory differences when concurrent processing was required. These differences were smaller when storage and processing activities both used verbal materials. Dual-task effects on processing were also disproportionate for older adults. Age differences in processing performance appeared larger for tasks requiring spatial decisions rather than semantic decisions. We discuss these findings in relation to three competing frameworks of working memory and the extant literature on cognitive ageing.

scholarly journals Age Differences in Behavior and PET Activation Reveal Differences in Interference Resolution in Verbal Working Memory

2000 ◽  
Vol 12 (1) ◽  
pp. 188-196 ◽  
Author(s):  
John Jonides ◽  
Christina Marshuetz ◽  
Edward E. Smith ◽  
Patricia A. Reuter-Lorenz ◽  
Robert A. Koeppe ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Prefrontal Cortex ◽  
Age Differences ◽  
Positive Response ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Item Recognition ◽  
Test Items ◽  
A Current

Older adults were tested on a verbal working memory task that used the item-recognition paradigm. On some trials of this task, response-conflict was created by presenting test-items that were familiar but were not members of a current set of items stored in memory. These items required a negative response, but their familiarity biased subjects toward a positive response. Younger subjects show an interference effect on such trials, and this interference is accompanied by activation of a region of left lateral prefrontal cortex. However, there has been no evidence that the activation in this region is causally related to the interference that the subjects exhibit. In the present study, we demonstrate that older adults show more behavioral interference than younger subjects on this task, and they also show no reliable activation at the same lateral prefrontal site. This leads to the conclusion that this prefrontal site is functionally involved in mediating resolution among conflicting responses or among conflicting representations in working memory.

scholarly journals Working Memory for Complex Scenes: Age Differences in Frontal and Hippocampal Activations

2003 ◽  
Vol 15 (8) ◽  
pp. 1122-1134 ◽  
Author(s):  
Denise C. Park ◽  
Robert C. Welsh ◽  
Christy Marshuetz ◽  
Angela H. Gutchess ◽  
Joseph Mikels ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Age Differences ◽  
Memory Task ◽  
Younger Adults ◽  
Behavioral Equivalence ◽  
Probe Task ◽  
Complex Scenes ◽  
Left And Right ◽  
Older Subjects

Age differences in frontal and hippocampal activations in working memory were investigated during a maintenance and subsequent probe interval in an event-related fMRI design. Younger and older adults either viewed or maintained photographs of real-world scenes (extended visual or maintenance conditions) over a 4-sec interval before responding to a probe fragment from the studied picture. Behavioral accuracy was largely equivalent across age and conditions on the probe task, but underlying neural activations differed. Younger but not older adults showed increased left anterior hippocampal activations in the extended visual compared with the maintenance condition. Onthesubsequent probeinterval, however, older adultsshowed more left and right inferior frontal activations than younger adults. The increased frontal activations at probe in older adults may have been compensatory for the decreased hippocampal activations during maintenance, but alternatively could have reflected the increased difficulty of the probe task for the older subjects. Thus, we demonstrate qualitatively different engagement of both frontal and hippocampal structures in older adults in a working memory task, despite behavioral equivalence.

scholarly journals Functional MRI Study of Gender Effects in Brain Activations During Verbal Working Memory Task

2018 ◽  
pp. 825-829 ◽  
Author(s):  
Z. TÜDÖS ◽  
P. HOK ◽  
P. HLUŠTÍK ◽  
A. GRAMBAL
Keyword(s):  
Working Memory ◽  
Functional Mri ◽  
Memory Task ◽  
Recognition Task ◽  
Brain Activation ◽  
Verbal Working Memory ◽  
Gender Effects ◽  
Behavioral Data ◽  
Single Subject ◽  
Significant Difference

Neuroimaging methods have been used to study differences of brain function between males and females. Differences in working memory have been also investigated, but results of such studies are mixed with respect to behavioral data, reaction times and activated brain areas. We tried to analyze functional MRI data acquired during the working memory task and search for differences of brain activation between genders. 20 healthy right-handed volunteers (10 males and 10 females) participated in the study. All of them were university students or fresh graduates. Subjects underwent block designed verbal working memory task (Item Recognition Task) inside the MRI scanner. Standard single-subject pre-processing and group fMRI analyses were performed using the FEAT software from FSL library. In the behavioral data, there was no statistically significant difference in the number of correct responses during the task. The task activated similar bilateral regions of frontal, parietal, temporal and occipital lobes, basal ganglia, the brainstem and in the cerebellum, which corresponds to the previous verbal working memory neuroimaging research. In direct comparison, there was no statistically significant difference in brain activation between small samples of male and female young healthy volunteers.

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 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.

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