scholarly journals Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping

2021 ◽  
Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Memory Task ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
Criterion Setting ◽  
The Right

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

scholarly journals Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping.

2021 ◽  
Author(s):  
Selma Lugtmeijer ◽  
Linda Geerligs ◽  
Frank Erik De Leeuw ◽  
Edward H. F. De Haan ◽  
Roy P. C. Kessels
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Memory Task ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
Criterion Setting ◽  
The Right

Abstract Working memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, eighty-one adults with sub-acute ischemic stroke and twenty-nine elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

scholarly journals Contribution of right hemisphere to visual imagery: A visual working memory impairment?

2008 ◽  
Vol 14 (5) ◽  
pp. 902-911 ◽  
Author(s):  
MARINA GASPARINI ◽  
ANNE MARIE HUFTY ◽  
GIOVANNI MASCIARELLI ◽  
DONATELLA OTTAVIANI ◽  
UGO ANGELONI ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Visual Imagery ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Anterior Choroidal ◽  
The Right ◽  
Mind's Eye ◽  
Choroidal Artery

Visual Imagery is the ability to generate mental images in the absence of perception, that is, “seeing with the mind's eye.” We describe a patient, IM, who suffered from an acute ischemic stroke in the right anterior choroidal artery who appeared to demonstrate relatively isolated impairment in visual imagery. Her cognitive function, including her performance on tests of semantic function, was at ceiling, apart from a deficit in visual memory. IM failed in tasks involving degraded stimuli, object decision involving reality judgments on normal animals, and drawings from memory. By contrast, she was able to match objects seen from an unfamiliar viewpoint and to perform tasks of semantic and visual association. We hypothesize that IM has a visual working memory deficit that impairs her ability to generate full visual representations of objects given their names, individual feature, or partial representations. The deficit appears to be the result of damage to connections between the right thalamus and the right temporal lobe. Our findings may help to clarify the role of the thalamus in the cortical selective engagement processes that underlie working memory. (JINS, 2008, 14, 902–911.)

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.

scholarly journals Unified Visual Working Memory without the Anterior Corpus Callosum

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2106
Author(s):  
Yair Pinto ◽  
Edward H.F. de Haan ◽  
Maria-Chiara Villa ◽  
Sabrina Siliquini ◽  
Gabriele Polonara ◽  
...  
Keyword(s):  
Working Memory ◽  
Corpus Callosum ◽  
Visual Working Memory ◽  
Visual Information ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Healthy Human ◽  
Visual Hemifield ◽  
The Right ◽  
Visual Hemifields

One of the most fundamental, and most studied, human cognitive functions is working memory. Yet, it is currently unknown how working memory is unified. In other words, why does a healthy human brain have one integrated capacity of working memory, rather than one capacity per visual hemifield, for instance. Thus, healthy subjects can memorize roughly as many items, regardless of whether all items are presented in one hemifield, rather than throughout two visual hemifields. In this current research, we investigated two patients in whom either most, or the entire, corpus callosum has been cut to alleviate otherwise untreatable epilepsy. Crucially, in both patients the anterior parts connecting the frontal and most of the parietal cortices, are entirely removed. This is essential, since it is often posited that working memory resides in these areas of the cortex. We found that despite the lack of direct connections between the frontal cortices in these patients, working memory capacity is similar regardless of whether stimuli are all presented in one visual hemifield or across two visual hemifields. This indicates that in the absence of the anterior parts of the corpus callosum working memory remains unified. Moreover, it is important to note that memory performance was not similar across visual fields. In fact, capacity was higher when items appeared in the left visual hemifield than when they appeared in the right visual hemifield. Visual information in the left hemifield is processed by the right hemisphere and vice versa. Therefore, this indicates that visual working memory is not symmetric, with the right hemisphere having a superior visual working memory. Nonetheless, a (subcortical) bottleneck apparently causes visual working memory to be integrated, such that capacity does not increase when items are presented in two, rather than one, visual hemifield.

scholarly journals Brain Processing of Complex Geometric Forms in a Visual Memory Task Increases P2 Amplitude

2020 ◽  
Vol 10 (2) ◽  
pp. 114
Author(s):  
Héctor A. Cepeda-Freyre ◽  
Gregorio Garcia-Aguilar ◽  
Jose R. Eguibar ◽  
Carmen Cortes
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Cognitive Processing ◽  
Visual Memory ◽  
Memory Load ◽  
Memory Task ◽  
Event Related Potentials ◽  
Brain Regions ◽  
Test Phase ◽  
Related Potentials

We study the cognitive processing of visual working memory in three different conditions of memory load and configuration change. Altering this features has been shown to alter the brain’s processing in memory tasks. Most studies dealing with this issue have used the verbal-phonological modality. We use complex geometric polygons to assess visual working memory in a modified change detection task. Three different types of backgrounds were used to manipulate memory loading and 18 complex geometric polygons to manipulate stimuli configuration. The goal of our study was to test whether the memory load and configuration affect the correct-recall ratios. We expected that increasing visual items loading and changing configuration of items would induce differences in working memory performance. Brain activity related to the task was assessed through event-related potentials (ERP), during the test phase of each trial. Our results showed that visual items loading and changing of item configuration affect working memory on test phase on ERP component P2, but does not affect performance. However frontal related ERP component—P3—was minimally affected by visual memory loading or configuration changing, supporting that working memory is related to a filtering processing in posterior brain regions.

scholarly journals Brain Substrates for Distinct Spatial Processing Components Contributing to Hemineglect in Humans

2021 ◽  
Vol 11 (12) ◽  
pp. 1584
Author(s):  
Yann Cojan ◽  
Arnaud Saj ◽  
Patrik Vuilleumier
Keyword(s):  
Visual Search ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Critical Role ◽  
Frontal Lobes ◽  
Spatial Processing ◽  
Spatial Tasks ◽  
Lesion Symptom Mapping ◽  
Cortical Regions ◽  
The Right

Several cortical and sub-cortical regions in the right hemisphere, particularly in the parietal and frontal lobes, but also in the temporal lobe and thalamus, are part of neural networks critically implicated in spatial and attentional functions. Damage to different sites within these networks can cause hemispatial neglect. The aim of this study was to identify the neural substrates of different spatial processing components that are known to contribute to neglect symptoms. Firstly, three different spatial tasks (visual search, bisection, and visual memory) were tested in 26 healthy controls. The fMRI results showed a differential activation of regions in the parietal and frontal lobes during bisection and visual search, respectively. Secondly, fMRI was used in 27 patients with focal right brain damage. Voxel-based lesion–symptom mapping was used to determine the relationships between specific sites of damage and the severity of deficits in these three spatial tasks. In the patients, we confirmed a critical role of the right lateral parietal cortex in bisection, but lesions in the frontal and temporal lobes were critical for visual search. These data support the existence of distinct components in spatial attentional processes that might be damaged to different degrees in neglect patients.

scholarly journals Age Differences in Hemispheric Lateralization in Spatial and Verbal Visual Working Memory

2019 ◽  
Author(s):  
Myriam C. Sander ◽  
Patrizia M. Maier ◽  
Natan Napiórkowski ◽  
Kathrin Finke ◽  
Thomas Töllner ◽  
...  
Keyword(s):  
Older Adults ◽  
Working Memory ◽  
Visual Working Memory ◽  
Cognitive Aging ◽  
Spatial Information ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Hemispheric Lateralization ◽  
Verbal Stimuli ◽  
The Right

AbstractDue to hemispheric specialization of the human brain, neural signatures of visual working memory (WM) performance are expected to differ between tasks involving verbal versus spatial memoranda. Theories of cognitive aging suggest a reduction of hemispheric specialization in older adults. Using behavioral and neural WM capacity markers, we assessed hemispheric lateralization in younger and older adults performing a spatial or verbal visual WM task. Participants encoded information presented in the left or right hemifield. We observed behavioral advantages for spatial stimuli processed in the right hemisphere and for verbal stimuli processed in the left hemisphere. While younger adults showed lateralization in both tasks, older adults showed lateralization only in the verbal task. Lateralization was assessed by the contralateral delay activity (CDA) on the neural level. CDA amplitudes displayed hemispheric lateralization for verbal versus spatial material, but this effect was age-invariant. While our findings support right-hemispheric specialization for spatial information maintenance, and left-hemispheric specialization for verbal information maintenance, we could not confirm a generalized reduction in hemispheric lateralization at older ages.

scholarly journals Visual and verbal working memory loads interfere with scene viewing

2019 ◽  
Author(s):  
Deborah Cronin ◽  
Candace Elise Peacock ◽  
John M. Henderson
Keyword(s):  
Working Memory ◽  
Eye Movements ◽  
Visual Working Memory ◽  
Verbal Memory ◽  
Visual Memory ◽  
Memory Load ◽  
Memory Task ◽  
Verbal Working Memory ◽  
Working Memory Load ◽  
Scene Viewing

Working memory is thought to be divided into distinct visual and verbal subsystems. Studies of visual working memory frequently use verbal working memory tasks as control conditions and/or use articulatory suppression to ensure visual load remains in visual memory. Using these verbal tasks relies on the assumption that the verbal working memory load will not interfere with the same processes as visual working memory. In the present study, participants maintained a visual or verbal working memory load while simultaneously viewing scenes. Because eye movements and visual working memory are closely linked, we anticipated the visual load would interfere with scene viewing (and vice versa), while the verbal load would not. Surprisingly, both visual and verbal memory loads interfered with scene viewing behavior, while scene viewing did not significantly interfere with performance on either memory task. These results suggest that a verbal working memory load can interfere with a visual task and contribute to the growing literature suggesting the visual and verbal subsystems of working memory are less distinct than previously thought. Our data also stands at odds with previous work suggesting that visual working memory is obligatorily recruited by saccadic eye movements.

The correlation between apraxia and neglect in the right hemisphere: A voxel-based lesion-symptom mapping study in 138 acute stroke patients

Cortex ◽  
2020 ◽  
Vol 132 ◽  
pp. 166-179
Author(s):  
Andrea Dressing ◽  
Markus Martin ◽  
Lena-Alexandra Beume ◽  
Dorothee Kuemmerer ◽  
Horst Urbach ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Right Hemisphere ◽  
Mapping Study ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
The Right
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