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 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 The Right Hemisphere Is Responsible for the Greatest Differences in Human Brain Response to High-Arousing Emotional versus Neutral Stimuli: A MEG Study

2021 ◽  
Vol 11 (8) ◽  
pp. 960
Author(s):  
Mina Kheirkhah ◽  
Philipp Baumbach ◽  
Lutz Leistritz ◽  
Otto W. Witte ◽  
Martin Walter ◽  
...  
Keyword(s):  
Human Brain ◽  
Right Hemisphere ◽  
Emotional Stimuli ◽  
Brain Response ◽  
Whole Brain ◽  
Brain Responses ◽  
Cortical Regions ◽  
The Right ◽  
Healthy Participants

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.

scholarly journals Decreases in Frontal and Parietal Lobe Regional Cerebral Blood Flow Related to Habituation

1992 ◽  
Vol 12 (4) ◽  
pp. 546-553 ◽  
Author(s):  
Steven Warach ◽  
Ruben C. Gur ◽  
Raquel E. Gur ◽  
Brett E. Skolnick ◽  
Walter D. Obrist ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Parietal Lobe ◽  
Brain Activity ◽  
Inhalation Technique ◽  
Attentional Processes ◽  
Left Handed ◽  
Verbal Tasks ◽  
Spatial Tasks ◽  
Regional Specificity ◽  
The Right

We previously reported decreased mean CBF between consecutive resting conditions, ascribed to habituation. Here we address the regional specificity of habituation over three consecutive flow studies. Regional CBF (rCBF) was measured in 55 adults (12 right-handed men, 12 right-handed women, 14 left-handed men, 17 left-handed women), with the 133Xe inhalation technique, during three conditions: Resting, verbal tasks (analogies), and spatial tasks (line orientation). Changes in rCBF attributable to the cognitive tasks were eliminated by correcting these values to a resting equivalent. There was a progressive decrease in mean rCBF over time, reflecting habituation. This effect differed by region, with specificity at frontal (prefrontal, inferior frontal, midfrontal, superior frontal) and inferior parietal regions. In the inferior parietal region, habituation was more marked in the left than the right hemisphere. Right-handers showed greater habituation than did left-handers. There was no sex difference in global habituation, but males showed greater left whereas females showed greater right hemispheric habituation. The results suggest that habituation to the experimental setting has measurable effects on rCBF, which are differently lateralized for men and women. These effects are superimposed on task activation and are most pronounced in regions that have been implicated in attentional processes. Thus, regional decrement in brain activity related to habituation seems to complement attentional effects, suggesting a neural network for habituation reciprocating that for attention.

Corrigendum to “The right hemisphere is dominant in organization of visual search—A study in stroke patients” [Behav. Brain Res. 304 (2016) 71–79]

2017 ◽  
Vol 319 ◽  
pp. 234
Author(s):  
Antonia F. Ten Brink ◽  
J. Matthijs Biesbroek ◽  
Hugo J. Kuijf ◽  
Stefan Van der Stigchel ◽  
Quirien Oort ◽  
...  
Keyword(s):  
Visual Search ◽  
Right Hemisphere ◽  
Stroke Patients ◽  
The Right

scholarly journals Asymmetric TDP pathology in primary progressive aphasia with right hemisphere language dominance

Neurology ◽  
2018 ◽  
Vol 90 (5) ◽  
pp. e396-e403 ◽  
Author(s):  
Garam Kim ◽  
Shahrooz Vahedi ◽  
Tamar Gefen ◽  
Sandra Weintraub ◽  
Eileen H. Bigio ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Primary Progressive Aphasia ◽  
Cortical Atrophy ◽  
Progressive Aphasia ◽  
Language Dominance ◽  
Primary Progressive ◽  
Activated Microglia ◽  
Unbiased Stereology ◽  
Cortical Regions ◽  
The Right

ObjectiveTo quantitatively examine the regional densities and hemispheric distribution of the 43-kDa transactive response DNA-binding protein (TDP-43) inclusions, neurons, and activated microglia in a left-handed patient with right hemisphere language dominance and logopenic-variant primary progressive aphasia (PPA).MethodsPhosphorylated TDP-43 inclusions, neurons, and activated microglia were visualized with immunohistochemical and histologic methods. Markers were quantified bilaterally with unbiased stereology in language- and memory-related cortical regions.ResultsClinical MRI indicated cortical atrophy in the right hemisphere, mostly in the temporal lobe. Significantly higher densities of TDP-43 inclusions were present in right language-related temporal regions compared to the left or to other right hemisphere regions. The memory-related entorhinal cortex (ERC) and language regions without significant atrophy showed no asymmetry. Activated microglia displayed extensive asymmetry (R > L). A substantial density of neurons remained in all areas and showed no hemispheric asymmetry. However, perikaryal size was significantly smaller in the right hemisphere across all regions except the ERC. To demonstrate the specificity of this finding, sizes of residual neurons were measured in a right-handed case with PPA and were found to be smaller in the language-dominant left hemisphere.ConclusionsThe distribution of TDP-43 inclusions and microglial activation in right temporal language regions showed concordance with anatomic distribution of cortical atrophy and clinical presentation. The results revealed no direct relationship between density of TDP-43 inclusions and activated microglia. Reduced size of the remaining neurons is likely to contribute to cortical atrophy detected by MRI. These findings support the conclusion that there is no obligatory relationship between logopenic PPA and Alzheimer pathology.

Categorical and Metric Spatial Processes Distinguished by Task Demands and Practice

1999 ◽  
Vol 11 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Marie T. Banich ◽  
Kara D. Federmeier
Keyword(s):  
Visual Field ◽  
Right Hemisphere ◽  
Receptive Fields ◽  
Spatial Relations ◽  
Task Demands ◽  
Spatial Processing ◽  
Right Visual Field ◽  
Metric Distance ◽  
The Right ◽  
Categorical Spatial Relations

In this study we examined Kosslyn's (1987) claim that the right hemisphere exhibits a relative superiority for processing metric spatial relations, whereas the left hemisphere exhibits a relative superiority for processing categorical spatial relations. In particular, we examined whether some failures to observe strong visual field (VF) advantages in previous studies might be due to practice effects that allowed individuals to process tasks in alternative manners (e.g., to process a metric task using a categorical strategy). We used two versions of a task previously employed by Hellige and Michimata (1989) in which individuals judge the metric (distance) or categorical (above/below) spatial relations between a bar and a dot. In one version, the position of the bar was held static. In another, the bar's position varied. This manipulation prevented participants from using the computer screen as a reference frame, forcing them to compute the spatial relationships on the basis of the relevant items only (i.e., the bar and the dot). In the latter, but not the former version of the task we obtained evidence supporting Kosslyn's hypothesis, namely, a significant right visual field (RVF) advantage for categorical spatial processing and a trend toward a left visual field (LVF) advantage for metric spatial processing. Furthermore, the pattern of results for trials on which information was presented centrally (CVF trials) was similar to that observed on RVF trials, whereas the pattern for trials in which identical information was presented in each visual field (BVF trials) was similar to that observed on LVF trials. Such a pattern is consistent with Kosslyn's suggestion that categorical processing is better suited for cells with small receptive fields and metric processing for cells with larger receptive fields.

Hemispheric Specialization and Cognitive Development: Implications for Mathematics Education

1978 ◽  
Vol 9 (1) ◽  
pp. 20-32
Author(s):  
Grayson H. Wheatley ◽  
Robert Mitchell ◽  
Robert L. Frankland ◽  
Rosemarie Kraft
Keyword(s):  
Left Hemisphere ◽  
Hemispheric Asymmetry ◽  
Right Hemisphere ◽  
Mathematics Curriculum ◽  
Hemispheric Specialization ◽  
Brain Hemispheres ◽  
Spatial Tasks ◽  
Concrete Operational ◽  
The Right ◽  
Hemisphere Specialization

Evidence is presented for hemisphere specialization of the two brain hemispheres: the left hemisphere specialized for logico-analytic tasks and the right hemisphere, visuo-spatial tasks. A hypothesis is put forth for the emergence of the specialization that suggests a shift from predominant right hemisphere processing in infancy to predominant left hemisphere processing in adulthood. Results of the studies reviewed suggest the emergence of concrete-operational thought as the left hemisphere becomes capable of processing logical tasks. Electroencephalography seems particularly useful in determining specialization and mapping changes in hemispheric asymmetry. Implications for school mathematics curriculum are presented.

Emotional trauma and childhood amnesia

2003 ◽  
Vol 4 (2) ◽  
pp. 151-179
Author(s):  
Rhawn Joseph
Keyword(s):  
Visual Memory ◽  
Right Hemisphere ◽  
Emotional Memory ◽  
Wechsler Memory Scale ◽  
Facial Memory ◽  
Short Term Visual Memory ◽  
History Of ◽  
The Right ◽  
Early Trauma ◽  
Negative Memories

It has been reported that, on average, most adults recall first memories formed around age 3.5. In general, most first memories are positive. However, whether these first memories tend to be visual or verbal and whether the period for childhood amnesia (CA) is greater for visual or verbal or for positive versus negative memories has not been determined. Because negative, stressful experiences disrupt memory and can injure memory centers such as the hippocampus and amygdala, and since adults who were traumatized or abused during childhood (TA) reportedly suffer memory disturbances, it was hypothesized that those with a history of early trauma might suffer from a lengthier childhood amnesia and form their first recallable memories at a later age as compared to the general population (GP). Because the right hemisphere matures earlier than the language-dominant left hemisphere, and is dominant for visual and emotional memory, as well as the stress reponse, it was hypothesized that first recallable memories would be visual rather than verbal. Lastly, since stress can injure the brain and disrupt memory, it was hypothesized that the traumatized group would demonstrate memory and intellectual disturbances associated with right hemisphere injury as based on WAIS-R, Wechsler Memory Scale, and facial-memory testing. All hypotheses were supported. Positive and visual memories are formed before negative and verbal memories. TA CA offset, on average, is at age 6.1 versus 3.5 for GPs. TA PIQ (performance IQ), short-term visual memory, and facial memory were significantly reduced.

Three-dimensional neglect phenomena following right anterior choroidal artery infarction

1999 ◽  
Vol 5 (6) ◽  
pp. 567-571 ◽  
Author(s):  
ADRIANA KORI ◽  
DAVID S. GELDMACHER
Keyword(s):  
Right Hemisphere ◽  
Three Dimensional ◽  
Spatial Processing ◽  
Anterior Choroidal Artery ◽  
3 Dimensional ◽  
Spatial Dimensions ◽  
Anterior Choroidal ◽  
True Center ◽  
The Right ◽  
Choroidal Artery

Neglect in the horizontal and vertical axes of space has been observed after acute right anterior choroidal artery (AChA) lesions. How spatial processing is affected in the radial axis during the acute period following infarction in this region is unknown. We report the case of a 69-year-old man with acute left hemineglect and deficits in 3-dimensional spatial processing following right AChA infarction. His line bisections in 4 spatial conditions, oriented in the 3 primary axes of space, were compared with 6 control participants. The patient's bisections were different from true center and from control performance in all axes. His bisections were to the right, below, and distal to the arithmetic midpoint. This patient's bisection errors show a 3-dimensional neglect pattern following right AChA infarction, supporting the view that processing of all 3 spatial dimensions may be simultaneously disturbed following unilateral right hemisphere lesions. (JINS, 1999, 5, 567–571.)

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