scholarly journals Hemispheric antagonism in visuo-spatial neglect: A case study

1996 ◽  
Vol 2 (5) ◽  
pp. 412-418 ◽  
Author(s):  
John C. Marshall ◽  
Peter W. Halligan

AbstractWe report a case of severe visuo-spatial neglect consequent upon right-hemisphere stroke. At the time of testing, the patient had no visual field cut and no significant hemiparesis. Conventional testing on cancellation tasks with the right hand revealed reliable left neglect, but performance was significantly improved when the left hand was used. Investigations of (manual) line bisection showed normal performance with the right hand but right neglect when the left hand was used. Right neglect was also observed on a purely perceptual version of the line bisection task. We argue that the attentional vectors of the cerebral hemispheres can be modulated by (perceptual) task-demands and by (motorie) response demands. (JINS, 1996, 2, 412–418.)

2021 ◽  
Vol 11 (3) ◽  
pp. 376
Author(s):  
Carmelo Mario Vicario ◽  
Gabriella Martino ◽  
Alex Marcuzzo ◽  
Giuseppe Craparo

Neuroscience research links alexithymia, the difficulty in identifying and describing feelings and emotions, with left hemisphere dominance and/or right hemisphere deficit. To provide behavioral evidence for this neuroscientific hypothesis, we explored the relationship between alexithymia and performance in a line bisection task, a standard method for evaluating visuospatial processing in relation to right hemisphere functioning. We enrolled 222 healthy participants who completed a version of the 20-item Toronto Alexithymia Scale (TAS-20), which measures alexithymia, and were asked to mark (bisect) the center of a 10-cm horizontal segment. The results document a significant rightward shift in the center of the line in participants with borderline and manifest alexithymia compared with non-alexithymic individuals. The higher the TAS-20 score, the greater the rightward shift in the line bisection task. This finding supports the right hemisphere deficit hypothesis in alexithymia and suggests that visuospatial abnormalities may be an important component of this mental condition.


1998 ◽  
Vol 86 (3) ◽  
pp. 967-975 ◽  
Author(s):  
Brian K. V. Maraj ◽  
Digby Elliott ◽  
James Lyons ◽  
Eric A. Roy ◽  
Tamara Winchester

Two experiments were conducted to examine manual asymmetries in a one-dimensional aiming task. In Exp. 1, 10 right-handed adults slid a computer mouse 13 cm on a graphics tablet with both the right and left hands to targets of 3 different diameters. Under these conditions, the movement time for the right hand was significantly faster as expected. In Exp. 2, subjects performed similar movements to move a cursor 13 cm on a computer monitor. Thus the study was identical except the stimulus-response mapping was indirect. In this situation, there were no significant differences for either movement time or movement error between hands despite these performance measures indicating that target aiming was more difficult in Exp. 2. Because increases in task difficulty generally result in a greater advantage for the right hand, as indicated by Todor & Smiley, 1985, the present studies suggest that superiority of the right hand in aiming tasks may be diminished when spatial translation is required. Perhaps the spatial translation requires greater involvement of the right hemisphere, a process associated with manual advantage for the left hand, previously suggested by Roy and MacKenzie.


Author(s):  
Sherma Zacharias ◽  
Andrew Kirk

ABSTRACT:Background:Constructional impairment following left vs. right hemisphere damage has been extensively studied using drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects.Methods:Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs testResults:Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand.Conclusions:The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LHD is due to an elementary motor disturbance related to use of the non-dominant hand.


2020 ◽  
Vol 33 (4-5) ◽  
pp. 549-567 ◽  
Author(s):  
Andrea Ciricugno ◽  
Luca Rinaldi ◽  
Tomaso Vecchi ◽  
Lotfi B. Merabet ◽  
Zaira Cattaneo

Abstract Prior studies have shown that strabismic amblyopes do not exhibit pseudoneglect in visual line bisection, suggesting that the right-hemisphere dominance in the control of spatial attention may depend on a normally developing binocular vision. In this study, we aimed to investigate whether an abnormal binocular childhood experience also affects spatial attention in the haptic modality, thus reflecting a supramodal effect. To this aim, we compared the performance of normally sighted, strabismic and early monocular blind participants in a visual and a haptic line bisection task. In visual line bisection, strabismic individuals tended to err to the right of the veridical midpoint, in contrast with normally sighted participants who showed pseudoneglect. Monocular blind participants exhibited high variability in their visual performance, with a tendency to bisect toward the direction of the functioning eye. In turn, in haptic bisection, all participants consistently erred towards the left of the veridical midpoint. Taken together, our findings support the view that pseudoneglect in the visual and haptic modality relies on different functional and neural mechanisms.


1984 ◽  
Vol 59 (3) ◽  
pp. 933-934 ◽  
Author(s):  
James K. Maxwell ◽  
Fred Wise ◽  
Mary Pepping ◽  
Brenda D. Townes ◽  
John Peel ◽  
...  

Records from 495 psychiatric patients from two neuropsychology laboratories indicated the Fingertip Number Writing test shows a significant and reliable left-hand advantage within and between laboratories. While the left-hand advantage may reflect a right-hemisphere superiority for tactile-spatial processing, it is not possible to distinguish between right hemispheric functional superiority and practice effects between hands because the standard fingertip writing task always starts with the right hand.


Neurosurgery ◽  
2011 ◽  
Vol 69 (6) ◽  
pp. 1218-1231 ◽  
Author(s):  
Franck-Emmanuel Roux ◽  
Olivier Dufor ◽  
Valérie Lauwers-Cances ◽  
Leila Boukhatem ◽  
David Brauge ◽  
...  

Abstract BACKGROUND Cortical and subcortical electrostimulation mapping during awake brain surgery for tumor removal is usually used to minimize deficits. OBJECTIVE To use electrostimulation to study neuronal substrates involved in spatial awareness in humans. METHODS Spatial neglect was studied using a line bisection task in combination with electrostimulation mapping of the right hemisphere in 50 cases. Stimulation sites were identified with Talairach coordinates. The behavioral effects induced by stimulation, especially eye movements and deviations from the median, were quantified and compared with preoperative data and a control group. RESULTS Composite and highly individualized spatial neglect maps were generated. Both rightward and leftward deviations were induced, sometimes in the same patient but for different stimulation sites. Group analysis showed that specific and reproducible line deviations were induced by stimulation of discrete cortical areas located in the posterior part of the right superior and middle temporal gyri, inferior parietal lobe, and inferior postcentral and inferior frontal gyri (P > .05). Fiber tracking identified stimulated subcortical areas important to spare as sections of fronto-occipital and superior longitudinal II fascicles. According to preoperative and postoperative neglect battery tests, the specificity and sensitivity of intraoperative line bisection tests were 94% and 83%, respectively. CONCLUSION In humans, discrete cortical areas that are variable in location between individuals but mainly located within the right posterior Sylvian fissure sustain visuospatial attention specifically toward the contralateral or ipsilateral space direction. Line bisection mapping was found to be a reliable method for minimizing spatial neglect caused by brain tumor surgery.


1999 ◽  
Vol 31 (2) ◽  
pp. 221-231 ◽  
Author(s):  
ALFRED MEIER-KOLL

Endogenous ultradian rhythms with a periodicity of 2–3 hours operate separately in the right and left hemispheres of the human brain and modulate physiological functions, perception and cognition. Since sensory pathways from either hand terminate in the contralateral hemisphere, ultradian rhythms of the right and left brain can be monitored by variations in the tactile discrimination of the left and right hand, respectively. Thirteen right-handed German males were tested every 15 minutes for 8 hours. Time series of the tactile error rate determined for the right and left hands oscillate with significantly different ultradian periodicities. Whereas cycles in tactile discrimination of the right hand (left hemisphere) have a periodicity of about 2 hours, tactile discrimination of the left hand (right hemisphere) is modulated by longer periods of about 3 hours. This is interpreted in terms of the overall functional asymmetry of the human brain. Since the left brain is the specialized locus for verbal processing and the right brain for visual–spatial processing, lateralized ultradian rhythms operating in the hemispheres may provide a distinct frame for long-term timing of neuronal processes underlying semantic and spatial mapping of the environment. This is particularly important for interpreting biosocial behavioural rhythms seen in humans living under natural conditions.


1989 ◽  
Vol 68 (3) ◽  
pp. 767-778 ◽  
Author(s):  
Teresa Wilcox ◽  
R. Harter Kraft

20 normal, right-handed, familial dextral men performed (a) unimanual finger tapping, (b) encoding of schematic faces at three levels of difficulty (3, 5, and 7 faces), (c) verbal production, (d) concurrent tapping and verbal production, and (e) concurrent tapping and face encoding. Subsequent recognition of faces was disrupted more by concurrent left-hand tapping than by concurrent right-hand tapping, supporting both the hypothesis that the right hemisphere mediates face encoding in adults and Kinsbourne and Hicks' (1978) “functional cerebral distance principle.” Left- and right-hand tapping rate and variability were not asymmetrically affected by either verbal production or face encoding. While there was an increase in generalized interference effects on face encoding, the degree of asymmetry of the interference remained constant. In addition, as the difficulty of the memory task increased, variability of tapping rate decreased. This was discussed in terms of attention and automatic motor programming.


2008 ◽  
Vol 20 (1-2) ◽  
pp. 55-60 ◽  
Author(s):  
Jonathan T. Kleinman ◽  
Amitabh Gupta

Spatial processing is lateralized: the right hemisphere is optimized for perceiving global aspects of space (“seeing the forest”), while the left hemisphere specializes in perceiving local aspects of space (“seeing the trees”). However, less is known about how the information is shared across the hemispheres and which areas within the corpus callosum are required for transferring and integrating visuospatial information. Here, we report a 60 year old woman with a mass lesion in the splenium of the corpus callosum who demonstrated visuospatial processing deficits that were out-of-proportion to the rest of her neurological examination. Remarkably, in the Rey-Osterrieth Complex figure task, she copied with her left hand the outlines of the figure (global aspects), whereas with her right hand she drew the details of that figure (local aspects). While hemispheric lesions have demonstrated single dissociations of spatial processing, these results indicate that a lesion in the corpus callosum can produce a double dissociation for high-level spatial tasks, as local and global spatial perception are further dissociated with handedness. Interestingly, as little as the posterior third of the corpus callosum is required for proper visuospatial information transfer and integration, which provides important insight into the interhemispheric functional anatomy that underlies visuospatial perception.


2019 ◽  
Vol 12 (1) ◽  
pp. 111-119
Author(s):  
Ivanka V. Asenova ◽  
Yoanna R. Andonova-Tsvetanova

Eighty-eight Bulgarian children (range 5 – 7 years old), 40 left handers (18 boys) and 48 right handers (26 boys), completed line-bisection test one time with each hand. In accordance with previous studies the results show that the majority of children demonstrated deviation to the left of the true center with the left hand and to the right with the right hand, suggesting symmetrical neglect. Sex, handedness and their interaction had no main effect on mean percentage deviation scores at the group level, but only sex had a significant impact on the frequency of symmetrical neglect (p < .05), with higher one in girls than in boys.


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