scholarly journals Representations of Facial Identity in the Left Hemisphere Require Right Hemisphere Processing

2012 ◽  
Vol 24 (4) ◽  
pp. 1006-1017 ◽  
Author(s):  
Sara C. Verosky ◽  
Nicholas B. Turk-Browne
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Right Visual Field ◽  
Fusiform Face Area ◽  
Identity Information ◽  
Facial Identity ◽  
Face Area ◽  
The Right ◽  
Fmri Adaptation

A quintessential example of hemispheric specialization in the human brain is that the right hemisphere is specialized for face perception. However, because the visual system is organized contralaterally, what happens when faces appear in the right visual field and are projected to the nonspecialized left hemisphere? We used divided field presentation and fMRI adaptation to test the hypothesis that the left hemisphere can recognize faces, but only with support from the right hemisphere. Consistent with this hypothesis, facial identity adaptation was observed in the left fusiform face area when a face had previously been processed by the right hemisphere, but not when it had only been processed by the left hemisphere. These results imply that facial identity information is transferred from the right hemisphere to the left hemisphere, and that the left hemisphere can represent facial identity but is less efficient at extracting this information by itself.

scholarly journals Neural Tuning for Face Wholes and Parts in Human Fusiform Gyrus Revealed by fMRI Adaptation

2010 ◽  
Vol 104 (1) ◽  
pp. 336-345 ◽  
Author(s):  
Alison Harris ◽  
Geoffrey Karl Aguirre
Keyword(s):  
Functional Mri ◽  
Holistic Processing ◽  
Fusiform Face Area ◽  
Single Population ◽  
Face Area ◽  
Neural Populations ◽  
The Face ◽  
Adaptation Response ◽  
The Right ◽  
Fmri Adaptation

Although the right fusiform face area (FFA) is often linked to holistic processing, new data suggest this region also encodes part-based face representations. We examined this question by assessing the metric of neural similarity for faces using a continuous carryover functional MRI (fMRI) design. Using faces varying along dimensions of eye and mouth identity, we tested whether these axes are coded independently by separate part-tuned neural populations or conjointly by a single population of holistically tuned neurons. Consistent with prior results, we found a subadditive adaptation response in the right FFA, as predicted for holistic processing. However, when holistic processing was disrupted by misaligning the halves of the face, the right FFA continued to show significant adaptation, but in an additive pattern indicative of part-based neural tuning. Thus this region seems to contain neural populations capable of representing both individual parts and their integration into a face gestalt. A third experiment, which varied the asymmetry of changes in the eye and mouth identity dimensions, also showed part-based tuning from the right FFA. In contrast to the right FFA, the left FFA consistently showed a part-based pattern of neural tuning across all experiments. Together, these data support the existence of both part-based and holistic neural tuning within the right FFA, further suggesting that such tuning is surprisingly flexible and dynamic.

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.

scholarly journals Handedness Does Not Impact Inhibitory Control, but Movement Execution and Reactive Inhibition Are More under a Left-Hemisphere Control

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1602
Author(s):  
Christian Mancini ◽  
Giovanni Mirabella
Keyword(s):  
Left Hemisphere ◽  
Inhibitory Control ◽  
Right Hemisphere ◽  
Dominant Role ◽  
Hemispheric Specialization ◽  
Arm Movement ◽  
Proactive Inhibition ◽  
Stop Signal Task ◽  
The Right

The relationship between handedness, laterality, and inhibitory control is a valuable benchmark for testing the hypothesis of the right-hemispheric specialization of inhibition. According to this theory, and given that to stop a limb movement, it is sufficient to alter the activity of the contralateral hemisphere, then suppressing a left arm movement should be faster than suppressing a right-arm movement. This is because, in the latter case, inhibitory commands produced in the right hemisphere should be sent to the other hemisphere. Further, as lateralization of cognitive functions in left-handers is less pronounced than in right-handers, in the former, the inhibitory control should rely on both hemispheres. We tested these predictions on a medium-large sample of left- and right-handers (n = 52). Each participant completed two sessions of the reaching versions of the stop-signal task, one using the right arm and one using the left arm. We found that reactive and proactive inhibition do not differ according to handedness. However, we found a significant advantage of the right versus the left arm in canceling movements outright. By contrast, there were no differences in proactive inhibition. As we also found that participants performed movements faster with the right than with the left arm, we interpret our results in light of the dominant role of the left hemisphere in some aspects of motor control.

Electroencephalographic Activity in a Flanker Interference Task Using Japanese Orthography

2002 ◽  
Vol 14 (7) ◽  
pp. 971-979 ◽  
Author(s):  
Shuhei Yamaguchi ◽  
Genya Toyoda ◽  
Jiang Xu ◽  
Shotai Kobayashi ◽  
Avishai Henik
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Late Phase ◽  
Right Visual Field ◽  
Interference Effects ◽  
Interference Task ◽  
Dorsolateral Prefrontal ◽  
The Right

The neural activities for color word interference effects were investigated using event-related brain potentials (ERPs) recorded in a flanker-type interference task. Kanji words (Japanese morphograms) and kana words (Japanese phono-grams) were used as the flanker stimuli to obtain insights about hemispheric specialization for processing two types of Japanese orthographies. Interference effects in reaction time were larger when kanji words were presented in the left visual field and when kana words were in the right visual field. ERPs were modulated by the incongruent flankers, which generated a negative ERP component with the different onset and offset depending on flanker attributes. Consistent with the behavioral data, the interference-related negativity was observed for kanji words presented in the left visual field and for kana words in the right visual field. The negativity distributed maximally over the fronto-central site. The early part of the negativity distributed strongly over the frontal midline area, whereas it extended bilaterally over the frontal area in the late phase. The present results support the view of preferential processing of kanji in the right hemisphere and that of kana in the left hemisphere. The temporal profile of scalp topographies for the interference-related neural activity suggests that the medial and dorsolateral prefrontal regions may be involved in maintaining attentional set and conflict resolution.

Right Hemisphere Memory Bias Does Not Extend to Involuntary Memories for Negative Scenes

Perception ◽  
2021 ◽  
Vol 50 (1) ◽  
pp. 27-38
Author(s):  
Ella K. Moeck ◽  
Nicole A. Thomas ◽  
Melanie K. T. Takarangi
Keyword(s):  
Visual Field ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Fields ◽  
Memory Bias ◽  
Right Visual Field ◽  
Hemispheric Differences ◽  
Involuntary Memory ◽  
Involuntary Memories ◽  
The Right

Attention is unequally distributed across the visual field. Due to greater right than left hemisphere activation for visuospatial attention, people attend slightly more to the left than the right side. As a result, people voluntarily remember visual stimuli better when it first appears in the left than the right visual field. But does this effect—termed a right hemisphere memory bias—also enhance involuntary memory? We manipulated the presentation location of 100 highly negative images (chosen to increase the likelihood that participants would experience any involuntary memories) in three conditions: predominantly leftward (right hemisphere bias), predominantly rightward (left hemisphere bias), or equally in both visual fields (bilateral). We measured subsequent involuntary memories immediately and for 3 days after encoding. Contrary to predictions, biased hemispheric processing did not affect short- or long-term involuntary memory frequency or duration. Future research should measure hemispheric differences at retrieval, rather than just encoding.

Functional Hemispheric Asymmetry and Belief in ESP: Towards a “Neuropsychology of Belief”

1993 ◽  
Vol 77 (3_suppl) ◽  
pp. 1299-1308 ◽  
Author(s):  
Peter Brugger ◽  
Alex Gamma ◽  
René Muri ◽  
Markus Schafer ◽  
Kirsten I. Taylor
Keyword(s):  
Visual Field ◽  
Lexical Decision ◽  
Left Hemisphere ◽  
Hemispheric Asymmetry ◽  
Right Hemisphere ◽  
Right Visual Field ◽  
Decision Task ◽  
Verbal Tasks ◽  
Hemisphere Dominance ◽  
The Right

30 right-handed subjects were given a lateralized tachistoscopic lexical-decision task. Subjects' belief in extrasensory perception (ESP) was assessed with a single six-point scale; 16 subjects were designated as believers in ESP and 14 subjects as nonbelievers. Believers in ESP did not exhibit a hemispheric asymmetry for the task while nonbelievers exhibited the expected right visual-field/left-hemisphere dominance documented in the literature. Believers' lack of asymmetry was not caused by an impaired left-hemisphere performance but rather by a significantly enhanced lexical-decision accuracy in the left visual field/right hemisphere compared to nonbelievers. These results are compatible with previous studies indicating a correlation between belief in ESP and a bias for right-hemisphere processing. Moreover, the results are relevant for a discussion of an association between paranormal beliefs and schizotypy: highly schizotypal individuals are not only particularly prone to believe in ESP but are also known to show an attenuation of hemispheric asymmetries in lateralized verbal tasks due to an enhanced contribution of the right hemisphere. We suggest that the neurological basis of delusion-like beliefs may involve a release of right-hemisphere function from left-hemisphere control and sketch the focus of research for a future “neuropsychology of belief.”

Monitoring the Visual World: Hemispheric Asymmetries and Subcortical Processes in Attention

1994 ◽  
Vol 6 (3) ◽  
pp. 267-275 ◽  
Author(s):  
G. R. Mangun ◽  
S. J. Luck ◽  
R. Plager ◽  
W. Loftus ◽  
S. A. Hillyard ◽  
...  
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Reaction Times ◽  
Attentional Deficits ◽  
Cortical Level ◽  
Visual Hemifield ◽  
Spatial Cuing ◽  
The Right ◽  
Subsequent Target

Hemispheric specialization and subcortical processes in visual anention were investigated in callosotomy (split-brain) patients by measuring reaction times to lateralized stimuli in a spatial cuing paradigm. Cuing effects were obtained for targets presented to the right hemisphere (left visual hemifield) but not for those presented to the left hemisphere. These cuing effects were manifest as faster reaction times when the cue correctly indicated the location of the subsequent target (valid trials), as compared to trials in which the cue and target appeared in opposite hemifields (invalid trials). This pattern suggests that the right hemisphere allocated attention to cued locations in either visual hemifield, whereas the left hemisphere allocated attention predominantly to the right hemifield. This finding is consistent with a body of evidence from studies in patients with cortical lesions who display different attentional deficits for right versus left hemisphere damage. Because the present pattern occurs in patients whose cerebral hemispheres are separated at the cortical level, it suggests that right hemisphere attentional allocation to events in the ipsilateral visual half-field is mediated in part via intact subcortical systems.

Variable Left-hemisphere Language and Orthographic Lateralization Reduces Right-hemisphere Face Lateralization

2015 ◽  
Vol 27 (5) ◽  
pp. 913-925 ◽  
Author(s):  
Eva M. Dundas ◽  
David C. Plaut ◽  
Marlene Behrmann
Keyword(s):  
Left Hemisphere ◽  
Face Processing ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Neural Systems ◽  
Discrimination Accuracy ◽  
Left Handed ◽  
Representational Space ◽  
The Right ◽  
Interactive Account

It is commonly believed that, in right-handed individuals, words and faces are processed by distinct neural systems: one in the left hemisphere (LH) for words and the other in the right hemisphere (RH) for faces. Emerging evidence suggests, however, that hemispheric selectivity for words and for faces may not be independent of each other. One recent account suggests that words become lateralized to the LH to interact more effectively with language regions, and subsequently, as a result of competition with words for representational space, faces become lateralized to the RH. On this interactive account, left-handed individuals, who as a group show greater variability with respect to hemispheric language dominance, might be expected to show greater variability in their degree of RH lateralization of faces as well. The current study uses behavioral measures and ERPs to compare the hemispheric specialization for both words and faces in right- and left-handed adult individuals. Although both right- and left-handed groups demonstrated LH over RH superiority in discrimination accuracy for words, only the right-handed group demonstrated RH over LH advantage in discrimination accuracy for faces. Consistent with this, increased right-handedness was related to an increase in RH superiority for face processing, as measured by the strength of the N170 ERP component. Interestingly, the degree of RH behavioral superiority for face processing and the amplitude of the RH N170 for faces could be predicted by the magnitude of the N170 ERP response to words in the LH. These results are discussed in terms of a theoretical account in which the typical RH face lateralization fails to emerge in individuals with atypical language lateralization because of weakened competition from the LH representation of words.

The nature of hemispheric specialization in man

1981 ◽  
Vol 4 (1) ◽  
pp. 51-63 ◽  
Author(s):  
J. L. Bradshaw ◽  
N. C. Nettleton
Keyword(s):  
Left Hemisphere ◽  
Temporal Order ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Time Dependent ◽  
Cerebral Lateralization ◽  
Verbal Processing ◽  
Special Cases ◽  
The One ◽  
The Right

AbstractThe traditional verbal/nonverbal dichotomy is inadequate for completely describing cerebral lateralization. Musical functions are not necessarily mediated by the right hemisphere; evidence for a specialist left-hemisphere mechanism dedicated to the encoded speech signal is weakening, and the right hemisphere possesses considerable comprehensional powers. Right-hemisphere processing is often said to be characterized by holistic or gestalt apprehension, and face recognition may be mediated by this hemisphere partly because of these powers, partly because of the right hemisphere's involvement in emotional affect, and possibly through the hypothesized existence of a specialist face processor or processors in the right. The latter hypothesis may, however, suffer the same fate as the one relating to a specialist encodedness processor for speech in the left. Verbal processing is largely the province of the left because of this hemisphere's possession of sequential, analytic, time-dependent mechanisms. Other distinctions (e.g., focal/diffuse and serial/parallel) are special cases of an analytic/holistic dichotomy. More fundamentally, however, the left hemisphere is characterized by its mediation of discriminations involving duration, temporal order, sequencing, and rhythm, at thesensory(tactual, visual, and, above all, auditory) level, and especially at themotorlevel (for fingers, limbs, and, above all, the speech apparatus). Spatial aspects characterize the right, the mapping of exteroceptive body space, and the positions of fingers, limbs, and perhaps articulators, with respect to actual and target positions. Thus there is a continuum of function between the hemispheres, rather than a rigid dichotomy, the differences being quantitative rather than qualitative, of degree rather than of kind.

Evoked Potential Correlates of Recovery from Aphasia after Focal Left Hemisphere Injury in Adults

Neurosurgery ◽  
1984 ◽  
Vol 14 (4) ◽  
pp. 412-415 ◽  
Author(s):  
C. Papanicolaou Andrew ◽  
S. Levin Harvey ◽  
M. Eisenberg Howard
Keyword(s):  
Left Hemisphere ◽  
Verbal Memory ◽  
Evoked Potential ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Memory Task ◽  
Normal Subjects ◽  
Hemispheric Activation ◽  
Cerebral Reorganization ◽  
The Right

Abstract An evoked potentials (EPs) paradigm that has been effective in demonstrating asymmetries in hemispheric activation during cognitive tasks was used to assess cerebral reorganization for language in recovered aphasics. Cortical click EPs were recorded bilaterally in normal volunteers, recovered aphasics who had sustained focal left hemisphere injury, and nonaphasic patients with diffuse injuries during a control condition of attending only to the click and during a verbal memory task. During that task, EP amplitude attenuation occurred in the left hemisphere for the normal subjects and the nonaphasic patients and in the right hemisphere for the recovered aphasics. These contrasting asymmetries in hemispheric activation suggest that a shift of hemispheric specialization for verbal processing contributes to the recovery of linguistic competence in adult aphasics.

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