scholarly journals Cortical Mechanisms for Reaches Versus Saccades: Progression of Effector-Specificity Through Target Memory to Movement Planning and Execution

2018 ◽  
Author(s):  
David C. Cappadocia ◽  
Simona Monaco ◽  
Ying Chen ◽  
J. Douglas Crawford
Keyword(s):  
Right Hemisphere ◽  
Motor Planning ◽  
Hemispheric Lateralization ◽  
Movement Planning ◽  
Time Courses ◽  
The Right ◽  
Conjunction Analysis ◽  
Reach Planning ◽  
Temporally Correlated ◽  
Target Memory

AbstractEffector-specific cortical mechanisms can be difficult to establish using fMRI, in part because low time resolution might temporally conflate different signals related to target representation, motor planning, and motor execution. Here, we used an event-related fMRI protocol and a cue-separation paradigm to temporally separate these three major sensorimotor stages for saccades vs. reaches. In each trial, subjects (N=12) 1) briefly viewed a target 4-7° left or right of midline fixation on a touchscreen, followed by an 8 second delay (effector-independent target memory phase), 2) were instructed by an auditory cue to perform a reach or a saccade, followed by a second delay of 8 seconds (effector-specific planning phase), and finally 3) were prompted to move by reaching-to-touch or performing a saccade towards the remembered target (effector-specific execution phase). Our analysis of saccade and reach activation (vs. a non-spatial control task) revealed modest effector-agnostic target memory activity (left AG, bilateral mIPS) followed by independent effector parietofrontal sites and time courses during the motor components of the task, specifically: more medial (pIPS, mIPS, M1, and PMd) activity during both reach planning and execution, and more lateral (mIPS, AG, and FEF) activity only during saccade execution. These motor activations were bilateral, with a left (contralateral) preference for reach. A conjunction analysis revealed that left mIPS and right AG, PCu, SPOC, FEF/PMv and LOTC showed activation for both saccades and reaches. Overall, effector-preference contrasts (reach vs. saccade) revealed significantly more parietofrontal activation for reaches than saccades during both planning and execution, with the exception of FEF. Cross-correlation of reach, saccade, and reach-saccade activation through time revealed correlated activation both within and across effectors in each hemisphere, but with a tendency toward higher correlations in the right hemisphere, especially between the eye and hand. These results demonstrate substantially independent but temporally correlated cortical networks for human eye, hand, and eye-hand control, that follow explicit spatiotemporal rules for effector-specific timing, medial-lateral distribution, and hemispheric lateralization.

Aprosodia and Its Treatment

2008 ◽  
Vol 18 (2) ◽  
pp. 66-72 ◽  
Author(s):  
Susan A. Leon ◽  
Amy D. Rodriguez
Keyword(s):  
Right Hemisphere ◽  
Hemispheric Lateralization ◽  
Motor Deficit ◽  
Emotional Communication ◽  
Emotional Information ◽  
Cognitive Linguistic ◽  
Linguistic Cues ◽  
Tone Of Voice ◽  
The Right

Abstract Aprosodia is a deficit in comprehending or expressing variations in tone of voice used to express both linguistic and emotional information. Affective aprosodia refers to a specific deficit in producing or comprehending the emotional or affective tones of voice. Aprosodia is most commonly associated with right hemisphere strokes; however, it may also result from other types of brain damage such as traumatic brain injury. Although research investigating hemispheric lateralization of prosody continues, there is strong evidence that most aspects of affective prosody are directed by the right hemisphere. Disorders of emotional communication can have a significant impact on quality of life for those affected and their families. However, there has been relatively little research regarding treatment for this disorder. Recently, 14 individuals were treated for affective aprosodia using two treatments, one based on cognitive-linguistic cues and the other on imitation of prosodic modeling. Most of the participants responded to at least one of the two treatments, and a refinement of the treatments are currently underway. Because researchers are finding support for the hypothesis that expressive aprosodia can result from a motor deficit, the refined treatment incorporates principles of motor learning to enhance imitation of prosodic models, as well as cognitive-linguistic cues.

scholarly journals The rodent hippocampus as a bilateral structure: A review of hemispheric lateralization

2017 ◽  
Author(s):  
Jake T. Jordan
Keyword(s):  
Brain Region ◽  
Spatial Information ◽  
Right Hemisphere ◽  
Neural Substrates ◽  
Hemispheric Lateralization ◽  
Hemispheric Differences ◽  
Functional Lateralization ◽  
Left And Right ◽  
The Right ◽  
Behavior And Cognition

AbstractThe left and right rodent hippocampi exhibit striking lateralization in some of the very neural substrates considered to be critical for hippocampal cognitive function. Despite this, there is an overwhelming lack of consideration for hemispheric differences in studies of the rodent hippocampus. Asymmetries identified so far suggest that a bilateral model of the hippocampus will be essential for an understanding of this brain region, and perhaps of the brain more widely. Although hypotheses have been proposed to explain how the left and right hippocampi contribute to behavior and cognition, these hypotheses have either been refuted by more recent studies or have been limited in the scope of data they explain. Here, I will first review data on human and rodent hippocampal lateralization. The implications of these data suggest that considering the hippocampus as a bilateral structure with functional lateralization will be critical moving forward in understanding the function and mechanisms of this brain region. In exploring these implications, I will then propose a hypothesis of the hippocampus as a bilateral structure. This discrete-continuous (DC) hypothesis proposes that the left and right hippocampi contribute to spatial memory and navigation in a complementary manner. Specifically, the left hemisphere stores spatial information as discrete, salient locations and that the right hemisphere represents space continuously, contributing to route computation and flexible spatial navigation. Consideration of hippocampal lateralization in designing future studies may provide insight into the function of the hippocampus and resolve debates concerning its function.

scholarly journals Upright or inverted, entire or exploded: right-hemispheric superiority in face recognition withstands multiple spatial manipulations

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1456 ◽  
Author(s):  
Giulia Prete ◽  
Daniele Marzoli ◽  
Luca Tommasi
Keyword(s):  
Face Recognition ◽  
Social Interactions ◽  
Face Processing ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Spatial Relations ◽  
Hemispheric Lateralization ◽  
Social Stimuli ◽  
Identity Recognition ◽  
The Right

Background.The ability to identify faces has been interpreted as a cerebral specialization based on the evolutionary importance of these social stimuli, and a number of studies have shown that this function is mainly lateralized in the right hemisphere. The aim of this study was to assess the right-hemispheric specialization in face recognition in unfamiliar circumstances.Methods.Using a divided visual field paradigm, we investigated hemispheric asymmetries in the matching of two subsequent faces, using two types of transformation hindering identity recognition, namely upside-down rotation and spatial “explosion” (female and male faces were fractured into parts so that their mutual spatial relations were left intact), as well as their combination.Results.We confirmed the right-hemispheric superiority in face processing. Moreover, we found a decrease of the identity recognition for more extreme “levels of explosion” and for faces presented upside-down (either as sample or target stimuli) than for faces presented upright, as well as an advantage in the matching of female compared to male faces.Discussion.We conclude that the right-hemispheric superiority for face processing is not an epiphenomenon of our expertise, because we are not often exposed to inverted and “exploded” faces, but rather a robust hemispheric lateralization. We speculate that these results could be attributable to the prevalence of right-handedness in humans and/or to early biases in social interactions.

scholarly journals Hemispheric Lateralization of Visuospatial Attention Is Independent of Language Production on Right-Handers: Evidence From Functional Near-Infrared Spectroscopy

2022 ◽  
Vol 12 ◽  
Author(s):  
Gaoding Jia ◽  
Guangfang Liu ◽  
Haijing Niu
Keyword(s):  
Picture Naming ◽  
Language Production ◽  
Near Infrared ◽  
Right Hemisphere ◽  
Naming Task ◽  
Visuospatial Attention ◽  
Hemispheric Lateralization ◽  
Cognitive Tasks ◽  
Functional Near Infrared Spectroscopy ◽  
The Right

It is well-established that visuospatial attention is mainly lateralized to the right hemisphere, whereas language production is mainly left-lateralized. However, there is a significant controversy regarding how these two kinds of lateralization interact with each other. The present research used functional near-infrared spectroscopy (fNIRS) to examine whether visuospatial attention is indeed right-lateralized, whereas language production is left-lateralized, and more importantly, whether the extent of lateralization in the visuospatial task is correlated with that in the task involving language. Specifically, fifty-two healthy right-handed participants participated in this study. Multiple-channel fNIRS technique was utilized to record the cerebral hemodynamic changes when participants were engaged in naming objects depicted in pictures (the picture naming task) or judging whether a presented line was bisected correctly (the landmark task). The degree of hemispheric lateralization was quantified according to the activation difference between the left and right hemispheres. We found that the picture-naming task predominantly activated the inferior frontal gyrus (IFG) of the left hemisphere. In contrast, the landmark task predominantly activated the inferior parietal sulcus (IPS) and superior parietal lobule (SPL) of the right hemisphere. The quantitative calculation of the laterality index also showed a left-lateralized distribution for the picture-naming task and a right-lateralized distribution for the landmark task. Intriguingly, the correlation analysis revealed no significant correlation between the laterality indices of these two tasks. Our findings support the independent hypothesis, suggesting that different cognitive tasks may engender lateralized processing in the brain, but these lateralized activities may be independent of each other. Meanwhile, we stress the importance of handedness in understanding the relationship between functional asymmetries. Methodologically, we demonstrated the effectiveness of using the multichannel fNIRS technique to investigate the hemispheric specialization of different cognitive tasks and their lateralization relations between different tasks. Our findings and methods may have important implications for future research to explore lateralization-related issues in individuals with neural pathologies.

scholarly journals Prism adaptation speeds reach initiation in the direction of the prism after-effect.

2021 ◽  
Author(s):  
Christopher Lee Striemer ◽  
Carley Borza
Keyword(s):  
Sensory Input ◽  
Right Hemisphere ◽  
Prism Adaptation ◽  
Spatial Neglect ◽  
Egocentric Reference Frame ◽  
After Effect ◽  
The Right ◽  
Reach Planning ◽  
Direction Opposite ◽  
Healthy Participants

Damage to the temporal-parietal cortex in the right hemisphere often leads to spatial neglect – a disorder in which patients are unable to attend to sensory input from their contralesional (left) side. Neglect has been associated with both attentional and premotor deficits. That is, in addition to having difficulty with attending to the left side, patients are often slower to initiate leftward vs. rightward movements (i.e., directional hypokinesia). Previous research has indicated that a brief period of adaptation to rightward shifting prisms can reduce symptoms of neglect by adjusting the patient’s movements leftward, towards the neglected field. Although prism adaptation has been shown to reduce spatial attention deficits in patients with neglect, very little work has examined the effects of prisms on premotor symptoms. In the current study, we examined this in healthy individuals using leftward shifting prisms to induce a rightward shift in the egocentric reference frame, similar to neglect patients prior to prism adaptation. Specifically, we examined the speed with which healthy participants initiated leftward and rightward reaches (without visual feedback) prior to and following adaptation to either 17° leftward (n=16) or 17° rightward (n=15) shifting prisms. Our results indicated that, following adaptation, participants were significantly faster to initiate reaches towards targets located in the direction opposite the prism shift. That is, participants were faster to initiate reaches to right targets following leftward prism adaptation, and were faster to initiate reaches to left targets following rightward prism adaptation. Overall these results are consistent with the idea that prism adaptation can influence the speed with which a reach can be planned toward a target in the direction opposite the prism shift, possibly through altering activity in neural circuits involved in reach planning.

The Lateralization of Attentional Functions in Action Video Game Players

2021 ◽  
Vol 68 (4) ◽  
pp. 198-205
Author(s):  
Xia Wu ◽  
Yan Zhang ◽  
Maojie Guo ◽  
Yunpeng Jiang ◽  
Xiaozhuang Wang
Keyword(s):  
Left Hemisphere ◽  
Video Game ◽  
Executive Control ◽  
Right Hemisphere ◽  
Hemispheric Lateralization ◽  
Functional Networks ◽  
Action Video Game ◽  
Game Players ◽  
The Right

Abstract. Action video game players (AVGPs) are proven to be significantly different from non-AVGPs (NAVGPs) in attention, which is proposed to be divided into three functional networks: alerting, orienting, and execution control. However, whether the hemispheric lateralization of attentional functions is influenced by the action video game is unclear. In the present study, we examined the lateralization of the three attentional functions in a group of AVGPs ( n = 33) compared to NAVGPs ( n = 34). The results showed that, relative to NAVGPs, the interactions between orienting and executive control in the left hemispheres of AVGPs were higher than those in the right hemisphere. Moreover, the correlations among the functions are much more sensitive in the left hemisphere. These results suggest significant left lateralization of the attentional functions in AVGPs.

Gesture and right hemisphere involvement in evaluating lecture material

Gesture ◽  
2004 ◽  
Vol 4 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Spencer D. Kelly ◽  
Leslie H. Goldsmith
Keyword(s):  
Cognitive Load ◽  
Right Hemisphere ◽  
Hemispheric Lateralization ◽  
Hand Gestures ◽  
Lecture Material ◽  
Processing Information ◽  
The Right ◽  
Load Conditions

This study investigated hemispheric lateralization in comprehending and evaluating lecture material with and without nonverbal hand gestures. Participants watched a lecture with and without gesture under conditions of cognitive load in the left or right hemisphere. There were no effects of gesture or load on lecture comprehension, but gesture and load influenced how participants evaluated the lecture. Specifically, presence of gesture significantly influenced participants’ affective evaluations of the lecturer in both load conditions. However, gesture influenced cognitive evaluations of the lecture material only when the right hemisphere was free from cognitive load. The results suggest that the right hemisphere may be specialized for processing information conveyed through hand gestures.

scholarly journals Differential Hemispheric Lateralization of Emotions and Related Display Behaviors: Emotion-Type Hypothesis

2021 ◽  
Vol 11 (8) ◽  
pp. 1034
Author(s):  
Elliott D. Ross
Keyword(s):  
Left Hemisphere ◽  
Positive Emotions ◽  
Right Hemisphere ◽  
Research Data ◽  
Hemispheric Lateralization ◽  
Social Emotions ◽  
Right Hemisphere Hypothesis ◽  
The Right ◽  
The Brain ◽  
Emotion Type

There are two well-known hypotheses regarding hemispheric lateralization of emotions. The Right Hemisphere Hypothesis (RHH) postulates that emotions and associated display behaviors are a dominant and lateralized function of the right hemisphere. The Valence Hypothesis (VH) posits that negative emotions and related display behaviors are modulated by the right hemisphere and positive emotions and related display behaviors are modulated by the left hemisphere. Although both the RHH and VH are supported by extensive research data, they are mutually exclusive, suggesting that there may be a missing factor in play that may provide a more accurate description of how emotions are lateralization in the brain. Evidence will be presented that provides a much broader perspective of emotions by embracing the concept that emotions can be classified into primary and social types and that hemispheric lateralization is better explained by the Emotion-type Hypothesis (ETH). The ETH posits that primary emotions and related display behaviors are modulated by the right hemisphere and social emotions and related display behaviors are modulated by the left hemisphere.

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 The Effect of Blindness on Spatial Asymmetries

2020 ◽  
Vol 10 (10) ◽  
pp. 662
Author(s):  
Luca Rinaldi ◽  
Andrea Ciricugno ◽  
Lotfi B. Merabet ◽  
Tomaso Vecchi ◽  
Zaira Cattaneo
Keyword(s):  
Mirror Symmetry ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Occipital Cortex ◽  
Visual Development ◽  
Hemispheric Lateralization ◽  
Spatial Processes ◽  
Spatial Tasks ◽  
Spatial Asymmetries ◽  
The Right

The human cerebral cortex is asymmetrically organized with hemispheric lateralization pervading nearly all neural systems of the brain. Whether the lack of normal visual development affects hemispheric specialization subserving the deployment of visuospatial attention asymmetries is controversial. In principle, indeed, the lack of early visual experience may affect the lateralization of spatial functions, and the blind may rely on a different sensory input compared to the sighted. In this review article, we thus present a current state-of-the-art synthesis of empirical evidence concerning the effects of visual deprivation on the lateralization of various spatial processes (i.e., including line bisection, mirror symmetry, and localization tasks). Overall, the evidence reviewed indicates that spatial processes are supported by a right hemispheric network in the blind, hence, analogously to the sighted. Such a right-hemisphere dominance, however, seems more accentuated in the blind as compared to the sighted as indexed by the greater leftward bias shown in different spatial tasks. This is possibly the result of the more pronounced involvement of the right parietal cortex during spatial tasks in blind individuals compared to the sighted, as well as of the additional recruitment of the right occipital cortex, which would reflect the cross-modal plastic phenomena that largely characterize the blind brain.

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