Bihemispheric Leftward Bias in a Visuospatial Attention-Related Network

Siman-Tov, Tali; Mendelsohn, Avi; Schönberg, Tom; Avidan, Galia; Podlipsky, Ilana; Pessoa, Luiz; Gadoth, Natan; Ungerleider, Leslie G.; Hendler, Talma

doi:10.1523/jneurosci.0599-07.2007

Cited by 119 publications

(98 citation statements)

References 38 publications

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“…In our data, cue and delay activation was more extensive in the right SMG than in the left. In the SPL, a bihemispheric leftward bias caused by right hemispheric dominance in the visuospatial network during passive fixation has been reported (35). Khonsari et al (36) found saccade preparatory signals (for left and right targets) only in the left PPC but found execution signals confined to the right PPC.…”

Section: Discussionmentioning

confidence: 95%

Space representation for eye movements is more contralateral in monkeys than in humans

Kagan

Iyer

Lindner

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Contralateral hemispheric representation of sensory inputs (the right visual hemifield in the left hemisphere and vice versa) is a fundamental feature of primate sensorimotor organization, in particular the visuomotor system. However, many higher-order cognitive functions in humans show an asymmetric hemispheric lateralizatione.g., right brain specialization for spatial processing-necessitating a convergence of information from both hemifields. Electrophysiological studies in monkeys and functional imaging in humans have investigated space and action representations at different stages of visuospatial processing, but the transition from contralateral to unified global spatial encoding and the relationship between these encoding schemes and functional lateralization are not fully understood. Moreover, the integration of data across monkeys and humans and elucidation of interspecies homologies is hindered, because divergent findings may reflect actual species differences or arise from discrepancies in techniques and measured signals (electrophysiology vs. imaging). Here, we directly compared spatial cue and memory representations for action planning in monkeys and humans using event-related functional MRI during a working-memory oculomotor task. In monkeys, cue and memory-delay period activity in the frontal, parietal, and temporal regions was strongly contralateral. In putative human functional homologs, the contralaterality was significantly weaker, and the asymmetry between the hemispheres was stronger. These results suggest an inverse relationship between contralaterality and lateralization and elucidate similarities and differences in human and macaque cortical circuits subserving spatial awareness and oculomotor goal-directed actions.BOLD signal | event-related functional MRI | brain evolution | delayed saccades | lateralization

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Section: Discussionmentioning

confidence: 95%

Space representation for eye movements is more contralateral in monkeys than in humans

Kagan

Iyer

Lindner

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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“…The model proposed by Rueckert et al refers to a leftward attentional bias generated by spatial attention mechanisms located in the right hemisphere. This leftward attentional bias underlies most theories of pseudoneglect (Bultitude & Aimola-Davies, 2006;Nicholls & Roberts, 2002) and the neural/cognitive models that underlie them (Siman-Tov et al, 2007;Thiebaut de Schotten et al, 2011). Rueckert et al (2002) also discussed the relative under-and overestimations of lines of different lengths.…”

Section: Discussionmentioning

confidence: 96%

“…As a result, the act of spatial processing during line bisection precipitates a bias of attention to the left hemispace, causing the features of the stimulus on that side to appear more salient. More recent models have proposed a revised activation-orientation model, in which pseudoneglect and neglect are explained in terms of asymmetric interhemispheric neural activation and connectivity (Siman-Tov et al, 2007). Neuroanatomical support for these models has come from a diffusion tensor-imaging study by Thiebaut de Schotten et al (2011), which showed that individual differences in the strengths of pseudoneglect were related to asymmetries in the neural pathways connecting the ventral and dorsal attentional systems in the right hemisphere.…”

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confidence: 99%

An investigation of the mechanisms underlying the effects of viewing distance and stimulus length on attentional asymmetries during line bisection

Nicholls

Beckman

Churches

2016

Atten Percept Psychophys

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Clinical neglect patients overattend to stimuli on their right, whereas the general population overattend to the left (pseudoneglect). Both phenomena are affected by viewing distance, whereby the attentional biases are attenuated as the stimulus moves from near to far space. Both are also affected by stimulus length and reduce in strength, or even reverse (the crossover effect), as length decreases. To gain an insight into the cognitive/neural mechanisms that underlie the effects of viewing distance and stimulus length, in two experiments we examined the interaction between the variables. In Experiment 1 we asked university students (n = 20) to perform a horizontal landmark bisection task with lines presented at varying lengths (1.2°, 6.3°, and 18.4°of viewing angle) and distances (450 and 1,350 mm). A crossover effect and pseudoneglect were observed for the short and the long lines, respectively. An effect of viewing distance was only observed for long lines. Experiment 2 was the same, except that the lines were rotated to form vertical lines. No crossover effect was observed for the short lines, but an upward bias was observed for the long lines. Once again, an effect of viewing distance was only apparent for the long lines. These results demonstrate that the crossover effect is not a general property of short lines and is specific to the horizontal dimension. Models of crossover therefore need to incorporate processes related to left-right asymmetries. The results also demonstrate that viewing distance only affects long lines, and that this happens irrespective of orientation. A model of viewing distance is discussed that incorporates a right hemisphere mechanism specialized for an interaction between the ventral and dorsal streams.

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“…As the task used in the current study required simple button press responses and keyboard responses evoke a minimal amount of motor movement (i.e., McCourt & Olafson, 1997), pre-motor and motor biases do not provide an adequate explanation for the leftward bias either. Lateral asymmetries in cerebral activation are suggested to underlie the leftward bias (Schiff & Truchon, 1993), as the right hemisphere is primarily responsible for spatial attention (Corbetta et al, 1995;Posner & Petersen, 1990;Siman-Tov et al, 2007, but c.f. Giesbrecht, Kingstone, Handy, Hopfinger, & Mangun, 2006.…”

Section: Discussionmentioning

confidence: 99%

“…As the right hemisphere, specifically the posterior parietal area, is primarily responsible for spatial attention (e.g., Corbetta et al, 1995;Posner & Petersen, 1990;Posner & Rothbart, 2007), attention is preferentially directed toward the left side of space. This suggestion has been supported by neuroimaging data demonstrating that visuospatial attention networks are more activated by information in the left VF (Siman-Tov et al, 2007). Further, neuroimaging data indicate that the right hemisphere is more active during line bisection and landmark tasks (Bjoertomt et al, 2002;Çiçek et al, 2009;Fink et al, 2000;Fink et al, 2001;Foxe et al, 2003).…”

Section: Introductionmentioning

confidence: 87%

Upper and lower visual field differences in perceptual asymmetries

Elias

2011

Brain Research

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Neurologically normal individuals show a leftward spatial bias and tend to collide with objects on the right side more frequently than on the left. The upper visual field is associated with extrapersonal space, and mediated by the ventral stream through parvocellular projections.The lower visual field is associated with peripersonal space, and mediated by the dorsal stream through magnocellular projections. Upper and lower visual field differences have been observed in perceptual asymmetries but results have been mixed. Object-and space-based coordinates also both influence the leftward bias; however their relative contributions are unknown as similar spatial conditions are often collapsed across. More left-side collisions emerged on a route following task in the lower visual field and more right-side collisions were seen in the upper visual field (Thomas, Stuckel, Gutwin, & Elias, 2009). Left-handers made more right-side collisions in the central condition, whereas right-handers showed no bias. Leftward biases on the greyscales task were stronger in the lower visual field; however no distance-based differences were observed (Thomas & Elias, 2010). A stronger spatial bias was found on the greyscales task, whereas a stronger object-based bias was found on the object luminosity task (Thomas & Elias, in press). When individual spatial conditions were examined, the image chosen most often was always located in the lower field. Stimulus type and spatial location interacted to determine which coordinate type contributes more strongly to leftward biases. We also found that the leftward bias on the greyscales task was stronger in the lower visual field during prolonged presentation and in the upper visual field during brief presentation. A global motion task was created to preferentially engage magnocellular projections to the dorsal stream. Isoluminant red/green and blue/yellow colour tasks, which preferentially engage parvocellular projections to the ventral stream, were also created. Leftward biases were seen on the greyscales and motion tasks. On an isoluminant colour task, biases were significantly weakened, suggesting

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Bihemispheric Leftward Bias in a Visuospatial Attention-Related Network

Cited by 119 publications

References 38 publications

Space representation for eye movements is more contralateral in monkeys than in humans

Space representation for eye movements is more contralateral in monkeys than in humans

An investigation of the mechanisms underlying the effects of viewing distance and stimulus length on attentional asymmetries during line bisection

Upper and lower visual field differences in perceptual asymmetries

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