The role of the parietal cortex in visual attention—hemispheric asymmetries and the effects of learning: a magnetic stimulation study

Walsh, Vincent; Ellison, Amanda; Ashbridge, Elisabeth; Cowey, Alan

doi:10.1016/s0028-3932(98)00099-2

Cited by 87 publications

(56 citation statements)

References 11 publications

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“…In addition, our novel finding for right parietal stimulation agrees with the topography of right PPC (Medendorp et al 2003) and may have been missed in previous TMS studies (Smyrnis et al 2003) as the result of differences in methodology. In fact, such a pattern of hemispheric asymmetry was also observed in previous TMS studies that emphasized generally the importance of the right PPC in visuospatial and visual attentional tasks (Muri et al 2002;Rushworth et al 2001;Walsh et al 1999), whereas left PPC played a dominant role in limb movements (Rushworth et al 2001;Smyrnis et al 2003).…”

Section: Discussionsupporting

confidence: 81%

Hemispheric Asymmetry in Memory-Guided Pointing During Single-Pulse Transcranial Magnetic Stimulation of Human Parietal Cortex

Vesia¹,

Monteon²,

Sergio³

et al. 2006

Journal of Neurophysiology

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asymmetry in memory-guided pointing during single-pulse transcranial magnetic stimulation of human parietal cortex. J Neurophysiol 96: 3016 -3027, 2006. First published September 27, 2006 doi:10.1152/jn.00411.2006. Dorsal posterior parietal cortex (PPC) has been implicated through single-unit recordings, neuroimaging data, and studies of brain-damaged humans in the spatial guidance of reaching and pointing movements. The present study examines the causal effect of single-pulse transcranial magnetic stimulation (TMS) over the left and right dorsal posterior parietal cortex during a memory-guided "reach-to-touch" movement task in six human subjects. Stimulation of the left parietal hemisphere significantly increased endpoint variability, independent of visual field, with no horizontal bias. In contrast, right parietal stimulation did not increase variability, but instead produced a significantly systematic leftward directional shift in pointing (contralateral to stimulation site) in both visual fields. Furthermore, the same lateralized pattern persisted with left-hand movement, suggesting that these aspects of parietal control of pointing movements are spatially fixed. To test whether the right parietal TMS shift occurs in visual or motor coordinates, we trained subjects to point correctly to optically reversed peripheral targets, viewed through a left-right Dove reversing prism. After prism adaptation, the horizontal pointing direction for a given visual target reversed, but the direction of shift during right parietal TMS did not reverse. Taken together, these data suggest that induction of a focal current reveals a hemispheric asymmetry in the early stages of the putative spatial processing in PPC. These results also suggest that a brief TMS pulse modifies the output of the right PPC in motor coordinates downstream from the adapted visuomotor reversal, rather than modifying the upstream visual coordinates of the memory representation.

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Section: Discussionsupporting

confidence: 81%

Hemispheric Asymmetry in Memory-Guided Pointing During Single-Pulse Transcranial Magnetic Stimulation of Human Parietal Cortex

Vesia¹,

Monteon²,

Sergio³

et al. 2006

Journal of Neurophysiology

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“…However, the relation between perceptual and response learning may depend on numerous factors, such as object complexity or salience on the perceptual learning side and the number of response alternatives on the response learning side. Furthermore, perceptual learning can proceed much faster than in the present experiment and the contribution of parietal cortex may decrease rapidly 14 . Are object-response associations created equally fast under these circumstances?…”

contrasting

confidence: 45%

Shift of activity from attention to motor-related brain areas during visual learning

Pollmann

Maertens²

2006

E-Neuroforum

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Section: The Current Studymentioning

confidence: 99%

“…In the current study, visual context words and primes were used rather than auditory stimuli, the visual stimuli consisted of words rather than pictures 3 , semanticallyrelated items were used rather than referents 4 , and participants were given explicit instructions to search for related items. This explicit task has more in common with the search tasks used in studies of visual attention (e.g., Walsh et al, 1999).Right hemisphere dominance in spatial attention and visual search tasks is well established in the literature (see O'Shea et al, 2006, for a review). The right hemisphere advantage for spatial attention is especially prevalent in right-handed individuals, with 95% of these participants showing greater right cerebral perfusion during a spatial attention task (Floel et al, 2005).…”

mentioning

confidence: 99%

The divided visual world paradigm: Eye tracking reveals hemispheric asymmetries in lexical ambiguity resolution

Meyer¹,

Federmeier²

2008

Brain Research

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Eye tracking was combined with the visual half-field procedure to examine hemispheric asymmetries in meaning selection and revision. In two experiments, gaze was monitored as participants searched a four-word array for a target that was semantically related to a lateralized ambiguous or unambiguous prime. Primes were preceded by a related or unrelated centrally-presented context word. In Experiment 1, unambiguous primes were paired with concordant weakly-related context words and strongly-related targets that were similar in associative strength to discordant subordinate-related context words and dominant-related targets in the ambiguous condition. Context words and targets were reversed in Experiment 2. A parallel study involved the measurement of event-related potentials (ERPs; Meyer, A. M., and Federmeier, K. D., 2007. The effects of context, meaning frequency, and associative strength on semantic selection: Distinct contributions from each cerebral hemisphere. Brain Res. 1183, 91-108). Similar to the ERP findings, gaze revealed context effects for both visual fields/hemispheres when subordinate-related targets were presented: initial gaze revealed meaning activation when an unrelated context was utilized, whereas later gaze also revealed activation in the discordant context, indicating that meaning revision had occurred. However, eye tracking and ERP measures diverged when dominant-related targets were presented: for both visual fields/hemispheres, initial gaze indicated the presence of meaning activation in the discordant context, and, for the right hemisphere, discordant context information actually facilitated gaze relative to unrelated context information. These findings are discussed with respect to the activeness of the task and hemispheric asymmetries in the flexible use of context information. KeywordsLexical Ambiguity; Cerebral Hemispheres; Context Effect; Eye Tracking Most English words are ambiguous (Rodd, Gaskell, and Marslen-Wilson, 2004), having either multiple unrelated meanings (homonymy) or multiple related senses (polysemy). For example, the homonym bank can refer to a financial institution or the edge of a river, and the polysemous word lamb can refer to food or a living animal. Lexical ambiguity has been the subject of much research over the past several decades; many studies (e.g., Duffy et al., 1988;Simpson, Corresponding Author: Aaron M. Meyer, Beckman Institute, University of Illinois, 405 N. Mathews Ave., Urbana, IL 61801, meyeram@uiuc.edu, (217) 244-9638. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 1981;Swinney and Hakes, 1976;Ta...

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The role of the parietal cortex in visual attention—hemispheric asymmetries and the effects of learning: a magnetic stimulation study

Cited by 87 publications

References 11 publications

Hemispheric Asymmetry in Memory-Guided Pointing During Single-Pulse Transcranial Magnetic Stimulation of Human Parietal Cortex

Hemispheric Asymmetry in Memory-Guided Pointing During Single-Pulse Transcranial Magnetic Stimulation of Human Parietal Cortex

Shift of activity from attention to motor-related brain areas during visual learning

The divided visual world paradigm: Eye tracking reveals hemispheric asymmetries in lexical ambiguity resolution

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