Lane, A.R. and Ball, K. and Smith, D.T. and Schenk, T and Ellison, A. (2013) 'Near and far space : understanding the neural mechanisms of spatial attention.', Human brain mapping., 34 (2). pp. 356-366.
Visuospatial neglect is a multicomponent syndrome, and one dissociation reported is between neglect for near (peripersonal) and far (extrapersonal) space. Owing to patient heterogeneity and extensive lesions, it is difficult to determine the precise neural mechanisms underlying this dissociation using clinical methodology. In this study, transcranial magnetic stimulation was used to examine the involvement of three areas in the undamaged brain, while participants completed a conjunction search task in near and far space. The brain areas investigated were right posterior parietal cortex (rPPC), right frontal eye field (rFEF), and right ventral occipital cortex (rVO), each of which has been implicated in visuospatial processing. The results revealed a double dissociation, whereby rPPC was involved for search in near space only, whilst rVO only became necessary when the task was completed in far space. These data provide clear evidence for a dorsal and ventral dissociation between the processing of near and far space, which is compatible with the functional roles previously attributed to the two streams. For example, the involvement of the dorsal stream in near space reflects its role in vision for action, because it is within this spatial location that actions can be performed. The results also revealed that rFEF is involved in the processing of visual search in both near and far space and may contribute to visuospatial attention and/or the control of eye-movements irrespective of spatial frame. We discuss our results with respect to their clear ramifications for clinical diagnosis and neurorehabilitation.
|Keywords:||Spatial processing, Transcranial magnetic stimulation, Visual search.|
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||https://doi.org/10.1002/hbm.21433|
|Publisher statement:||This is the accepted version of the following article: Lane, A. R., Ball, K., Smith, D. T., Schenk, T. and Ellison, A. (2013), Near and far space: Understanding the neural mechanisms of spatial attention. Human Brain Mapping, 34(2): 356–366, which has been published in final form at http://dx.doi.org/10.1002/hbm.21433. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.|
|Date accepted:||26 July 2011|
|Date deposited:||20 November 2015|
|Date of first online publication:||February 2013|
|Date first made open access:||No date available|
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