Near and far space: Understanding the neural mechanisms of spatial attention

Abstract

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Dissociating the neural mechanisms of distance and spatial reference frames

“…The role of rPPC in processing near space is in accordance with previous research (Bjoertomt et al, 2002;Halligan & Marshall, 1991;Lane et al, 2013;Mennemeier et al, 1992;Weiss et al, 2000), as is its relationship with egocentric processing (Committeri et al, 2004;Galati et al, 2000;Hillis et al, 2005;Medina et al, 2009;Neggers et al, 2006;Vallar et al, 1999). Neuropsychological research has indicated that the right hemisphere is involved in egocentric processing in near space (Iachini, Ruggiero, Conson & Trojano, 2013), although this finding was based on extensive fronto-parietal lesions in only four patients making it difficult to determine the precise brain area underlying their impairment .…”

“…Our previous work (Lane et al, 2013) supported the finding that rVO of the ventral stream is involved in far space processing but not near (Bjoertomt et al, 2002;Butler, Eskes & Vandorpe, 2004;Halligan & Marshall, 1991;Mennemeier et al, 1992;Shelton, Bowers & Heilman, 1990;Valdés-Conroy, Sebastián, Hinojosa, Romá & Santaniello, 2014;Vuilleumier et al, 1998;Weiss et al, 2000). Specifically, 16 Bjoertomt et al (2002) revealed a significant involvement of rVO in a landmark task in far space, which could be identified as an allocentric task albeit not involving visual search.…”

“…Conversely, rFEF is involved regardless of distance or frame of reference. Finally, despite previously demonstrating involvement of rVO in the detection of the presence of targets in far space (Lane et al, 2013), rVO may not be involved when a judgement about the spatial location of the target is required at either distance.…”

“…Coil selection was in accordance with previous TMS investigations of these regions (e.g. Lane et al, 2013, Mahayana et al, 2014. In all conditions the coil was held in place by the experimenter.…”

“…To that end, a recent transcranial magnetic stimulation (TMS) study using neurotypical participants and a common conjunction visual search task in both near 4 and far space supported the rPPC and rVO dichotomy, but found that right FEF (rFEF) was involved in both near and far space (Lane, Ball, Smith, Schenk & Ellison, 2013). The dependant measure used in that study was the speed of detection of a target amongst distractors; e.g., the target could be either present or absent.…”