Complementary localization and lateralization of orienting and motor attention

Abstract

It is widely agreed that the right posterior parietal cortex has a preeminent role in visuospatial and orienting attention. A number of lines of evidence suggest that although orienting and the preparation of oculomotor responses are dissociable from each other, the two are intimately related. If this is true, then it should be possible to identify other attentional mechanisms tied to other response modalities. We used repetitive transcranial magnetic stimulation (rTMS) to demonstrate the existence of a distinct anterior parietal mechanism of motor attention. The critical area for motor attention is anterior to the one concerned with orienting, and it is lateralized to the left hemisphere in humans.

Selective and interactive neural correlates of visual dimension changes and response changes

“…Dimension changes further elicited activation along the descending and horizontal segments of the intraparietal sulcus, whereas response changes led to activation in its ascending segment. This distribution is in good agreement with studies of visual attention shifts, both between locations and between features, which have consistently reported activation along the horizontal segment of the intraparietal sulcus (Corbetta et al, 1998;Gitelman et al, 1999;Lepsien and Pollmann, 2002;Liu et al, 2003;Pollmann and von Cramon, 2000;Pollmann et al, 2000b;Weidner et al, 2002;Yantis et al, 2003), and with studies of prehensile movements (Binkofski et al, 1998(Binkofski et al, , 1999; and it is consistent with studies of motor attention (Rushworth et al, 2001), which have reported activation along the ascending segment of the intraparietal sulcus and functional deficits following natural lesions or transcranial magnetic stimulation of this segment.…”

Visual Selection and Posterior Parietal Cortex: Effects of Repetitive Transcranial Magnetic Stimulation on Partial Report Analyzed by Bundesen's Theory of Visual Attention

“…This indicated that, for row displays with one target in each hemifield, right PPC rTMS (vs none) relatively worsened performance for reporting the left target ( p Ͻ 0.05), shifting performance even farther away from that for the corresponding nontargettarget array, whereas right PPC rTMS actually benefited performance for a right target in target-target rows ( p Ͻ 0.05), with right-target performance for these now approaching the level for the corresponding nontarget-target array. The worsened performance for the left target specifically in row target-target displays here, under right PPC rTMS, resembles the contralesional extinction (i.e., failure to report a contralesional target in the presence of an ipsilesional target) in many right parietal patients (Vuilleumier and Rafal, 2000;Driver and Vuilleumier, 2001), whereas the improvement for reporting the right target from row target-target displays may be reminiscent of improved performance for stimuli ipsilateral to the TMS in some previous work (Seyal et al, 1995;Oliveri et al, 1999;Rushworth et al, 2001), although note that the present effects did not apply for single-target conditions (see above) and may thus be more analogous to extinction.…”

“…The intensity/frequency of the rTMS was chosen to be well within the safety guidelines (Wassermann, 1998), whereas the timing and duration of the rTMS ensured that it should overlap with any critical processing in PPC (i.e., during and immediately after presentation of each brief visual display while participants performed the task). Such "on-line" magnetic stimulation, delivered in a small number of pulses (usually one to five) at frequencies of ϳ10 -50 Hz, time locked to discrete trials in a task, have been used to transiently disrupt functions of the brain region targeted with TMS in many previous studies (Day et al, 1989;Pascual-Leone et al, 1994;Oliveri et al, 1999;Rushworth et al, 2001;Bjoertomt et al, 2002;Campana et al, 2002). The effects of on-line TMS, as used here, can be thought of as transiently introducing neural "noise" into the area stimulated (for review, see Walsh and Cowey, 2000;Walsh and PascualLeone, 2003).…”

Hands up: Attentional prioritization of space near the hand.

“…The premotor cortex has a role in selecting movements, whereas the parietal cortex is involved with movement preparation and intention (Kalaska & Crammond, 1995;Rushworth, Ellison, & Walsh, 2001;Thoenissen, Zilles, & Toni, 2002). In sum, hand-centered, multimodal representations may predispose attention to regions near the hand, potentially for future actions.…”