TY - JOUR
T1 - Shifting attentional priorities
T2 - Control of spatial attention through hemispheric competition
AU - Szczepanski, Sara M.
AU - Kastner, Sabine
PY - 2013
Y1 - 2013
N2 - Regions of frontal and posterior parietal cortex are known to control the allocation of spatial attention across the visual field. However, the neural mechanisms underlying attentional control in the intact human brain remain unclear, with some studies supporting a hemispatial theory emphasizing a dominant function of the right hemisphere and others supporting an interhemispheric competition theory.We previously found neural evidence tosupport the latter account,in which topographically organized frontoparietal areas each generate a spatial bias, or "attentional weight," toward the contralateral hemifield, with the sum of the weights constituting the overall bias that can be exerted across visual space. Here, we used a multimodal approach consisting of functional magnetic resonance imaging (fMRI) of spatial attention signals, behavioral measures of spatial bias, and fMRI-guided single-pulse transcranial magnetic stimulation (TMS) to causally test this interhemispheric competition account. Across the group of fMRI subjects, we found substantial individual differences in the strengths of the frontoparietal attentional weights in each hemisphere, which predicted subjects' respective behavioral preferences when allocatingspatial attention,asmeasuredbyalandmark task. Using TMStointerfere with attentional processing within specific topographic frontoparietal areas, we then demonstrated that the attentional weights of individual subjects, and thus their spatial attention behavior, could be predictably shifted toward one visual field or the other, depending on the site of interference. The results of our multimodal approach, combined with an emphasis on neural and behavioral individual differences, provide compelling evidence that spatial attention is controlled through competitive interactions between hemispheres rather than a dominant right hemisphere in the intact human brain.
AB - Regions of frontal and posterior parietal cortex are known to control the allocation of spatial attention across the visual field. However, the neural mechanisms underlying attentional control in the intact human brain remain unclear, with some studies supporting a hemispatial theory emphasizing a dominant function of the right hemisphere and others supporting an interhemispheric competition theory.We previously found neural evidence tosupport the latter account,in which topographically organized frontoparietal areas each generate a spatial bias, or "attentional weight," toward the contralateral hemifield, with the sum of the weights constituting the overall bias that can be exerted across visual space. Here, we used a multimodal approach consisting of functional magnetic resonance imaging (fMRI) of spatial attention signals, behavioral measures of spatial bias, and fMRI-guided single-pulse transcranial magnetic stimulation (TMS) to causally test this interhemispheric competition account. Across the group of fMRI subjects, we found substantial individual differences in the strengths of the frontoparietal attentional weights in each hemisphere, which predicted subjects' respective behavioral preferences when allocatingspatial attention,asmeasuredbyalandmark task. Using TMStointerfere with attentional processing within specific topographic frontoparietal areas, we then demonstrated that the attentional weights of individual subjects, and thus their spatial attention behavior, could be predictably shifted toward one visual field or the other, depending on the site of interference. The results of our multimodal approach, combined with an emphasis on neural and behavioral individual differences, provide compelling evidence that spatial attention is controlled through competitive interactions between hemispheres rather than a dominant right hemisphere in the intact human brain.
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U2 - 10.1523/JNEUROSCI.4089-12.2013
DO - 10.1523/JNEUROSCI.4089-12.2013
M3 - Article
C2 - 23516306
AN - SCOPUS:84877100386
SN - 0003-4819
VL - 158
SP - 5411
EP - 5421
JO - Annals of Internal Medicine
JF - Annals of Internal Medicine
IS - 6
ER -