Studying the Role of Human Parietal Cortex in Visuospatial Attention with Concurrent TMS-fMRI.
2702 - 2711.
Combining transcranial magnetic stimulation (TMS) with concurrent functional magnetic resonance imaging (fMRI) allows study of how local brain stimulation may causally affect activity in remote brain regions. Here, we applied bursts of high- or low-intensity TMS over right posterior parietal cortex, during a task requiring sustained covert visuospatial attention to either the left or right hemifield, or in a neutral control condition, while recording blood oxygenation-level-dependent signal with a posterior MR surface coil. As expected, the active attention conditions activated components of the well-described "attention network," as compared with the neutral baseline. Also as expected, when comparing left minus right attention, or vice versa, contralateral occipital visual cortex was activated. The critical new finding was that the impact of high- minus low-intensity parietal TMS upon these visual regions depended on the currently attended side. High- minus low-intensity parietal TMS increased the difference between contralateral versus ipsilateral attention in right extrastriate visual cortex. A related albeit less pronounced pattern was found for left extrastriate visual cortex. Our results confirm that right human parietal cortex can exert attention-dependent influences on occipital visual cortex and provide a proof of concept for the use of concurrent TMS-fMRI in studying how remote influences can vary in a purely top-down manner with attentional demands.
|Title:||Studying the Role of Human Parietal Cortex in Visuospatial Attention with Concurrent TMS-fMRI|
|Keywords:||concurrent TMS-fMRI, posterior parietal cortex, state-dependence, visuospatial attention, TRANSCRANIAL MAGNETIC STIMULATION, HUMAN MOTOR CORTEX, HUMAN EXTRASTRIATE CORTEX, HUMAN VISUAL-CORTEX, SPATIAL ATTENTION, SELECTIVE ATTENTION, NEURONAL SYNCHRONIZATION, CORTICAL MECHANISMS, DIRECTED ATTENTION, UNILATERAL NEGLECT|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Psychology and Language Sciences (Division of) > Institute of Cognitive Neuroscience
UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Neurology > Motor Neuroscience and Movement Disorders
UCL > School of Life and Medical Sciences > Faculty of Life Sciences
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