| Autor: |
Ricci R; Brain Stimulation Laboratory, Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina Charleston, SC, USA ; Department of Psychology and Neuroscience Institute of Turin, University of Turin Turin, Italy., Salatino A, Li X, Funk AP, Logan SL, Mu Q, Johnson KA, Bohning DE, George MS |
| Jazyk: |
angličtina |
| Zdroj: |
Frontiers in human neuroscience [Front Hum Neurosci] 2012 Dec 17; Vol. 6, pp. 326. Date of Electronic Publication: 2012 Dec 17 (Print Publication: 2012). |
| DOI: |
10.3389/fnhum.2012.00326 |
| Abstrakt: |
Applying a precisely timed pulse of transcranial magnetic stimulation (TMS) over the right posterior parietal cortex (PPC) can produce temporary visuo-spatial neglect-like effects. Although the TMS is applied over PPC, it is not clear what other brain regions are involved. We applied TMS within a functional magnetic resonance imaging (fMRI) scanner to investigate brain activity during TMS induction of neglect-like bias in three healthy volunteers, while they performed a line bisection judgment task (i.e., the landmark task). Single-pulse TMS at 115% of motor threshold was applied 150 ms after the visual stimulus onset. Participants completed two different TMS/fMRI sessions while performing this task: one session while single-pulse TMS was intermittently and time-locked applied to the right PPC and a control session with TMS positioned over the vertex. Perceptual rightward bias was observed when TMS was delivered over the right PPC. During neglect-like behavior, the fMRI maps showed decreased neural activity within parieto-frontal areas, which are often lesioned or dysfunctional in patients with left neglect. Vertex TMS induced behavioral effects compatible with leftward response bias and increased BOLD signal in the left caudate (a site which has been linked to response bias). These results are discussed in relation to recent findings on neural networks subserving attention in space. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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