Attention to touch modulates activity in both primary and secondary somatosensory areas.
We used fMRI to establish whether attention to touch enhances somatosensory cortical activity. Subjects received somatosensory and visual stimulation and were instructed to attend selectively to one modality during alternating stimulus detection periods interspersed with rest periods during which no stimulus was delivered. The maximum signal change for each task versus rest was measured in anatomically defined regions of interest for each subject. Attended touch produced greater signal change than unattended touch in primary (S1) and secondary (S2) somatosensory cortex. In contrast to the conclusions of some previous studies, we found that the enhancement of activation with attention was at least as great in S1 as in S2. The attentional effect was unilateral in S1 and bilateral in S2 and the somatosensory insula.
Johansen-Berg
H
H
Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB), Dept of Clinical Neurology, University of Oxford.
Christensen
V
V
Woolrich
M
M
Matthews
P M
PM
D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D010812:Physical Stimulation; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D013003:Somatosensory Cortex / Q000502:physiology*; D014034:Toes / Q000294:innervation / Q000502:physiology; D014110:Touch / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology