Somatotopy of the human arm using fMRI.
We describe a technique for mapping out human somatosensory cortex using functional magnetic resonance imaging (fMRI). To produce cortical activation, a pneumatic apparatus presented subjects with a periodic series of air puffs in which a sliding window of five locations moved along the ventral surface of the left arm in a proximal-to-distal or distal-to-proximal direction. This approach, in which the phase-delay of the stimulus can be used to produce somatotopic maps of somatosensory cortex, is based on a method used to generate retinotopic maps of visual cortex. Functional images were acquired using an echoplanar 1.5T scanner and a T2*-weighted spiral acquisition pulse sequence. The periodic series of air puffs created phase-related activation in two cortical regions of the contralateral parietal lobe, the posterior bank of the central sulcus and a more posterior and lateral region.
Servos
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Department of Psychology, Stanford University, CA 94305, USA.
Zacks
J
J
Rumelhart
D E
DE
Glover
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GH
D000328:Adult; D000388:Air; D001132:Arm / Q000294:innervation*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010812:Physical Stimulation; D013003:Somatosensory Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D016683:Supine Position