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Figure 1. BOLD responses to visual and tactile stimulation (А-C, single subject; D-E1 group data). A,
Lateral view of the partially inflated left hemisphere. Brain areas responsive to visual motion that
showed a response to ipsilateral stimulation (MST; blue) or no response to ipsilateral stimulation
(MT; green) are shown. Dashed white line shows the fundus of the ascending limb of the posterior
inferior temporal sulcus. B, Brain areas in the same subject responding to Vibrotactile stimulation
(orange-to-yellow color scale). C, Composite map showing MST (blue outline) and MT (green
outline) overlaid on tactile activation map (enlarged view of black outlined region in A and S). D,
Random-effects group average map (n=8 subjects) showing location of MST and MT relative to
tactile activation in left hemisphere (anterior is left). E, Group average composite map for right
hemisphere (anterior is right).
To more closely examine MST tactile responses, we calculated the average
evoked response from all MST voxels that showed significant tactile responses (Fig. 2A).
The temporal profile of the evoked response followed the classical BOLD hemodynamic
response function, with a sharp peak 4 s after stimulus onset (2 s after stimulus offset)
followed by a return to baseline within 4 s. There was a strong dependence on the
location Ofstimulation. The largest response was to stimulation of the contralateral
hand (mean of first and second time points, 0.16%) with smaller but still significant
responses to stimulation of the ipsilateral hand and both feet (0.10,0.11, and 0.09%,
respectively). To measure the significance of these differences, we performed an
ANOVA across subjects using two factors, body part Ofstimulation (hand vs. foot) and