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in and near posterior superior temporal sulcus, middle temporal gyrus, and inferior
temporal sulcus. Because this brain region contains the medial superior temporal area
(MST) and the superior temporal polysensory (STP) areas, we labeled it the MST∕STP
ROI. Two additional ROIs were created from subsets of voxels in SI. The Slfoot ROI was
created from all contiguous voxels on the vertex and medial face of the hemisphere that
showed a significantly greater response to foot than to hand stimulation (p < 0.05). The
Slhand ROI was created from all contiguous voxels near the so-called hand knob
(Yousry, et al. 1997) that showed a significantly greater response to hand than to foot
stimulation (p < 0.05). In order to study the effect of ROI size on classification
performance, permutation testing was used (Haynes and Rees 2005b). For a given ROI
size s, s voxels were randomly selected from the ROI and used to train and test a
classifier. This process was repeated IOO times (with different pools of s randomly
selected voxels) to give the average performance of the ROI at size s. Across subjects,
the performance was averaged at size s and the between-subjects variance was used to
calculate the SD. This process was then repeated across values of s.