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scrambled static images in STSms. However, some neurons in TPO are face-selective
(Baylis, et al. 1987; Bruce, et al. 1981) and human fMRI studies have described face
selectivity in the posterior STS (Kanwisher, et al. 1997).
In addition to similar visual processing profiles, the response selectivity of STSms
to auditory and tactile stimuli was similar to that of macaque STP. Auditory-responsive
STP neurons show broad-spectrum responses, with similar activity to very different
sounds, such as pure tones, voices, white noise, and hand clapping (Bruce, et al. 1981;
Hikosaka, et al. 1988). Consistent with this result, we saw robust activity in STSms to our
auditory stimuli, which were pure tones in Experiment 1 and a variety of animal, human
and mechanical sounds in Experiment 2. In tactile STP neurons, strong responses are
evoked by cutaneous stimuli (Bruce, et al. 1981; Hikosaka, et al. 1988). The spatial
preference of these neurons varies widely, from neurons that represent the entire body
surface, to neurons that represent the contralateral body surface, to neurons that
represent only the contralateral hand and arm. Estimating the ensemble response of
these neurons, we would predict the largest responses to contralateral hand stimulation
(which would activate all neurons) with the smallest responses to ipsilateral stimulation
(which would activate only whole-body neurons). Consistent with this analysis, we
observed the greatest BOLD activation in STSms for contralateral hand stimulation, and
significantly weaker BOLD activation for ipsilateral hand and contralateral foot
stimulation.