Talks and Conference Presentations
Cognitive Neuroscience Society
10th Annual Meeting
March 29-April 1, 2003
New York, New York
Neurofunctional Organization of Biological Motion Perception: an fMRI Study of Eye, Hand, and Mouth Movements
K. A. Pelphrey2,1, C. R. Michelich1, R. J. Viola1, P. B. Mack1, T. Allison3, G. McCarthy1
In an early fMRI study, our lab demonstrated that the human superior temporal sulcus (STS) region is activated by observed eye and mouth movements (Puce et al., 1998). We later demonstrated that STS activity is modulated by the perceived intentionality of gaze shifts (Pelphrey et al., 2003). Numerous other studies have confirmed that viewing human movements (e.g., ambulation, hand, eye, mouth movements) preferentially engages the STS (reviewed in Allison et al., 2000). However, the experimental control stimuli used in prior studies of whole body biological motions have typically been point-light displays with elements moving randomly or in a scrambled (non-biological) fashion. Although these studies have established that biological motion activates the posterior STS relative to a subset of possible controls, control stimuli involving complex coherent motion of non-biological entities have not been employed. Thus, it is still not clear the activity in the STS region is elicited by biological motion or by any complex coordinated meaningful motion. In a preliminary study, using fMRI, we first sought to determine whether biological motion preferentially activates the STS region compared to complex, meaningful, and coordinated mechanical motion.
Next, we compared, on a within-subjects basis, activity in the STS elicited by three kinds of biological motion – eyes, mouth, and hand movements. A distribution for the type of biological motion observed in the STS region has not yet been described. Allison et al. (2000, see their Figure 3, p. 269) suggested an anterior-to-posterior (A-P) distribution similar to that observed for the supplementary motor area (SMA; Allison et al., 1996), with hand movements activating posterior and eye and mouth movements activating more anterior regions of the STS. However, inferences about a possible topography remain equivocal because they have been based solely on between-studies comparisons. There may be no STS topography, or the topography may be organized according to a principal other than somatotopy (e.g., by social relevance).