Effects of TMS over Premotor and Superior Temporal Cortices on Biological Motion Perception

摘要

Using MRI-guided off-line TMS, we targeted two areas implicatednin biological motion processing: ventral premotor cortexn(PMC) and posterior STS (pSTS), plus a control site (vertex).nParticipants performed a detection task on noise-maskednpoint-light displays of human animations and scrambled versionsnof the same stimuli. Perceptual thresholds were determinednindividually. Performance was measured before andnafter 20 sec of continuous theta burst stimulation of PMC, pSTS,nand control (each tested on different days). A matched nonbiologicalnobject motion task (detecting point-light displays ofntranslating polygons) served as a further control. Data werenanalyzed within the signal detection framework. Sensitivityn(d0) significantly decreased after TMS of PMC. There was anmarginally significant decline in d0 after TMS of pSTS but notnof control site. Criterion (response bias) was also significantlynaffected by TMS over PMC. Specifically, subjects made significantlynmore false alarms post-TMS of PMC. These effects werenspecific to biological motion and not found for the nonbiologicalncontrol task. To summarize, we report that TMS over PMCnreduces sensitivity to biological motion perception. Furthermore,npSTS and PMC may have distinct roles in biological motionnprocessing as behavioral performance differs followingnTMS in each area. Only TMS over PMC led to a significantnincrease in false alarms, which was not found for other brainnareas or for the control task. TMS of PMC may have interferednwith refining judgments about biological motion perception,npossibly because access to the perceiverʼs own motor representationsnwas compromised