Role of dorsal and ventral stream development in biological motion perception.

Little is known about the functional development of dorsal and ventral visual streams. The right posterior superior temporal sulcus (pSTS) represents a pivotal point of the two streams and is involved in the perception of biological motion. Here, we compared brain activity between children (aged 5-7 years) and adults (aged 20-32 years) while they were viewing point-light dot animations of biological motion. Biological motion-related activation was found in right pSTS of adults, and in right fusiform gyrus and left middle temporal lobe of children. Group comparisons revealed increased activity in pSTS for adults and in fusiform gyrus for children. Only poorly performing children showed fusiform gyrus activity. These findings indicate that pSTS functioning is not adult-like at the age of 6 years.