Specific involvement of human parietal systems and the amygdala in the perception of biological motion

Abstract

To explore the extent to which functional systems within the human posterior parietal cortex and the superior temporal sulcus are involved in the perception of action, we measured cerebral metabolic activity in human subjects by positron emission tomography during the perception of simulations of biological motion with point-light displays. The experimental design involved comparisons of activity during the perception of goal-directed hand action, whole body motion, object motion, and random motion. The results demonstrated that the perception of scripts of goal-directed hand action implicates the cortex in the intraparietal sulcus and the caudal part of the superior temporal sulcus, both in the left hemisphere. By contrast, the rostrocaudal part of the right superior temporal sulcus and adjacent temporal cortex, and limbic structures such as the amygdala, are involved in the perception of signs conveyed by expressive body movements.

Fig. 1.

Merged PET–MRI sections at x = −48 (sagittal section) and y = −61 (coronal section) to illustrate the activity within the upper bank of the left caudal superior temporal sulcus, in the hand action minus random motion condition. Note that the activity extends into the posterior temporo-occipital region. sts, Superior temporal sulcus. In the coronal section, the subject’s left is on the left side.

Fig. 2.

Coronal merged PET–MRI section at y = −60 to illustrate activity in the lower bank of the right rostrocaudal superior temporal sulcus and adjacent temporal cortex in the body movement minus random motion condition.

Fig. 3.

Coronal merged PET–MRI section at y = −1 to illustrate activity within the amygdala in the body movement minus random motion condition. Note that the activity is more intense on the right side.

Fig. 4.

Coronal merged PET–MRI section at y = −67 to illustrate activity within the caudal superior parietal cortex in the hand action minus body movement condition. Note that the activity lies medial to the intraparietal sulcus.

Fig. 5.

Coronal merged PET–MRI section at y = −44 to illustrate activity within the left intraparietal sulcus in the hand action minus body movement condition. Note that the activity in the right hemisphere is located in the inferior parietal lobule.ips, Intraparietal sulcus.