Perceived causality influences brain activity evoked by biological motion

Area of Science:

• Neuroscience
• Cognitive Psychology
• Perception

Background:

• The perception of biological motion is crucial for social interaction.
• Understanding how the brain differentiates between self-initiated and externally caused actions is key to social cognition.

Purpose of the Study:

• To investigate brain activity using fMRI while observers watched hand and arm motions.
• To determine how the brain perceives causality in biological motion.
• To explore hemispheric differences in processing motion intention.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants observed a 3D animated character performing intended and unintended hand/arm motions.
• Control trials involved observing a non-biological motion (coffee mug).

Main Results:

• Both intended and unintended biological motions activated bilateral regions extending from the posterior superior temporal sulcus (pSTS).
• The right hemisphere showed more extensive activation in these pSTS regions.
• The left pSTS differentiated between intended and unintended motion, with higher activity for intended actions.

Conclusions:

• The posterior superior temporal sulcus (pSTS) plays a significant role in perceiving the causality of biological motion.
• A strong hemispheric bias exists, with the left pSTS being crucial for distinguishing action intention.
• These findings advance our understanding of social perception and intention attribution.