Automatic prediction error responses to hands with unexpected laterality: an electrophysiological study.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Visual Perception

Background:

• The human brain's mechanism for tracking body parts in the visual field remains largely unknown.
• Understanding how the brain processes visual information about body parts is crucial for cognitive neuroscience.

Purpose of the Study:

• To investigate how the brain monitors the laterality (left/right) of hands in the visual field.
• To explore neural correlates of processing unexpected hand images and their relation to handedness.

Main Methods:

• A visual oddball experiment was conducted presenting unattended images of hands.
• Mismatch responses were recorded to hands with unexpected laterality in the visual periphery.
• Brain activity was analyzed using neuroimaging techniques, and correlations with handedness scores were examined.

Main Results:

• Unexpected hand laterality elicited mismatch responses, particularly in the periphery.
• Unexpected left hands were processed mainly in the contralateral superior parietal cortex.
• Unexpected right hands showed more widespread activation in parietal, premotor, prefrontal, and temporal areas, suggesting more elaborate processing of the dominant hand.

Conclusions:

• The brain continuously monitors the left or right identity of hands presented visually.
• This monitoring is essential for transforming observed actions into an observer's egocentric spatial reference frame.
• Differential processing of dominant hands suggests specialized neural mechanisms for self-representation.