Network activity underlying the illusory self-attribution of a dummy arm.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Illusory self-attribution of body parts involves frontal and intraparietal areas.
• Visual body-selective regions in the occipitotemporal cortex are also implicated.
• Understanding information flow within this network is crucial.

Purpose of the Study:

• Investigate the neural network and information exchange during illusory self-attribution of a body part.
• Clarify the role of visual and somatosensory integration in body ownership illusions.

Main Methods:

• Used fMRI with automated congruent/incongruent visuotactile stimulation of a participant's arm and a dummy arm.
• Induced illusory self-attribution of a dummy arm.
• Analyzed functional coupling and effective connectivity using dynamic causal modeling.

Main Results:

• Illusion activated a left-hemispheric network: ventral premotor cortex (PMv), intraparietal sulcus (IPS), and lateral occipitotemporal cortex (LOC).
• Increased functional coupling between PMv, IPS, and LOC during the illusion.
• Enhanced connections from LOC and secondary somatosensory cortex to IPS.

Conclusions:

• Results support a hierarchical propagation of prediction error model for brain inference.
• Unpredicted sensory input during illusions may generate prediction errors.
• These errors are conveyed to parietal areas for integration.