Alpha brain waves shape how we recognize our own body

A Karolinska Institute study found that the speed of alpha-frequency oscillations in the parietal cortex correlates with the brain's temporal binding window and with reported body ownership, based on EEG and rubber-hand experiments with 106 participants published in Nature Communications.

Researchers at the Karolinska Institute report that a basic brain rhythm helps determine how people perceive their own bodies. The team studied alpha-frequency oscillations in the parietal cortex. They tested 106 volunteers using EEG and a rubber hand illusion task. Results were published in Nature Communications. Key findings: - Faster alpha oscillations in the parietal cortex correlated with a shorter temporal binding window, meaning greater sensitivity to timing differences between touch and sight. - The temporal binding window (TBW) is the period when the brain treats visual and tactile signals as if they occur together despite small timing differences. - In the rubber hand illusion tests, synchronous touch tended to increase reported ownership of the artificial hand, while asynchronous touch reduced that feeling; individual differences aligned with alpha speed. - Researchers used a non-invasive approach to alter alpha speed and observed corresponding changes in the precision of reported body ownership. - The authors reported that the mechanism might be relevant to psychiatric conditions such as schizophrenia and to the sensory experience of people using artificial limbs. Summary: The study links the speed of alpha-frequency brain oscillations to how long the brain groups touch and vision into a single event and to measures of body ownership. The authors noted that further research could examine whether this process is involved in psychiatric conditions and in improving sensory outcomes for prosthetics. Undetermined at this time.