Brain nueromarker may help understand autism and schizophrenia

Researchers from Florida Atlantic University (FAU) have been able to identify neural signatures of effective, real-time coordination between two interacting humans.

Researchers used a specially designed dual-electroencephalogram (EEG) and the concepts of coordination dynamics in the study "The Phi Complex as a Neuromarker of Human Social Coordination," published in the May 8 2007 Proceedings of the National Academy of Sciences.

"While many interactions between people rely on mutual information exchange, little is known about how such social processes are integrated in the brain," said Scott Kelso, the founder of the Centre for Complex Systems and Brain Science of at FAU.

What this research suggests is that a unique pattern can be seen in the brains of two people interacting and that these brain activities distinguish independence from cooperation. This new brain rhythm that we have discovered and termed the "phi complex' actually distinguishes when you're socially interacting and when you're not.

Phi is one of a number of brain rhythms that exist in the awake human brain and appears to have a social function. Rhythms or oscillations are the signature of the underlying cortical networks and are characterised by their frequency, strength and location. Phi operates in the 10 Hz band (10 oscillations per second) and is located above the right centro-parietal cortex. It consists of two components: one favours independent behaviour and the other favours interpersonal coordination between people.

"The phi complex is closely tied to the success of the mutual interaction between people and is not merely a consequence of one person imitating the other," said Dr Emanuelle Tognoli, one of the researchers in the study.

"Our measure of behaviour, the phase or timing relationship between the actions of two people, is important because it characterises the informational exchange between their brains."

The phi complex may prove to be a sensitive probe or neuromarker of neuropsychiatric disorders such as autism and schizophrenia. The research could also identify the neural mechanisms of real-time social behaviour between humans such as leader-follower, male-female and enemy-friend relationships.

"An ever increasing number of mathematicians, physicists and computer scientists in collaboration with neuroscientists are trying to understand how patterns are generated in the human brain and their relation to behaviours," said Dr Gary Perry, dean of the Charles E Schmidt College of Science. "This cross-disciplinary interaction at the cutting edge of science has proven very fruitful, and Dr Kelso and his team are pioneers in this area."