Dual EEG study discovers new brain rhythm during social interaction
22 May 2007 The discovery of a new brain neuromarker may prove to be a
sensitive probe of neuropsychiatric disorders such as autism and
schizophrenia where the inability to have harmonious social interactions is
problematic. This research also opens up untapped possibilities to identify
the neural mechanisms of real-time social behaviour between humans.
Researchers from Florida Atlantic University (FAU) have been able to
identify neural signatures of effective, real-time coordination between
people in one of the first studies in the field of social neuroscience to
actually record, measure and analyze both behaviour and brain activity
simultaneously in two interacting humans. Researchers used a specially
designed dual-electroencephalogram (EEG) and the conceptual framework and
methods of coordination dynamics in this study, “The Phi Complex as a
Neuromarker of Human Social Coordination,” published in the May 8, 2007
Proceedings of the National Academy of Sciences. The research was conducted
by Drs. Emmanuelle Tognoli, Julien Lagarde, Gonzalo DeGuzman and J.A. Scott
Kelso in The Human Brain and Behavior Laboratory at the Center for Complex
Systems and Brain Sciences in the Charles E. Schmidt College of Science at
FAU.
 |
Dual-EEG
recording, measuring and analyzing both behaviour and brain activity
simultaneously in two interacting humans. |
Using EEG recordings, Tognoli and colleagues collected the brain activity
of two people simultaneously performing continuous finger motion. At first,
the two subjects were asked to wag their fingers but were not allowed to see
each others’ hands. Then, like the shutter release of a camera, the barrier
placed between them was removed so they could see each other as they
continued to wag their fingers. When subjects were allowed to see each
others’ fingers moving, sometimes they adjusted their own movements and
synchronized with each other, and sometimes they did not, behaving
independently. “While many interactions between people rely on mutual
information exchange, little is known about how such social processes are
integrated in the brain,” said Kelso, the Glenwood and Martha Creech Eminent
Scholar in Science and founder of the Center for Complex Systems and Brain
Sciences. “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 natural language of the
brain. They are the signature of the underlying cortical networks and are
characterized 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 favors
independent behaviour and the other favors 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 Tognoli. “Our measure of behavior, the
phase or timing relationship between the actions of two people, is important
because it characterizes the informational exchange between their brains.”
The success or failure of this information exchange revealed in this new
brain rhythm will serve as a stimulus for the scientific community to
further investigate the phi complex and its implications for understanding
not only normal social cognition, but pathologies of social behaviour.
“The ground-breaking research by Dr. Scott Kelso and colleagues leading to
the discovery of this new brain rhythm related to human social interactions
opens up the potential to now understand how and why we as humans relate to
each other the way we do,” said Dr. Larry F. Lemanski, vice president for
research at FAU. “Moreover, this exciting new finding may lead to a better
understanding of and better diagnostic protocols for various
neuropsychiatric disorders.” The phi complex may prove to be a sensitive
probe or neuromarker of neuropsychiatric disorders such as autism and
schizophrenia where the inability to have harmonious social interactions is
problematic. In addition, this research opens up many new and untapped
possibilities to identify the neural mechanisms of real-time social behavior
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 behavior,” 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.” This research has emerged as a result of continuous research
support from the National Institutes of Mental Health (NIMH) over the course
of more than 20 years for a project entitled, “Dynamic Patterns in Complex
Biological Systems,” awarded to Kelso. This project was further enhanced by
the Director’s “Innovations” award, also from the NIMH awarded to Kelso and
his team. The U.S. Office of Naval Research contributed funding in the later
stages of the project and continues to support their ongoing research.
Post this page to Del.icio.us To top
|