An international team of experts led by physicists at Monash has come up with a new technique to measure consciousness, which would likely change our understanding of neurological matters. The paper detailing the findings has been published in the journal Physical Review Research and explains the way tools from physics and complexity hypothesis were employed to assess the level of consciousness in fruit flies.
“This is a major problem in neuroscience, where it is crucial to differentiate between unresponsive vegetative patients and those suffering from a condition in which a patient is aware but cannot move or communicate verbally because of complete paralysis of nearly all voluntary muscles in the body,” said study author Dr. Kavan Modi, from the Monash University School of Physics and Astronomy.
The Relation Between Consciousness and Complexity
The team of scientists, which includes Dr. Modi, Ph.D. candidate Roberto Muñoz from the School of Physics and Astronomy, and Monash University Psychology Associate Professor Nao Tsuchiya, has discovered a way to determine the level of conscious arousal in fruit flies employing the complex signals generated by the brain.
“Our technique allows us to distinguish between flies that have been anesthetized and those that have not, by calculating the time-complexity of the signals,” said Dr. Modi. “The study is significant because it highlights an objective way to measure conscious arousal, based on well-established ideas from complexity theory. It is potentially applicable to humans — and it reflects a growing interest in new theories of consciousness that are experimentally testable.”
The research team analyzed the brain signals produced by 13 fruit flies when they were awake and also when under anesthesia. They then examined the signals to see how intricate they are.
“We found the statistical complexity to be larger when a fly is awake than when the same fly is anesthetized,” Dr. Modi explained. “This is important because it suggests a reliable way to determine the level of conscious arousal by tapping into a small region of the brain, rather than many parts of the brain. It also suggests that there is a clear marker of conscious arousal that does not depend on specific external stimuli.”
The study determined that applying a similar analysis to other datasets, especially human EEG data could lead to new findings on the correlation between consciousness and complexity. The research is titled “General anesthesia reduces complexity and temporal asymmetry of the informational structures derived from neural recordings in Drosophila” and has been published in Physical Review Research.