Although consciousness is a multifaceted phenomena, important aspects like awareness and alertness have only been theoretically rather than neurobiologically defined. According to a novel theory, different neurofunctional dimensions of the brain contain aspects of consciousness that may be detected and measured by variations in blood flow across time.
“Consciousness is complex and studying it is like solving a scrambled Rubik’s cube,” [..] “If you look at just a single surface, you may be confused by the way it is organized. You need to work on the puzzle looking at all dimensions.”Zirui Huang, Ph.D., research assistant professor in the University of Michigan Medical School Department of Anesthesiology.
Some examples of these dimensions when it comes to consciousness include arousability, or the brain’s capacity to be awake, awareness, or what we actually experience—such as the color of a rose—and sensory organization, or how sights, sounds, and feelings come to be woven together to create our seamless conscious experience.
The researchers looked for such dimensions of the mind in the brain’s geometry. They looked at the topology or gradients across brain areas rather than at discrete brain regions. The scientists used fMRI data from study participants who were awake, anesthetized, in a sort of coma, or who had mental illnesses like schizophrenia to construct a map of these so-called cortical gradients of awareness.
“What used to be mapped only as a helpful diagram of conscious states might now be mapped in the brain itself.”Anthony G. Hudetz
After that, the team was able to compare how recordings from 400 distinct brain areas altered in response to various states or diagnoses. They discovered three cortical gradients, including those for arousability, awareness, and sensory organization, that appeared to correspond to the aspects of consciousness.
“Our study opens a new view of the link between consciousness and the brain.”Zirui Huang
Functional geometry of the cortex encodes dimensions of consciousness, Zirui Huang, George A. Mashour & Anthony G. Hudetz
Published: January 2023