Summary: Network nodes that process conscious perception are built on top of the subliminal state, which represents the core of the network. A mathematical model suggests the subliminal state is the most robust part of the consciousness network.
Source: City College New York
Unique in its application of a mathematical model to understand how the brain transitions from consciousness to unconscious behavior, a study at The City College of New York’s Benjamin Levich Institute for Physico-Chemical Hydrodynamics may have just advanced neuroscience appreciably. The findings, surprisingly by physicists, suggest that the subliminal state is the most robust part of the conscious network and appear on the cover of the journal Neuroscience.
“It’s a big step forward in terms of analysis and investigation of the brain,” said City College Ph.D. student Francesca Arese Lucini of the research, entitled “How the Brain Transitions from Conscious to Subliminal Perception,” that she led. “A lot of companies and startups are now focused on understanding more on how (people) work by focusing a lot of energy and money on investigating the brain. This study will probably interest those entrepreneurs or researchers that will focus on artificial intelligence and human-computer interaction devices.”
Arese Lucini and a team of physicists analyzed functional MRI imaging of different subjects in order to obtain the corresponding brain activation. From the brain activation, they obtained functional networks for the conscious state and compared this network to the subliminal state for each fMRI stream.
A reduction of the conscious network, by a k-core decomposition, left the k-core only, the maximal subgraph of nodes of the network with at least k neighbors. The k-core of the conscious state is reduced to three active regions of the brain, the fusiform gyrus (left and right) and the precentral gyrus. These regions are the only active in the subliminal state.
“This implies that the k-core decomposition model could help identify in mathematical term what is the subliminal state of the brain and according to such model, the subliminal state, is identified as the most robust part of the conscious network,” observed Arese Lucini. “We can then postulate that the nodes of the network which are involved in the process of conscious perception are built on top of the subliminal state which represents the core of the network.”
Highlighting the significance of the research, Hernán A. Makse, a professor in CCNY’s Division of Science and a Fellow of the American Physical Society, pointed at its publication in a top neuroscience journal, a rarity for a paper by physicists.
Makse supervised the study whose other contributors were Levich Institute postdoc Gino Del Ferraro, and Mariano Sigman. The latter’s affiliations include the Universidad Torcuato Di Tella (Argentina) and Universidad Nebrija (Spain).
About this neuroscience research article
Source: City College New York Media Contacts: Jay Mwamba – City College New York Image Source: The image is in the public domain.
How the Brain Transitions from Conscious to Subliminal Perception
We study the transition in the functional networks that characterize the human brains’ conscious-state to an unconscious subliminal state of perception by using k-core percolation. We find that the most inner core (i.e., the most connected kernel) of the conscious-state functional network corresponds to areas which remain functionally active when the brain transitions from the conscious-state to the subliminal-state. That is, the inner core of the conscious network coincides with the subliminal-state. Mathematical modeling allows to interpret the conscious to subliminal transition as driven by k-core percolation, through which the conscious state is lost by the inactivation of the peripheral k-shells of the conscious functional network. Thus, the inner core and most robust component of the conscious brain corresponds to the unconscious subliminal state. This finding imposes constraints to theoretical models of consciousness, in that the location of the core of the functional brain network is in the unconscious part of the brain rather than in the conscious state as previously thought.