Abstract :
[en] Mind blanking (MB) is a waking state during which we do not report mental content. We recently showed that an fMRI brain pattern of globally positive functional connectivity was the closest to the cerebral configurations when reporting MB1. From a theoretical perspective, this finding can challenge various models of consciousness. For example, the global neuronal workspace theory posits that a stimulus becomes reportable when some of its locally processed information becomes available to a wide range of brain regions, forming a balanced distributed network. A key process of this global broadcasting is ignition, i.e. a sudden, coherent, and exclusive activation of a subset of workspace neurons that code a particular content, while the remainder of the workspace neurons stay inhibited. If the global neuronal workspace ignition is always related to selective neural activation and inhibition (content), the theory cannot account for how MB can still be reported if it is linked to a functional connectome with only positive connections. Similar to the integrated information theory (IIT), in order to generate an experience, a physical system must be able to discriminate between a large repertoire of states (information). This must be done as a single system that cannot be decomposed into a collection of causally independent parts (integration). So far, the IIT can explain the inability to report mental content in brain states with extreme functional integration (i.e., functional hyperconnectivity), as during generalized epilepsy where an abnormally large number of regions work in synchrony, and, as a result, the brain becomes no longer capable of processing information in a way that leads to conscious experience. The here-identified all-to-all positive connectivity pattern shows the highest level of integration and efficiency and the lowest level of segregation and modularity compared to the other brain patterns (16). Therefore, this may imply that such a neural configuration is unable to produce a balance between values of integrated information and segregation of it, leading to limited experience, such as MB. If the role of integration is emphasized over the role of segregation, as in the recent version of IIT, then MB challenges that approach, making a clear case for the importance of segregation of information within neural configurations of conscious content. Importantly, the integration in IIT happens only when there is a content of experience, being reported or not, which is counterintuitive for MB.
