Prestimulus Network Integration of Auditory Cortex Predisposes Near-Threshold Perception Independently of Local Excitability.
Cerebral cortex (New York, N.Y. : 1991) December 1, 2015 Sabine Leske, Philipp Ruhnau, Julia Frey et al.
Brain regions crucial for hearing a faint sound are already coupled before the sound arrives, forming pre-established pathways that influence whether the sound is consciously perceived. Using magnetoencephalography and graph theory, the study found that in a near-threshold auditory task, the left auditory cortex behaved like a hub and was more integrated into the brain's functional network prior to conscious perception, while right auditory regions were decoupled from non-auditory areas. Local excitability, measured by decreased alpha power in the auditory cortex, also increased before conscious percepts. These connectivity and excitability states were largely independent of each other.