The Role of Top-Down Modulation in Shaping Sensory Processing Across Brain States: Implications for Consciousness.
Frontiers in systems neuroscience January 1, 2019 Tom Sikkens, Conrado A Bosman, Umberto Olcese 48 citations
Feedback connections, which make up a large portion of neural links in the thalamocortical system, are thought to be essential for conscious perception, according to major theories of consciousness. These theories predict that feedback modulation should be reduced in nonconscious brain states such as non-REM sleep and anesthesia, and when sensory stimuli are not perceived. However, recent experiments on mismatch negativity, a phenomenon linked to top-down modulation, show that feedback modulation persists during nonconscious states, though it is generally dampened. These deviations challenge current theories and may require reevaluating how consciousness is assessed in supposedly nonconscious states.