Investigating ongoing brain oscillations and their influence on conscious perception – network states and the window to consciousness
One of the main goals in cognitive neuroscience is to understand prerequisites of consciousness, which can be studies using near threshold (NT) designs. The main advantage of NT designs is that, while stimulus characteristics remain the same, subjective experience differs. Previous research showed that activity prior to NT stimulus presentation, mainly in the alpha band (8-14 Hz), can predict whether the stimulus is perceived or not. I will present results of a series of MEG studies in different sensory modalities (visual, auditory, somatosensory), which extend these findings and show that not only local excitability changes - as indexed by modulations in specific frequency bands - but, more importantly, also functional network properties play a crucial role. Apparently, sensory areas show a stronger integration into distributed functional networks before the detection of an upcoming NT stimulus. Our findings strongly argue for a “window” to conscious perception, which is characterized by pre-established pathways within relevant networks.