Evoked Correlates of Consciousness

This project investigates the evoked brain correlates of consciousness. We use Electrocorticography recordings from patients acquired during the period of waking up from deep anaesthesia to awake state. During this period a sequence of 3 blocks of no stimulation, auditory stimulation and somatosensory stimulation respectively is applied repetitively to the patients. This offers the opportunity to study the dynamics of cortical function after evoked sensory activation at different levels of consciousness.

This follows the “zap and zip” approach (Massimini et al 2005 Science) in which evoked stimulation is used to probe the complexity of brain activity at different states of consciousness. The main difference with the “zap and zip” approach is that the evoked stimulation is through sensory stimulation and not through extracranial magnetic stimulation.

The assessment of the post-stimulation brain dynamics at different levels of concoiussness will be based on a battery of different methods falling in 3 different categories:

Assessment of the evoked response potentials and the frequency spectra at different brain locations.
Assessment of complexity and entropy measures at different brain locations,
Assessment of functional and effective connectivity between different brain locations.