Periodic Reporting for period 3 - CONSCIOUSNESS (Towards a neural and cognitive architecture of consciousness) Reporting period: 2020-05-01 to 2021-10-31 Summary of the context and overall objectives of the project For decades the cognitive neuroscience community has expended significant effort identifying system-level neural correlates of human consciousness, broad neural signatures that distinguish conscious from unconscious processes at the level of whole brain regions. Meanwhile, within the field of neurobiology, rapid progress has been made in understanding the neurotransmitter systems underlying basic sensory processes (e.g. in mice, monkeys). This research has, however, been performed in relative isolation from studies of human consciousness, and clear opportunities to link the two levels of description remain largely unexplored. In this project we will establish this link by combining state-of-the-art neuroimaging techniques with pharmacological interventions. This ERC project consists of three subprojects. In project 1, existing theories of consciousness will be validated and refined by isolating system-level neural correlates of consciousness. In project 2, we are testing the hypothesis that NMDA receptors play a crucial role in “recurrent processing”, the dynamic information exchange between brain regions, thought to give rise to consciousness. We will also test the hypothesis that rapid fluctuations in spontaneous network activity (modulating arousal levels), which are controlled by noradrenaline and acetylcholine neuromodulatory systems, determine the likelihood of sensory evoked recurrent processing, and hence consciousness, to occur. In project 3, we will test the hypothesis that recurrent processing provides the possibility for prolonged and flexible information processing, which could represent a potential function of consciousness.In summary, the proposed research has the potential to gain fundamental insights in the neural mechanisms of human consciousness. In so doing, the work will advance scientific understanding of the long-debated functional significance of consciousness for human cognition and behavior. This fundamental work may potentially benefit the diagnosis, prognosis and treatment of patients with disorders of consciousness in the future. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far This ERC project consists of three subprojects, which have all started (we are half-way the ERC project now). Several individual studies are part of each subproject. Because these three (sub)projects are all very time consuming and complicated to set up and perform and because several novel analysis pipe lines had to be developed, none of the subprojects have finished yet at the moment, although some individual studies are almost finished. We are well underway testing several core hypothesis of these subprojects. For example, we have started the studies in which we test the hypothesis that NMDA receptors play a crucial role in “recurrent processing”, the dynamic information exchange between brain regions, thought to give rise to consciousness. We are also already testing the hypothesis that rapid fluctuations in spontaneous network activity (modulating arousal levels), controlled by noradrenaline and acetylcholine neuromodulatory systems, determine the likelihood of sensory evoked recurrent processing, and hence consciousness, to occur. We anticipate to be able to report results of these ERC projects very soon. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) The proposed research has the potential to gain fundamental insights in the neural processes, at the neurotransmitter level and system-level, of human consciousness. In so doing, the work will advance scientific understanding of the long-debated functional significance of consciousness for human cognition and behavior.
