PRIMATES AND MICE

Testing Global Neuronal Workspace and Integrated Information Theories in Animal Models

Understanding consciousness comes with the need to uncover what kinds of brain activity correspond exactly with conscious experiences. These specific forms of activity are known as neural correlates of consciousness (NCCs). Two major theories of consciousness, Global Neuronal Workspace (GNW) and Integrated Information Theory (IIT), propose fundamentally different NCCs. This adversarial collaboration, replicated across multiple laboratories, tests the predictions of GNW and IIT. It is the third in a series of Structured Adversarial Collaborations, involving the laboratories of Maria Geffen (University of Pennsylvania), Shawn Olsen (Allen Institute), Theofanis Panagiotaropoulos (Neurospin) and Yuri Saalmann (University of Wisconsin, Madison).
The team will use high-density Neuropixel probes to record activity from individual neurons across the anterior-posterior extent of the cerebral cortex in non-human primates (NHPs) and mice. In addition, they will employ electrical stimulation (in NHPs) and optogenetics (in mice) to causally manipulate brain networks. This will put key and opposing predictions of each theory to the test.
During behavioural experiments, NHPs and mice will view or listen to stimuli of varying durations and be trained to respond when a stimulus is detected (a “go / no-go” task). To manipulate awareness, a backward masking technique will also be used. Here, a stimulus is quickly followed by another one, interrupting its processing.

To test specific predictions of GNW and IIT, the team will then analyse the neural data by decoding responses across different stimulus conditions and measuring interactions between neurons. This will allow to distinguish the neural representations that are truly related to conscious experience from those only related to the action of reporting a stimulus.
The project will provide the first-of-its-kind high spatiotemporal resolution tests and causal evidence for or against each of these two important theories of consciousness. It will also shed light on whether these mechanisms are shared across species, providing insight into the evolution of the NCCs.
The project is expected to produce several high-impact research publications for the field, as well as a large open-access dataset and useful analytical tools. The outcomes of the project will be evidence supporting or challenging two major theories of consciousness, significantly advancing our understanding of this puzzling phenomenon.