Global Workspace Theory

Global Workspace Theory (GWT) proposes that consciousness arises when information is broadcast widely throughout the brain via a "global workspace." Originally developed by Bernard Baars in the 1980s and later given a neural implementation by Stanislas Dehaene and colleagues, the theory draws an analogy between consciousness and a theater stage where a spotlight illuminates certain content, making it available to a wide audience of specialized processors.

The core mechanism involves competition among unconscious specialized brain modules for access to a limited-capacity global workspace. When information wins this competition and enters the workspace, it is broadcast to many brain regions simultaneously, enabling flexible, coordinated responses. This global availability is what constitutes conscious experience according to GWT. The neural implementation, sometimes called Global Neuronal Workspace Theory, identifies the prefrontal and parietal cortices as key nodes that enable widespread broadcasting through long-range neural connections.

GWT explains several features of consciousness, including its limited capacity (the workspace can only hold one coherent content at a time), the unity of conscious experience (broadcast information is globally available), and the distinction between conscious and unconscious processing (only broadcast information becomes conscious). The theory has been influential in experimental consciousness science because it makes testable predictions about the neural signatures of conscious perception, including "ignition" events where neural activity suddenly becomes widespread and sustained.