Dehaene and Changeux, 1998

Consciousness Is Global Information Sharing

What kind of information-processing architecture underlies the conscious mind? What is raison d’etre, is functional role in the information-based economy of the brain? My proposal can be stated succinctly. When we say that we are aware of a certain piece of information, what we mean is just this: the information has entered into a specific storage area that makes it available to the rest of the brain. Among the millions of mental representations that constantly crisscross our brains in an unconscious manner, one is selected because of its relevance to our present goals. Consciousness makes it globally available to all our high-level decision systems. We possess a mental router, an evolved architecture for extracting relevant information and dispatching it. The psychologist Bernard Baars calls it “global workspace”: an internal system, detached from the outside world, that allows us to freely entertain our private mental images and to spread them across the mind’s vast array of specialized processors (Figure above)

According to this theory, consciousness is just brain-wide information sharing. Whatever we become conscious of, we can hold it in our mind long after the corresponding stimulation has disappeared from the outside world. That’s because our brain has brought it into the workspace, which maintains it independently of the time and place at which we first perceived it. As a result, we may use it in whatever way we please. In particular, we can dispatch it to our language processors and name it; this is why the capacity to report is a key feature of conscious state. But we can also store it in long-term memory or use it for our future plans, whatever they are. The flexible dissemination of information, I argue, is a characteristic property of the conscious state.

The workspace idea represents a synthesis of many earlier proposals in the psychology of attention and consciousness. As early as 1870, the French philosopher Hippolyte Taine introduced the metaphor of a ‘theater of consciousness.’ The conscious mind, he explained, is like a narrow state that lets us hear only a single actor:

“You may compare the mind of a man to the stage of a theatre, very narrow at the footlights but constantly broadening as it goes back. At the footlights, there is hardly room for more than one actor… As one goes further and further away from footlights, there are other figures less and less distinct as they are more distant from the lights. And beyond these groups, in the wings and altogether in the background, are innumerable obscure shapes that sudden call may bring forward and even within direct range of the footlights. Undefined evolutions constantly take place throughout this seething mass of actors of all kinds, to furnish the chorus leaders who in turn, as in a magic lantern picture, pass before our eyes.”

~ Page 164/165