In a mood-lit University of Quebec auditorium with red velvet seating, hundreds of researchers gather for the 2012 Summer Institute in Cognitive Science. Some of the field's biggest names are in attendance -- there's emininent philosopher John Searle, to whom we owe the "Chinese room" thought experiment; rabble-rouser Dan Dennett, who argues with panache that self-awareness is an illusion; Stevan Harnad, the theorist who reshaped robotics in his youth by defining the (still unsolved) "symbol grounding" problem"; and Simon Baron-Cohen, psychopathologist and top expert on autism.
While the world celebrates the discovery of the Higgs boson, these scientists are hard at work on one of the most profound mysteries left: Why, and how, did humans became conscious?
Many of the experts in attendance, like David Rosenthal, believe that consciousness is the exhaust of the brain, which arises from the neurological processes that actually control our actions. While being conscious may enrich our lives, it has as much influence on our behaviour as a paintjob does on the inner workings of a car. This is often called the "Steamwhistle Hypothesis", for early proponent Thomas Huxley, who compared consciousness to the steamwhistle on a locomotive -- it clues us in to what the train is doing, but it has no power to change it.
Many of the things our brains do consciously don't seem to require consciousness at all. For example, the brain is very good counting small groups of objects without our active awareness, what's called subitizing. This is why when most people are presented with five or fewer objects, they immediately know how many there are, without having to count them.
But for anything larger than five, most of us have start counting in our heads or on our fingers to tell how many objects there are. Since we perform the task much faster and more accurately when we do it unconsciously, it's not clear why automated brain processes have evolved to stop counting at five and force the conscious mind to take over.
Similar to subitizing, the majority of what goes on in the brain happens without our awareness. By some estimates, upwards of 90 per cent of the functions the nervous system performs are unconscious, including things like regulating sleep cycles, sorting and editing sensory information and controlling physical movement. Even some things that we believe we do consciously, like identifying objects and people, are actually unconscious. Through many studies, we've learned that patients with brain lesions who aren't consciously aware of an object can still identify it, and those who have no trouble seeing and interacting with objects can be pathologically unable to identify them. Awareness and recognition are two different processes in the brain, neither of which requires the other.
But if consciousness isn't necessary for most of what our brain does, why do we have it at all? Why didn't we evolve to be mindless automatons, like computers, plants, or -- a philosophy favourite -- zombies? Consciousness must have provided some advantage to our survival, otherwise we wouldn't have wasted energy on it -- right?
At the Summer Institute, theories are abound. Roy Baumeister believes that consciousness developed to help us share information and generate knowledge socially; he argues that our brains talk to themselves as a necessary step towards talking to others. Meanwhile Axel Cleeremans argues that consciousness is the brain's "theory about itself," a simulation which helps the biological brain understand what effects its actions have on itself, other people and the environment. Bjorn Merker and Michael Shadlen give consciousness a central role in decision-making; Ezequiel Morsella emphasizes its role in globally sharing information throughout the brain. Gaultiero Piccinini reasons that consciousness could be vestigial, like the male nipple or the whale's pelvic bone. Perhaps consciousness is the unavoidable consequence of the way our brains are structured, which arose by chance and remains because there are no good evolutionary reasons to abandon it.
If it all seems like wild speculation, that's because it is. Consciousness is the untamed frontier of brain science. Despite a growing body of MRI neuroimaging studies and increasingly refined knowledge of where functions are located in the brain, the biological basis for consciousness -- what cognitive scientists call the "neural correlates of consciousness" -- has so far eluded discovery. All that's been established is that there is no one region of the brain devoted to consciousness, the way there are regions dedicated to vision, decision-making or memory processing. It's distributed across many regions and systems, hiding in the cracks somewhere.
Until we can figure out what consciousness physically is, there won't be any consensus on what function it serves, or indeed whether it serves any function at all. My guess is, the jury will be out for a long time on this one.