Gambling on consciousness
Gambling may provide a new window onto consciousness, according to a paper in the February issue of Nature Neuroscience. Assessing whether someone is aware of something is a notoriously difficult problem that is fundamental to investigating the basis of consciousness. This paper offers a new solution to this classic experimental dilemma by showing that people place bets only when they are aware of what they are betting on.Alan Cowey and colleagues asked participants to do several tasks in which performance is believed to occur without awareness for some of the time. For instance, when asked to classify letter strings into groups according to whether they obey a grammatical rule, participants who have seen examples of the rule in practice can perform at high levels while being unable to explain the rule. Similarly, patients with damage to the visual cortex can often make rudimentary visual judgments about stimuli that they deny seeing.Cowey and colleagues asked people to place a bet on whether or not their response was correct when they completed a trial of each of these tasks. They found that betting and task performance do not go hand in hand. Rather, participants place high bets on trials only when they are aware of the basis of their judgment – for example, when they recognize the rule governing their choices, or they consciously perceive the stimuli they are localizing. This method of measuring awareness is a significant advance over previous techniques because bets are placed without introspection about awareness, which can change what people consciously know.Author contact:Navindra Persaud (University of Oxford, UK)Tel: +44 7767 054 820; E-mail: navindra.persaud@univ.ox.ac.uk