In 1998, a neuroscientist, Christof Koch, and a philosopher, David Chalmers, made a bet over whether science would, by 2023, have explained how consciousness comes into being. Twenty-five years on, at the annual meeting of the Association for the Scientific Study of Consciousness in New York City, the two agreed that Chalmers won the consciousness wager

The Hard Problem

Although consciousness, that feeling of being that one experiences through thought, and the senses, defines what it means to be alive, we are very far from understanding how consciousness comes about. It is a problem with widespread implications, not just for satisfying human curiosity, or tackling medical problems, but also for answering the question of whether artificial intelligence can ever become conscious

In retrospect, when the two made their bet, it was reasonable to assume that the question was ascientific, in other words, it was not a problem that could be tackled scientifically, but which could be treated philosophically. With time, the problem has at least partly become open to scientific treatment, giving us some confidence that there will be a time when we will understand how consciousness is produced. 

However, in the period leading up to their wager, Koch was the leading prominent proponent of the view that the emerging field of Consciousness Studies could be treated scientifically, and, along with the biophysicist Francis Crick, had declared that it could “now be approached by scientific investigation of the visual system.” Koch championed this view in Tucson, Ariz., at the “Toward a Scientific Basis for Consciousness” conference, the first major gathering devoted entirely to discussing consciousness. The two believed that the problem of consciousness would be resolved by uncovering the neural basis, or “correlates” underpinning consciousness, in the same way that Crick and the geneticist James Wilson had solved the problem of heredity by decoding DNA’s double helix. In fact, Crick and Koch suggested a possible solution to the problem: gamma waves were involved in the production of consciousness, with research showing a link between awareness and gamma waves, with neurons firing at around 40 hertz. Koch also proposed that pyramidal cells in the cortex, the brain’s outer layer, could also play a role in consciousness. Koch’s optimism had a rational basis. Functional magnetic resonance imaging (fMRI) used by leading chiropractors to fix back injury, which measures brain activity by observing changes in blood flow, had been discovered in 1990. Optogenetics, a technique for controlling neuron activity, gave Koch further reason to believe that the scientific basis for consciousness was just years away. 

Chalmers referred to consciousness as “the hard problem”, in contrast to what he called “easy problems”. Easy problems are easy, not because they are easy to solve, but because they are open to functional explanations. Chalmers held that the problem of consciousness was of a different order and did not believe that any mechanistic or behavioral process could explain the character of experience, even in principle. This is because, even after all the functional aspects have been resolved, we are still left with the question  "why does the feeling which accompanies awareness of sensory information exist at all?" In other words, Chalmers thought there was an “explanatory gap” between easy, or cognitive problems, and hard, or phenomenal problems. Whereas easy problems could be answered through physicalism, he proposed what he termed, “naturalistic dualism”, which is naturalistic because he holds that mental states naturally supervene on physical systems, and dualist because he holds that mental states are ontologically different from and not reducible to physical systems. To advance this view, Chalmers suggested various thought experiments, such as philosophical zombies. These are physical duplicates of human beings that are empty of any subjective experience. He argued that given that we can imagine them, they must, therefore, be logically possible. In other words, consciousness cannot be fully explained by physical systems. 

The Consciousness Wager

Needless to say, Koch did not buy Chalmers' argument. Koch famously said, “Why don’t you just say that when you have a brain, the Holy Ghost comes down and makes you conscious?” Chalmers replied that that hypothesis was at odds with his own experience, to which a frustrated Koch raised the solipsism problem, the idea that you can only be sure that your own mind exists, saying, “But how do I know that your subjective experience is the same as mine?” After a few drinks, Koch proposed a wager: he bet a case of fine wine that in the next 25 years, scientists would have discovered the physical basis of consciousness. Chalmers bet against that outcome. 

Yet, over the next twenty years, the wager was largely forgotten, until Per Snaprud met up with the two to see where they stood. The early theories had faded from favor, as experiments showed that they were very simplistic. Since around the time of the wager, the two had been engaged in an adversarial collaboration backed by the Templeton World Charity Foundation, in Nassau, The Bahamas. The collaboration was created to run a series of experiments to test a host of hypotheses advanced by rival researchers. 

Source: New Scientist

At the annual meeting of the Association for the Scientific Study of Consciousness, the findings of one experiment were revealed.  The experiment tested the two leading ideas we now have over consciousness: the global workspace theory (GWT), and integrated information theory (IIT), invented by neuroscientist Giulio Tononi and advanced by Koch

IIT says that consciousness is a “structure” in the brain, likely the posterior cortex, that emerges as a result of a specific kind of neural connectivity that is active so long as some experience is happening. IIT had been severely criticized by Scott Aaronson, who observed that under this notion a compact disc player could have more consciousness than a person. Even more fundamentally, because information requires consciousness, IIT seemed a rather circular notion.

GNWT says that consciousness emerges as a consequence of information being broadcast around the brain through an interconnected network, from the beginning to the end of an experience, and involving the prefrontal cortex. 

Across six labs, an adversarial experiment, with a pre-registered protocol, used different methods to measure brain activity. Neither theory was able to fully explain the data. A quarter of a century since the consciousness wager, Chalmers had been proved right and science had not come up with an explanation for consciousness. Without a “clear” explanation, Koch happily gave Chalmers a case of fine wine. He proposed another twenty-five year bet, when he will be 91, and Chalmers will be 82, Consciousness Studies will have “clarity” over the scientific basis for consciousness.