25-Year Science Bet on Neural Basis of Consciousness Settled Without Clear Resolution

In 1998, a wager was made between neuroscientist Christof Koch and philosopher David Chalmers regarding one of the greatest enigmas in science: how does the brain produce consciousness? After 25 long years, this bet ended at the Association for the Scientific Study of Consciousness (ASSC) annual meeting in New York City on 23rd June 2023. To a packed audience, the two scientists agreed that the quest is still ongoing, and the answer remains elusive.

The Initial Confrontation

Koch, clad in gold and red, and Chalmers, in black, first butted heads over this matter at the legendary conference, “Toward a Scientific Basis for Consciousness,” in Tucson, Arizona, back in 1994. Besides biophysicist, Francis Crick, Koch argued that understanding consciousness was scientifically attainable, much like the decoding of DNA’s double helix by Crick and James Watson. Their hypothesis centered around the neural underpinnings, or “correlates,” of consciousness, with brain cells firing in synchrony 40 times per second being a potential basis for consciousness. Chalmers met this with skepticism and referred to consciousness as “the hard problem.”

Alternative Theories

  • The Information Hypothesis: Chalmers proposed an alternative hypothesis, suggesting that consciousness might be accounted for by assuming that “information” is a fundamental property of reality. This theory could explain consciousness in any system, not just brains.
  • Integrated Information Theory (IIT): In a surprising turn of events, Koch’s views took a dramatic shift as he embraced a model coined by neuroscientist Giulio Tononi called Integrated Information Theory. This theory suggests that consciousness arises in any system whose components exchange information in a defined way. According to this theory, even a single proton could possess a speck of consciousness, echoing the ancient doctrine of panpsychism, which believes consciousness pervades everything.
  • Global Network Workspace Theory (GNWT): This theory posits that consciousness emerges when information is broadcast to areas of the brain through an interconnected network. This transmission is thought to occur at the start and end of an experience and is centered around the prefrontal cortex at the front of the brain.

These various theories were vigorously discussed, dissected, and even criticized. Quantum computing expert Scott Aaronson, for example, critiqued the IIT for its mathematical definition of information, arguing that by its standards, a compact disc player running error-correction codes could be more conscious than a human.

The Experiment

A key experiment testing the IIT and the GNWT was conducted and unveiled at the recent ASSC conference to settle the bet. This involved several researchers across six independent laboratories, following a pre-registered protocol and using complementary methods to measure brain activity. Despite their efforts, the results didn’t perfectly match either theory.

The Verdict

Despite the inconclusive findings, both Koch and Chalmers remain optimistic about future research. As Chalmers, now co-director of the Center for Mind, Brain and Consciousness at New York University, said, “There’s been a lot of progress in the field.” He views the process of understanding consciousness as gradually transitioning from being a philosophical mystery to a scientific one. He remains hopeful that an answer will eventually be reached, even though he emerged as the winner of the bet. On the other hand, Koch, now director of the Allen Institute for Brain Science, also expressed optimism despite the unresolved wager. Reflecting on his initial optimism from 25 years ago, he highlighted how technological advancements such as functional magnetic resonance imaging (fMRI) and optogenetics, which allow scientists to stimulate specific sets of neurons, were still young and full of potential. He nostalgically recalled, “I was very taken by all these techniques. I thought: 25 years from now? No problem.”

A Confluence of Science and Philosophy

Though the wager might have ended without a clear victor, the 25-year intellectual journey tells a more nuanced story. This ambitious attempt to understand consciousness signifies a confluence of science and philosophy that has spurred much debate and research in the field. It illustrates how a single question can lead to many hypotheses, extensive testing, and collaborative study from leading experts worldwide. Over the years, the dialogue between Koch and Chalmers has significantly contributed to consciousness studies, pushing the boundaries of our knowledge. While it may seem like a daunting task, the advancements in neuroscience have shed some light on this long-standing question, taking us a step closer to unraveling the mystery of consciousness.

The Path Forward

Despite the strides made so far, the road ahead is still long and winding. As Koch’s initial prediction shows, the complexity of the human brain can sometimes exceed even the most ambitious of expectations. Yet, the desire to understand our own consciousness continues to motivate scientists and philosophers alike, prompting them to revisit, revise, and refine their theories in the light of new evidence and advancements in technology. While the bet may have ended, the quest for the answer continues. Consciousness, the very phenomenon that gives meaning and value to our lives, remains one of the last unexplored frontiers of science. However, as Chalmers said in conclusion, “There’s been a lot of progress in the field.” For more information about consciousness studies and the fascinating interplay between neuroscience and philosophy, visit the Allen Institute for Brain Science’s website.