Edited by Amy Brady
NONFICTION
Putting Ourselves Back in the Equation: Why Physicists Are Studying Human Consciousness and AI to Unravel the Mysteries of the Universe
by George Musser
Farrar, Straus and Giroux, 2023 ($30)
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For a time, in the late 1980s, it looked like the field of neural networks was dead. Its researchers, who were seeking answers about consciousness by creating interconnected webs of computing units, could not overcome the limitations of their tools. Hardware did not compute at fast enough speeds. Software was too simplistic. It wasn't until the 2010s that technology had advanced far enough to allow theories “that seemed almost frozen in amber” to be explored further.
That scientists could leap far ahead into new theoretical territory yet make little experimental progress in computational neuroscience underlines the challenges and complexity in explaining the workings of mind and consciousness. In Putting Ourselves Back in the Equation, journalist and Scientific American contributor George Musser brings readers along on this quest, tracking the development of different ideas and suppositions that aim to elucidate how consciousness might have arisen and what processes inform—if not create—our perceptions of reality.
Investigating the mind and confronting the “hard problem” of consciousness necessarily require the collision of disciplines. The field's most significant researchers seem to have stumbled into it from myriad backgrounds—semiconductors, psychiatry and cosmology, among other fields—and it's Musser who wanders into these scientists at conferences, in cafeterias and in train cars to get details on the latest findings. His book is structured as an overview in the form of an expansive series of questions. It begins with the mechanical and local—say, how a brain might anticipate information—and progresses toward ones that threaten any simplistic notion of reality, such as: What if we're only a floating blob mind that briefly materializes in the death throes of a universe?
It's no surprise that the study and building of neural networks have become central to learning about the mind. Unlike simple computers, these networks can involve many parallel systems of interwoven logic, much like our brain and its wiring. Simulated neurons in a network, for instance, allow for the dynamism of feedback, enabling the network to form associations and learn algorithmically. What we consider as consciousness could be an emergent property of these highly organized, interconnected systems.
Musser takes two leading theories of mind that have emerged from the study of these networks as avenues of exploration and explanation. Karl Friston's predictive coding theory says that our consciousness arises from the constant updating of a processing pipeline that both receives and predicts information—that is, our expectations also make our reality. Meanwhile Giulio Tononi's integrated information theory proposes that consciousness is the result of neural networks working together in harmony. It's the systemic unity that unleashes an emergent property of conscious awareness greater than the underlying parts alone.
These two theories recurrently pop up in the book as Musser reveals that our quest to understand our mind is also a fundamental investigation of the physical universe we believe we know. It turns out that our subjective consciousness appears to have a big role in the finer workings of physics at large—especially at the quantum level, where there may be no objective outcomes, only subjective experiences. Two philosophers, David Chalmers and Kelvin McQueen, have suggested that the mind itself creates a quantum collapse effect. Others, of course, disagree. One cognitive scientist thinks it happens the other way around—that the collapse effect is what creates consciousness.
Musser shows that prodding at the level of infinitesimal quantum phenomena uncovers larger questions that require a fuller understanding of our consciousness. Is there an objective reality, or is it all in our heads? Is there such a thing as free will? Is spacetime only a projection of our brain's neural processes?
It's possible that we inhabit a perspectival universe dependent on the presence of an observer. It's possible for us to attain agency and a sense of causality at a high level of organization that frees us from the utter chaos of particle particulars. It's possible that we cannot remember the future, because our memories need to first become quantum entangled with our world. We think, therefore, we're possibilities nested within probabilities. In thinking about thinking, many devoted thinkers get seemingly trapped in thought experiments in a strange, self-contradicting loop. When in doubt, cry “empirical incoherence” and make a run for it.
