A Mental Multiverse

Consciousness has perplexed humans for centuries. Where does your mind live? Is it a material entity or an abstraction? How does your brain interact with your mind?

In his latest book, The Consciousness Instinct, acclaimed neuroscientist Michael Gazzaniga notes that neuroscience has long been divided into two schools of thought on the topic of how mind and brain intersect. On one side: “the ideas of Descartes and other past thinkers that the mind is somehow floating atop the brain.” On the other: “the ideas of the new mechanists that consciousness is a monolithic thing generated by a single mechanism or network.” These two philosophies, according to Gazzaniga, spurred important scientific advances when they were developed, but may be the cause of the current stagnation in our modern understanding of what consciousness is. “New ideas are needed,” he proclaims, humbly suggesting that his book “takes a shot” at producing them. His humility is deceiving and downplays the novelty of his perspective.

Gazzaniga has rightly been dubbed the father of cognitive neuroscience. He is the director of the SAGE Center for the Study of the Mind at the University of California, Santa Barbara, president of the Cognitive Neuroscience Institute, founding director of the MacArthur Foundation’s Law and Neuroscience Project, and author of several popular science books.

The Consciousness Instinct is entertaining and educational, even radical. In it, Gazzaniga offers a novel perspective on what consciousness is and how it is constructed. The book begins with a historical overview of the field of neuroscience, followed by an introduction to some key concepts about the human brain and its anatomy. Having established this background, Gazzaniga unveils his fresh perspective on consciousness, using surprising and revealing anecdotes from patients he worked with in the past.

Gazzaniga’s history of neuroscience recounts cautionary tales of scientific revelation and humbling blunders with the tone of a wise man warning a wandering traveler. He reminds us that before the first human dissection had been performed, people had to rely on their best guesses of what the human brain looked like. An early anatomist, using his experience dissecting a bull as a guide, made an attempt to describe and sketch the human brain. A persistent relic of his assumptions was the idea that humans have a meshwork of blood vessels, the rete mirabile, which was eventually proved to be false. (An important lesson for modern-day scientists using model organisms!) Gazzaniga leaves the reader with the message that “we have learned over the course of centuries that [it] is hugely important … to check and double-check an earlier claim.” In that vein, he argues that one of the ideas dominating neuroscience today, that the brain is like a machine, could prove even more crippling.

When this notion made its debut, it was groundbreaking. That the material components of the brain could be responsible for generating the abstract mind opened the door for many advances in brain science. The concept allowed people to think of different compartments as being responsible for different parts of thinking and mental processing. But according to Gazzaniga, we have now reached a point where the brain-as-machine idea is hindering progress.

Gazzaniga’s central claim defines consciousness as “the word we use to describe the subjective feeling of a number of instincts and/or memories playing out in time in an organism.” While previous thinkers have suggested that consciousness is an entity in and of itself, Gazzaniga suggests that consciousness is a sort of summary of a person’s integrated experiences and sensations. His book’s major statement builds on the idea of modularity in the brain – that different parts of the brain, or modules, function independently but relay information between one another. He extends this concept to say that each brain module may have its own consciousness.

While this proposition may provoke some skepticism, as one’s life experience feels so unified and singular, Gazzaniga expands on the notion of modularity to strengthen his case. He describes situations in which different modules have independent experiences and may even retain individualistic memories that are unknown to other parts of the brain. His entertaining and at times harrowing anecdotes often rely on split-brain patients — who have had the connections in their brains severed or rendered dysfunctional. One infamous account is that of a Mr. A, a man who “brutally murdered his wife during what was later determined a sleep-walking episode,” leaving him unaware of what he had done. It makes you wonder what your own sleeping self has been up to lately.

The Consciousness Instinct‘s writing style teeters back and forth between informative and playful. Gazzaniga’s descriptions are at times so evocative as to be gruesome. He discusses how one of the biggest impediments to unraveling the anatomy of the human brain was the ancient Greeks’ taboo against human dissection. Gazzaniga as an author has no similar reservations, casually likening the first documented human brain dissection to “slicing a ball of mozzarella di buffala with a dull knife.”

While he conveys many of his ideas in a readable and enjoyable way, it can be tempting to flip through to the end of some chapters, especially during extended descriptions of the philosophical literature. Right when you are about to start counting the pages till the end of the section, Gazzaniga reels you back in with his playfulness. He proclaims that “a lot of works of philosophy are like root-canal work, you just have to get through the damn thing,” quoting philosopher John Searle. And just like that you are pressured to trudge on, as if you’d been caught checking your phone in class.

These attention-calling moments make you wonder how much of the book is an intentional mind game orchestrated by a highly accomplished neuroscientist. In one of his explanations, Gazzaniga stars the word ‘pergola’ in the main text, guiding you to a footnote: “I am going to let you look it up on Wikipedia. That way you can see a picture, too.”

Gazzaniga introduces difficult concepts in clean and simple language. He explains the idea of salience, where “the most ‘active’ module wins the consciousness competition, and its processing becomes the life experience.” He argues that consciousness is not a single entity, but a reflex hard-wired into each compartment of the brain. A person may have multiple simultaneous conscious experiences with only one of them coming to center stage at any moment.

The book’s wonderfully laid scientific and historical foundation makes the reader root for Gazzaniga, and hope that he will be able to communicate the dense concepts that many authors before him have struggled to convey. As the subject matter thickens and the book delves into topics like quantum mechanics, the path becomes more rocky. This is where The Consciousness Instinct ultimately falls short. With disappointment, you begin to wonder: What is a psi function? Will this be cleared up later? Did I miss a footnote telling me to look this up?

Still, Gazzaniga’s book delivers a novel scientific perspective to a broad audience, which makes these minor lapses forgivable. During a visit to my mom’s home I left this book on her coffee table. After some hours of quiet solitude around the house I decided to find her to go for lunch. To my amazement, she was engrossed in the book. When I interrupted, she responded that she was “finally understanding how the brain works!” Her reaction was telling: I had given her books about neuroscience and the brain before, only to find them permanently bookmarked on the second page.

The idea that different modules in the brain each have their own consciousness is very powerful. We can all relate to the feeling that different parts of our brains are competing for our attention. The last time you got a shot, for instance, the nurse may have distracted you with conversation so you didn’t notice the pain. Simple though it may seem, this idea could yet chip away at our modern notion of what consciousness is.

Farah Abdul-Rahman is currently pursuing a Ph.D. in evolutionary biology at New York University. She is an avid over-thinker and enjoys reading and learning about the human mind and its trickery.