Conscious Reality Is Only a Memory of Unconscious Actions, Scientists Propose In Radical New Theory

Have you ever had that weird feeling of letting your mind wander on a car trip, then not remembering anything about your drive when you arrive at your destination? Or perhaps you’ve struggled to fall asleep as your brain cycles endlessly through intrusive thoughts? Do you ever get “in the zone” while deeply engaged in an activity, like playing music or sports?

These are some of the common experiences that have inspired a team of scientists to dramatically reimagine the evolution of consciousness, which is a state of awareness that humans (and perhaps some other animals) possess about their minds and the world. Led by Andrew Budson, a professor of neurology at Boston University and Alzheimer’s Disease Center and a lecturer at Harvard Medical School, the researches propose that “consciousness is, at its core, a memory system,” and that other functions that we associate with consciousness like problem-solving “developed later in evolutionary history,” according to a study published this month in the journal Cognitive and Behavioral Neurology.

One important consequence of this hypothesis is that all of our decisions and actions are actually performed unconsciously, and then remembered consciously about a half-second later. In this way, our brains fool us into thinking we are making conscious actions in the present, when we are only experiencing delayed memories of events. In fact, what we call consciousness was initially developed to facilitate episodic memory—the brain combining sensory inputs to form a recollection of events—according to the theory. 

For Budson, this new way of thinking about consciousness is informed by his longtime fascination with the science of memory, his clinical experience with patients that have memory disorders, and his personal life as the father of a son with Kanner autism, which affects the ability to form some types of memories. 

All of these threads came together into the novel framework over the past few years, spurred on by conversations with his two co-authors on the study: Kenneth Richman, a philosopher and bioethicist at the Massachusetts College of Pharmacy and Health Sciences, and Elizabeth Kensinger, a professor of psychology and neuroscience at Boston College.

“Once I had the insight that consciousness is part of memory, then the anatomy of consciousness—the neural correlates of consciousness—immediately falls out, because I know the neural correlates of memory,” Budson said in a call with Motherboard. “From all my patient experience, I saw how this fit in so well. It's really a separate insight, but I view it all as falling out of the same central one, which is that there's no single area of the cortex that is conscious.”

Indeed, Budson and his colleagues suggest that the origins of consciousness in memory—and its continued existence across the brain’s memory system—explains all sorts of phenomena. For example, they note that athletes take split-second actions unconsciously first, with the conscious awareness (or memory) of those actions only arriving later.  

“Our theory of consciousness rejects the idea that consciousness initially evolved in order to allow us to make sense of the world and act accordingly, and then, at some later point, episodic memory developed to store such conscious representations,” Budson and his colleagues said in the study. “Our theory is that consciousness developed with the evolution of episodic memory simply—and powerfully—to enable the phenomena of remembering.” 

“We posit further that consciousness was subsequently co-opted to produce other functions that are not directly relevant to memory per se, such as problem-solving, abstract thinking, and language,” the team noted. “We suggest that this theory is compatible with many phenomena, such as the slow speed and the after-the-fact order of consciousness, that cannot be explained well by other theories. We believe that our theory may have profound implications for understanding intentional action and consciousness in general.” 

Scholars have debated the origin and function of consciousness for thousands of years, and the subject now touches a variety of fields that include neuroscience, evolutionary biology, philosophy, and ethics. Some researchers have suggested that consciousness evolved as a mechanism to mediate and control our attention, and others have proposed that it arises in certain parts of the brain. In contrast, Budson and his colleagues suggest that consciousness arises from every region of the brain that is involved with memory.

“Each region that does different things, I think, has its own consciousness,” Budson explained. “There's a visual consciousness and an auditory consciousness,” among others, which “fits in so well with all these patients that I've been taking care of for 25 years,” he said. “I've seen patients with strokes and degenerative diseases in every single part of the cortex, and none of them are unconscious.” 

The researchers note that many previous studies have hinted at the key role of episodic memory in consciousness, but they take this hypothesis to the next level by suggesting that the process of remembering episodes in our life is the foundation of our conscious minds. They note that this origin story of consciousness could explain a host of phenomena, such as our frequent inability to control our thoughts and our capacity to unconsciously complete complex tasks, such as driving or making music. The study could also have major implications for understanding and treating neurodegenerative diseases, such as semantic dementia and Alzheimer disease.

“Our central claim is that consciousness is essentially and originally part of explicit memory,” the team said. We experience the world progressing serially because our conscious memory system creates a linear, coherent stream of experiences from our unconscious, parallel brain processes. We believe that our memory theory of consciousness is useful (and perhaps correct) because it helps explain phenomena that have been recognized as long-standing puzzles for previous theories” and also “helps us understand clinical syndromes, experimental studies, and everyday experiences.”

Of course, this is all just a theory—it may well be disproven. The authors note that past experiments that may indicate unconscious memories at work complicates their idea, but they add that there may be alternative explanations for the observed results.

The team also outlined a host of possible experiments that could help to support or refute their hypothesis. In particular, Budson hopes to conduct studies with individuals who have cortical dementias that would attempt to isolate different aspects of memory, and therefore under this theory, consciousness.

“This would work on the theory I have that when I see patients with dementia, I'm really seeing patients that have diminished consciousness in various aspects,” Budson noted.   

“Who knows? Maybe this whole thing will turn out to be wrong, but to me, it all seems pretty straightforward,” he concluded.

Update: This article has been updated with comments from lead author Andrew Budson.