The Brain as a Prediction Machine: The Key to Consciousness?

In attempting to resolve the seeming enigma of how the brain produces consciousness, it’s important to first understand "What Actually Is a Thought? And How Is Information Physical?" Thoughts are physical representations or maps. The mind is a kind of map. The brain, and its functional product, the mind, evolved as a map of the body’s relation to its external environment.

More evolved brains, such as human ones, can integrate past sensory experiences to form representations of things that are not presently “out there”—predictive simulations.

Beliefs are a form of predictive modeling.

Anil Seth, a neuroscientist at the forefront of the serious science of consciousness, explained and developed the concept of the brain as a prediction machine in his book Being You: A New Science of Consciousness .

Seth suggested that even our perceptions of what is presently “out there” are, in a sense, just predictions or simulations (what he refers to as “controlled hallucinations”). These are formed by a continual process of updating predictions or assumptions (“best guesses”) as to what the sensory data are perceiving.

As Seth explained in his popular TED talk:

“Perception—figuring out what's there—has to be a process of informed guesswork in which the brain combines these sensory signals with its prior expectations or beliefs about the way the world is to form its best guess of what caused those signals. The brain doesn't hear sound or see light. What we perceive is its best guess of what's out there in the world.”

According to this theory, what we perceive is strongly shaped by top-down expectations / predictions, not just by bottom-up sensory input.

In his book, A Thousand Brains, Jeff Hawkins elaborated on how the brain’s knowledge is stored as numerous models or maps of the world. Research by Hawkins’ group has focused on how the brain has thousands of complementary models of each object it perceives.

He calls this the “Thousand Brains Theory of Intelligence”. Each model operates as a reference frame, physically stored in a tiny cortical column. These complementary reference frames provide “what” and “where” information; acting all together, they provide information about how the different aspects of the object relate to each other.

So how come we don’t feel like we’re composed of a thousand brains, each with their own independent little model of the world? How come our consciousness feels unified? This is known as the binding problem.

Hawkins’ “Thousand Brain Theoryproposes that the cortical columns work together through their connections with each other, some of which are long-range connections crisscrossing the entire neocortex.

Through a process akin to “voting,” the different simultaneous models established by different cortical columns encoding perceptions from different reference frames reach a “consensus” best guess (an algorithmic inference) as to what the object is that is being perceived, based on prior learned information (e.g. “the only thing that is consistent with what we’re all perceiving right now, based on the input from all the different senses and from all our different reference frames, is a coffee cup.”).

The fact that expectations fundamentally shape perceptions and beliefs explains many of the brain’s most successful features, as well as its many problematic bugs.

Seeing is believing. But our perceptions are sometimes wrong. This may lead us to form mistaken (and often, intransigent) beliefs. Equally, believing is seeing—that is, our perceptions are shaped by top-down expectations/assumptions about what we are seeing, hearing, etc. When our prior expectations are mistaken, they powerfully influence us to perceive things in mistaken ways.

Magicians skillfully exploit our perceptual expectations to entertain and amaze us, as do psychics—some of whom are charlatans, others are themselves true believers—victims of self-deception as much as they are responsible for deceiving others.

We, humans, are highly suggestible, which, for many, combines with an incomplete understanding of science and other complex subjects (and an overestimation of that understanding), leading to beliefs in paranormal phenomena, mystical experiences, and other weird beliefs (including conspiracies), confused as to what is real and what is not.

Mistaken expectations play a role in many mental disorders. Anxiety and depression, the most common mental disorders, are characterized by, and some would say partly caused by, faulty expectations of, or predictions about, the future—overestimation of threat or failure.

Furthermore, expectations and unconscious biases in processing bodily sensations play an important role in functional neurological disorders (conversion disorders), and in other psychosomatic disorders. And expectations most certainly play a central role in the ubiquitous phenomenon of placebo response.

• Psychology has focused a lot on how the past causes our present behavior. But the future can cause the present too, via prediction / simulation.
• The brain is constantly making predictions. Consciousness enhances the brain's ability to form predictive models of the environment and the self.
• Faulty top-down influence of expectation on perception shapes illusions, weird beliefs, anxiety, depression, psychosomatics, placebos, and more.