Your brain does not process information, retrieve knowledge or store memories. In short: your brain is not a computer
Dr. Epstein laments the emergence and pervasiveness of the IP (information processing) metaphor for the human brain; that is, that the brain operates in the way that modern computers do (though presently with vastly different capabilities). He discusses the difference between a computer’s approach (strict instructions, perfect recall) and a human’s (experiential evolution of knowledge), ultimately concluding that trying to compare a brain and a computer is a flawed undertaking.
Approaching the problem from this angle, Dr. Epstein makes a compelling argument against the ability to compare a brain and a computer directly, though there may be a mismatch in metaphors. A bit in a register and an electrical pulse in a neuron only make sense in the context of a larger system, and it’s the sophistication of that system that determines how those bits and pulses are interpreted. Computer-based systems have a long way to go before matching every level of brain sophistication.
However, when I think about the phrase “the brain is a computer”, rather than approaching the problem from the perspective of algorithms and memory, I think a more appropriate (and more interesting) comparison is with respect to inputs and outputs.
From a computer’s perspective, the concepts of “input” and “output” are straightforward. The device you’re reading this on accepts inputs (via entry points like the touchscreen, keyboard, mouse, or microphone), does *something*, then produces outputs (via exit points like the display, speakers, or vibrating motors). Regardless of what happens in the middle (that is, how the information received via the inputs is changed and turned into information produced via the outputs), the device is, in one way or another, interacting with the physical world.
Computers and humans (and all living beings really) function in a similar fashion, with varying levels of sophistication. Humans, like computers, have several ways to accept information (starting with the five senses) and one fundamental way to produce information (triggering muscles to move parts of our bodies, such as our fingers or vocal chords). The way our brains convert the input that we receive into output via muscle activity is certainly different (for now), but that system is still bookended by physical interactions.
We may be missing the point if we ask the question: “Do computers and humans represent and process information in the same way?” Computers may eventually be designed to process information in the same way as humans and they may not. Instead we should be asking: “Can computers be designed to accept inputs and produce outputs in a way that is increasingly similar to humans?” This is the goal of AI assessments like the Turing Test: to determine if an artificially intelligent system can emulate human cognition and behavior, simply evaluate whether the output it produces can be distinguished from human output.
Ultimately, if you accept that computers are physical objects that accept inputs, process them in some way, and produce outputs, your brain may not be a computer; but you are.