Your brain as a computer: outdated metaphor or ripe for revision?

A recent article was published by Robert Epstein regarding the outdated metaphor of comparing a brain to an information processor (or in modern terms, a computer). He argues that the parallel between the human nervous system and computing machines drawn by scientists over the past few decades is long overdue for an upgrade, although it is difficult for many a neuroscientist to even imagine what that alternative could be.

The faulty logic, according to Epstein, goes like this:

Reasonable Premise 1: All computers are capable of behaving intelligently.
Reasonable Premise 2: All computers are information processors.
Faulty Conclusion: All entities that are capable of behaving intelligently are information processes.

Examining this logic, one can see why the argument that humans must be information processes before computers are information processors is absolutely ludicrous, but yet, almost every neuroscientist I’ve met has made this comparison. I admit, that I have even made this analogy myself when explaining my work to the average individual who doesn’t spend their lifetime caring about systems neuroscience. But it still remain unclear what the brain actually does. But Epstein makes a valiant attempt to describe what it CANNOT do.

“We don’t store words or the rules that tell us how to manipulate them. We don’t create representations of visual stimuli, store them in a short-term memory buffer, and then transfer the representation to a long-term memory device. We don’t retrieve information or images or words from memory registers. Computer do all of these things, but organisms do not.”

In this way, Epstein raises a valid point – human brains operate fundamentally differently from computers (the latter which quite literally processes information, creates a set of rules calls a ‘program’ or ‘algorithm,’ and uses these algorithms to do things). When it comes to processing information, it is clear that the brain is not very good at it. You can examine the results of any memory quiz (e.g., drawing a dollar from memory, or the penny memory game), and you’ll quickly realize that your memory bank is not as infallible as you may believe.

But let’s pause here a second (before we start doubting all of our cognitive abilities), and reflect upon what our brains are actually good at. We’re pretty good at recognizing when we’re in ‘good’ vs ‘bad’ environments (aka affective states), learning to avoid situations that cause harm to us, recognizing faces and objects that we’ve seen before (even if we couldn’t exactly draw these items from memory), attending to novelty or uncertainty in the world, and even sometimes we’re good at planning, developing strategies, and pursuing outcomes that we find subjectively valuable. If we want to be a world-class violinist, we could spend 10 hours a day practicing to become an expert and produce Saint-Saen’s violin concerto from memory. If we were the world’s best Go player, we would be capable of beating a computer that uses machine learning algorithms to defeat its opponents. (Granted, 1 of 5 wins is not the ideal example, but the fact that Lee Sedol trumped AlphaGo once is even astonishing). Or perhaps we could be become a numismatist, and with enough practice, develop the ability to identify and draw any coin in our US currency system. These extraordinary examples of superior human processing demonstrate that humans are capable of outperforming computers, in some circumstances.

To say that our our brains do not process any information might be premature, since humans have demonstrated over time that they can develop expertise of a specific subject with many hours of practice, experience, and a little bit of luck and talent. Epstein even admits that we are born with some abilities — humans can sense, use reflexes, and learn. Perhaps the analogy must be revised to say that the human brain is primarily used to learn relevant information and “store” said information memory, although arguably we also must rehearse these representations constantly in order for our brains to maintain these sometimes complex representations. The information that we keep in our bank is what is relevant to us, and the rest is dumped into some type of abyss. With this, I tend to think of the mind workers from the movie “Inside Out,” in which they dispose of memories that are no longer maintained or recalled over time. I mean, when you think about it, humans are receiving a lot information on a daily basis, and there has be some limit for how much we can actively maintain over a period of time.

LTM

This idea is that our memory storage is refined over time is not actually that new. Some research has showing the act of recalling your memories can alter that memory, which affects recall of this same memory in the future (e.g., false memory). So this really just reiterates the point that the brain’s primary function is to learn information (whether that information is accurate or not is irrelevant), which is stored for future use. We don’t just store information willy-nilly every time we learning a new skill or fact and then never touch that piece of information again. If the information is useful in day-to-day life, it will be maintained, otherwise, it will be forgotten in the abyss.

abyss.png

Our individual brains may not be computers, but it would be trite to say that it is incapable of processing any information. Rather, here it seems like the brain selectively processes the information that the its owner chooses to process, or something that evolution has helped us develop automatic reflexes to process. Obviously, there is much variability across individuals regarding these capabilities, but a more interesting point here is that while individuals may specialize in a small bit of information, our collective mind functions someone like a giant computer, where our society can have enough RAM and storage space to process all of the known information in the world. To put more literally in the metaphor, each of our brains are just a single node in a giant neural network, and this network mimics the information processing capabilities of computer.  Actually, when you think about it, viewing the the brain as a single unit in the a network system makes sense, since all individual parts often have a specialized function that contribute to the utility of a larger system (e.g., a ribosome in a cell, a polynucleutide in a DNA strand). So perhaps the bottom line here is this, it is not the brain that is like a computer, but a collection of brains that acts as an enormous an information processor. A novel and crazy hypothesis perhaps, but definitely something to be explored in the next frontier of neuroscience.

Advertisements

Author: Debbie

Cognitive Neuroscientist (in training).

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s