20 May 2016

Robert Epstein: Your brain is not a computer

For decades, the neurocomputational metaphor has been an integral part of research that attempts to bridge the gap between the biological structure of the brain and cognition. But it is, alas, only a metaphor. In an essay for Aeon, psychologist Robert Epstein argues that your brain does not process information, store knowledge, or retrieve memories. In short: it is not a computer.

Some choice quotes:
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 into a long-term memory device. We don’t retrieve information or images or words from memory registers. Computers do all of these things, but organisms do not.
And..
[The] IP metaphor is, after all, just another metaphor – a story we tell to make sense of something we don’t actually understand. And like all the metaphors that preceded it, it will certainly be cast aside at some point – either replaced by another metaphor or, in the end, replaced by actual knowledge.
And...
Misleading headlines notwithstanding, no one really has the slightest idea how the brain changes after we have learned to sing a song or recite a poem. But neither the song nor the poem has been ‘stored’ in it. The brain has simply changed in an orderly way that now allows us to sing the song or recite the poem under certain conditions. When called on to perform, neither the song nor the poem is in any sense ‘retrieved’ from anywhere in the brain, any more than my finger movements are ‘retrieved’ when I tap my finger on my desk. We simply sing or recite – no retrieval necessary.


It's a fascinating and provocative essay. I'd be very curious to hear thoughts on it from writers I follow like Steve Novella (neuroscientist) and George Lakoff (cognitive linguist).

However, there are a few issues that I'd raise with this essay.

The first is that while metaphor is of course not literal — computers don't literally store and process information — metaphors are nonetheless integral to our human process of reasoning. As counter-intuitive as it might be, we literally cannot reason without the use of metaphor. These range from primary metaphors like big is important ("tomorrow is the big day!") or love is closeness ("we grew apart over the last year") and many more, to conceptualizations of time as spatial movement ("the holidays are approaching quickly") or causation as motion ("FDR's leadership brought the country out of depression"). The fact that we conceptualize the brain using the neurocomputational metaphor is not in itself fault, such that it allows us to understand and predict states of cognition. But Epstein is likely correct in that the metaphor is inherently limited. That's why we need a cross-disciplinary study of the mind and brain from neurobiology, neurocomputation, and cognition.

I'm also skeptical of this claim:
[There] is no reason to believe that any two of us are changed the same way by the same experience. If you and I attend the same concert, the changes that occur in my brain when I listen to Beethoven’s 5th will almost certainly be completely different from the changes that occur in your brain.
Our shared biology constitutes a reason to think that responses to similar experiences are at least somewhat the same. Perhaps Epstein simply means that the configurations of neurons that change over a lifetime are inherently widely varied due to our vastly varying experiences; but we don't have to throw the baby out with the bathwater — the same parts of the brain likely undergo similar structural changes in response to similar stimuli, simply because our brains are — by our shared, human DNA — very similar organs.

Those are my thoughts, at least. But it's a provocative topic, certainly.

Full essay: The Empty Brain

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.