False functional inference: what does it mean to understand the brain?
A few days ago Eric Jonas and Konrad Kording [pictured here] (J&K) posted a thought-provoking paper on bioRxiv entitled “Could a neuroscientist understand a microprocessor?” It’s been circling round my head for most of the weekend, and prompted some soul searching about what we’re trying to achieve in cognitive neuroscience.
The paper reports on a mischievous set of experiments in which J&K took a simulation of the MOS 6502 microchip (which ran the Apple I computer, and which has been the subject of some fascinating digital archaeology by the http://www.visual6502.org/ team), and then analysed the link between it’s function and behaviour much as we might do for the brain in cognitive and systems neuroscience. The chip’s “behaviour” was its ability to boot and run three different sets of instructions for different games: Donkey Kong, Space Invaders and Pitfall (as a side note, exploring this sent me down the rabbit hole of internet emulations including this one of Prince of Persia which occupied many hours of my childhood). While their findings will not necessarily be surprising for a chip designer, they are humbling for a neuroscientist.
By treating the chip like a mini-brain, albeit one in which the ground truth was fully known, J&K could apply some canonical analysis techniques and see what they revealed. The bottom line is that for most of these analyses, they were either downright misleading or ended up producing trivial results….
(Thanks to Chris Frith for bringing this to our attention.)
BONUS: A recent essay by Robert Epstein, in Aeon: “The empty brain — Your brain does not process information, retrieve knowledge or store memories. In short: your brain is not a computer“