We touched on a lot of interesting subjects at the great Salon yesterday

But i would like to dig into one where i think we failed to communicate: what it means to be "close" in genetic space, and why i think it's relevant. (1/n)

@criticalneuro @neuro_data @MelMitchell1

Suppose i am trying to solve eg a prediction task, where I take inputs from a set X and try to predict Y. Maybe X is a set of images, and Y is a set of labels.

Now let's say that i try to solve it with my favorite algorithm, and fail. (2/n)

I take it to one of you, and you say, "Oh, i see the problem, you just need to pre-process your images with this edge detector" or "You just need to use weight momentum to make your network converge". (3/n)

And sure enough, i change a few lines of code (out of many thousands), and it works--yay! thanks!!

So i would say that i was "close" to solving the problem, and that a small change---just a few lines of code-- were enough to fix the problem. Right? (4/n)

So in this example, i think we can agree what "being close" to a solution means. In one case we can summarize the tweak at a pretty high level ("use an edge detector"), whereas in the other case there was a small harder to interpret tweak ("use weight momentum"). (5/n)

But in both cases, we can quantify (or at least, put a bound on) how close i was to a solution by how many lines of code i had to change. Right? (6/n)

Let's consider how this relates to animals. Let's say we have species A that can't solve "cognitive" problem X, and species B which can. Now let's imagine that species A and B are closely related. what this means is that their genomes dont differ very much. (7/n)

In fact, i can quantify exactly how close they are, by measuring exactly how similar their genomes are (in units of nucleotides). Since the genome is just a string of a few billion nucleotides, and there are 4 possible nucleotides (ATGC), distance in nucleotides is just bits(8/n)

So we can say that species A is only some number K bits from being able to solve some problem. In fact, i could in principle determine the minimum number of changes i'd need to make to the genome of species A in order to make it solve problem X. (9/n)

Of course, you might find this unsatisfying, and i'd agree with you. Knowing that A is close to B doesnt necessarily tell you much about *how* species B solves it, or what is different between species A and B. (10/n)

For example, it could be something pretty simple, like problem X requires patience; species B is less impulsive than species A. Or maybe: problem X requires strong auditory-visual integration, which species A doesnt do. (11/n)

So knowing that B but not A can solve it doesnt necessarily tell you what to do next, but it does reassure that you're on right track, and greatly limits space of things you might consider, since diffs between the 2 species must be pretty simple (in units of genes). (12/n)

And that is why i argue that having a system with mouse intelligence is the way to go. To clarify: I'm not asking for a system that can merely mimic what a mouse does, but rather one that at some deep level does it the "same" way. (13/n)

Unfortunately, i can't tell you ahead of time what i mean by "same way". I do believe that using a neural network is "more similar" than trying to achieve mouse intelligence with symbolic AI. But i only have vague hypotheses about what else is missing from current ANNs (14/14)