Adam Marblestone: uncertainty

Transcript context

…Speaking of fast weights, is there something in the brain which is the equivalent of this distinction between parameters and activations that we see in neural networks? Specifically in transformers we have this idea that some of the activations are the key and value vectors of previous tokens that you build up over time. There’s the so-called fast weights that whenever you have a new token, you query them against these activations, but you also obviously can’t query them against all the other parameters in the network which are part of the actual built-in weights. Is there some such distinction that’s analogous? I don’t know. I mean we definitely have weights and activations. Whether you can use the activations in these clever ways, different forms of actual attention, like attention in the brain… Is that based on, “I’m trying to pay attention”... I think there’s probably several different kinds of actual attention in the brain. I want to pay attention to this area of visual cortex. I want to pay attention to the content in other areas that is triggered by the content in this area. Attention that’s just based on reflexes and stuff like that. So I don’t know. There’s not just the cortex, there’s also the thalamus. The thalamus is also involved in somehow relaying or gating information. There’s cortico-cortical connections. There’s also some amount of connection between cortical areas that goes through the thalamus. Is it possible that this is doing some sort of matching or constraint satisfaction or matching across keys over here and values over there? Is it possible that it can do stuff like that? Maybe. I don’t know. This is all part of the architecture of this corticothalamic system. I don’t know how transformer-like it is or if there’s anything analogous to that attention. It’d be interesting to find out. We’ve got to give you a billion dollars so you can come on the podcast again and tell me how exactly the brain works.…

Stored transcript either side of the excerpt. The highlighted words are the published quote; the surrounding text is unedited source, never generated.