Thursday, 20 May 2021

Structured Flow on Neural Manifolds (Jirsa et al, 2019)

As I try to develop a vocabulary for an ecological neuroscience, I am looking for two things. First, I'm looking for help from existing methods to help identify real neural parts and processes; so far I've ruled the FEP out for that. Second, I'm looking for an existing dynamical framing to help express whatever ecological psychology figures out about the brain. The jury is still out on whether the FEP is that framing; another option is a development of Kelso's coordination dynamics that invokes structured flow on manifolds. (This paper by Jirsa, McIntosh & Huys was a contribution to the special issue on Ecological Neuroscience). 

As I review the paper, I am going to be trying to figure out if this mathematical framing is going to help. It's not going to be a guide to real neural parts, but it might be the right way to formally describe the real parts we identify by other means. 

Monday, 17 May 2021

Do Markov Blankets Give Us Real Neural Parts?

In my last post, I laid out what I think the rules are for developing a mechanistic model of the neural scale contribution to behaviour. I ended there with a question: what counts as a real neural part? How can we successfully decompose neural activity supporting a given perception-action loop into parts? 

In this post, I want to discuss one potential option: the hypothesis that Markov blankets, a key feature of the free-energy principle approach to neuroscience, can identify and pick out real neural parts. I'll discuss some recent ecological critiques of Markov blankets and some potential answers to the challenges.

Mechanistic Models of the Brain

I'm getting increasingly interested in neuroscience, and how to make it ecological. I also think that the ecological approach is capable of supporting mechanistic explanatory models of behaviour and is the correct scale* at which to ground these models. This means that my current plan is to find a way to add neuroscience as a lower scale part of a model grounded at the scale of the organism-environment system. 

There's a lot going on in that sentence, though, so I want to unpack it a bit to lay out the rules. and the things I currently don't know. 

(*NB I am using scale rather than level throughout because the concept of a level is complicated and currently, I am convinced that scale is a better term. The argument continues, however).