A Neural Cone?

Physics and Light

One of the coolest concepts I encountered in physics was the “light cone”.

That cone in the picture is a depiction of the speed of light. And since the speed of light is the speed limit of the universe, things outside of that cone cannot be causally related to the thing at the vertex of it.

In other words, light traces out the absolute limit of its own influence - and the influence of anything/everything else in the universe.

So if you “see” an event outside of that cone, it cannot be causally linked to the event at the vertex.

Neuroscience

I’ve wondered if we can make a similar concept for neuroscience. I remember asking on twitter a few years ago, and there has certainly been some work done in this space ¹.

While I try to search for it, I figured I’d outline the broader idea here.

One key thing to note: the cone won’t look clean in any non-trivial neuronal network ². That is, the connectivity between neurons, or the topology of a neuronal network, will make the cone irregular, curvy, jagged even.

Why? Because not all nodes come together in a uniform grid - like we think space does. Even if it has a bigger curve, the local relationships are pretty uniform.

Causality in the Clinic

We can use somesuch cone to constrain causal influence - ideally in the clinic. You see, the clinic isn’t an experiment - it can’t be. Patients are not Petri Dishes. So we will never have the ability to tease apart causal influence in the rigorous manner of the day.

So we have to do the next best thing ³. We have to triangulate to the answer by mapping out where the influences cannot be.

So, I’m going to spend a bit more time coding this up, and maybe even writing an NIH-style grant for it. But hopefully you see the potential here just enough to pay attention ⁴.