congratulations to another exciting poster, (this one)! Thank you again for sharing the information, I really appreciate what you’re doing and that you’re sharing all this!
After having a look I was thinking about what you wrote and I have a couple of questions. If you could shed some more light on this topic. In the poster there is a sketch of the cortical column, all my questions are related to it
1, What’s in this sketch - just to get a confirmation if I understand this correctly. Let’s say information from the eye is going through thalamus and arrives to L4 (onto proximal dendrites). L4 is also getting grid-cell-like information from L6a (grid cell layer attending to the position of the sensed feature). The information arrives to L4 onto distal dendrites. The L4 cells then activate L3 cells where it is pooled (temporal pooling) and fed further to L5a onto proximal dendrites. L5a is also getting information from L6b which is a displacement-like layer but the information is related to the object, not just the feature and it’s arriving to distal dendrites.
Then, information from L3 and L5a is fed the next level up; while information from L5a travels via collaterals into different regions (like motor region + older brain structures).
So basically, L4 has sensed features preactivated by the position info from L6a. Features are pooled into objects in L3 and that is going to L5a where it’s pooled based on the displacements of various parts of the object. So the next region up in the hierarchy is receiving the information of what object I’m seeing (from L3) and in which state (L5a).
So far so good or did I make a mistake somewhere?
2, What do you currently think is happening in L5b? I’m just curious because I don’t see any information coming in or going out of this layer.
3, I can see the information is fed from L3 to L2. I know these two layers are difficult to distinguish (at least in living tissue), and usually they are refered together as L23. But is there any reason why you’ve separated L23 into two separate L2 and L3 layers? If yes, is the L2 information used anywhere?
4, The green arrow between L3 and L5a in both ways - Shouldn’t there be a green arrow going down from L3 into L5a and a blue arrow going from L5a to L3? I.e. info from L3 arrives to prox dendrites in L5a, but L5a is going back to distal dendrites (and not proximals) in L3?
Like I said, thank you for your contribution, I think this is pretty cool, but I’d just like to check if my understanding is the same as to what you had in mind.
Thank you in advance!