Yes, very much so. If you read much of what I have been posting I have covered both the reach of dendrites and L2/3 lateral connections several times.
I have been conversing with @gmirey for some time on this general topic. We endeavored to get a sense of the scale of the relative dimensional quantities of the temporal layer, inputs and cell/column spacing, number and range of the connections.
You know - the basic facts of making a realistic model. Some of what was discussed was what is known about reach and density of the dendritic arbor in the “input” layer.
We established the key factors would be: what is the spacing of the ascending cort…
Spoiler alert: about 0.3 mm, or eight mini-columns radii.
This post gives a simpler and more visual presentation:
If you think of the dendrite festooned with synapses - it is an input device to sample the local environment. A given dendrite can only reach about 250 µm away, or a circle of 500 µm in diameter reach for a given mini-column. Remember that these mini-columns are pitched about 30 µm apart so a dendrite can reach about 8 mini-columns away in any direction, or about 225 mini-columns total.
The lateral connections allow for a distant winning cell (beyond the reach of the dendrites) to add input/ex…
And this related post shows how I think the lateral connections vote to reinforce each other and go on to form my dreaded hex-grid.
In this post, I laid out a lot of the basic geometry and spacing of the relationship between mini-columns and sub-components.
I made this top-view picture to show the relative spacing between the reach of mini-columns dendrites in relation to the size of the mini-columns. The blue circles are mini-columns, and the black circle is the reach of the input dendrites of the “center” mini-column.
[dendrite%20area]
In the HTM into hex grid post I showed a side view of the pyramidal neurons with the…
Hex-grid? What is this hex-grid you speak of?
Consider this example of the possible set of input patterns on L1 that might be found on a given section of cortex:
[Input%20pattern]
We would like the trained mini-column to vote on what pattern they might be sensing and settle on one of these sets of output patterns on the projecting axons from L2/3:
[Output%20pattern]
So in this given section of the cortex (spanning hundreds of mini-columns) the alignment between these input and output pattern is this:
[Combined%20Patterns]
I want th…
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