Importance of cortical spacing

I’m a real sceptic of supposed dichotomies in brain processing. I think they are often so simplistic as to be misleading and incorrect, and ultimately lead to such profound misunderstandings, supposedly ground in science, as to be actively damaging g (c.f gender differences – aka neurosexism – left/right brain processing, etc). However, I may well be a convert over big picture-fine grained brain processing, which is rooted in the understanding of cortical minicolumns.

The cortex in the brain is arranged into minicolumns, made up of between 80 and 100 neurons sitting in a vertical column (Mountcastle, 1997). The neurons within a column work together to excite or inhibit electrical signals. The fascinating aspect of these minicolumns is that they are regularly spaced throughout the cortex which turns out to have a fairly profound impact on processing skill. Although minicolumns are regularly spaced throughout an individuals cortex (by which I mean, the minicolumns are spaced at the same interval)* this distance varies between individuals. The spacing distance directly correlates with the length of connections that are made between columns: Those with relatively wide spacing between their minicolumns have longer axonal connections down which an electrical signal travels to be passed on; those with relatively narrow spacing have shorter axonal connections (Casanova, & Williams 2010).

This sounds a mundane, even trivial point: if minicolumns are packed tighter together then of course the distance the axons need to span is shorter to connect to the same number of minicolumns as compared to a looser packing of columns. However, the reality is that this is no trivial relationship and the larger impacts of the spacing of minicolumns and the length of axonal connections permeate through to the very way that we experience the world we inhabit.

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Importance of cortical spacing