# Evolution of the neocortex

**URL:** <https://discourse.numenta.org/t/evolution-of-the-neocortex/8387>\
**Category:** General Neuroscience\
**Created:** [April 1, 2021, 7:54am UTC](https://discourse.numenta.org/t/evolution-of-the-neocortex/8387 "2021-04-01T07:54:36Z")\
**Posts on this page:** 1\
**Page:** 6

<div class="post-metadata">

**Author:** ![Casey](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.numenta.org/casey/32/2874_2.png) [@Casey](https://discourse.numenta.org/u/Casey)\
**Post date:** [August 3, 2021, 8:35pm UTC](https://discourse.numenta.org/t/evolution-of-the-neocortex/8387/102 "2021-08-03T20:35:25Z")

</div>

> [@Falco](#):
>
> Side question: What are matrix projection vs core projection?

As far as core / matrix in a generic cortical system, it’s hard because it often kinda conflates with primary / higher order. Thalamic circuits vary a lot connectivity-wise.

> [@Falco](#):
>
> …[presenter Yohan J John](https://www.researchgate.net/profile/Yohan-John-3) replies that there are a little and they are matrix projection to the bottom of layer 3 and top of layer 5".

Matrix projections generally don’t go to L4, so maybe the point is maybe those thin L4s do receive some thalamus but possibly no core thalamus making it not like normal L4, maybe vestigial or normal synaptic connectivity messiness with no useful thalamic input to those thin L4s.

[Previous page](https://discourse.numenta.org/t/evolution-of-the-neocortex/8387.md?page=5)