From that video, I see that there is a lot of experimental evidence showing the various cells described in the EC are more global in nature, and that the hippocampus is necessary to create specific contexts. This is contrary to some of my previous understanding (for example, I thought grid cell firing patterns to be specific to the room – but seems they do not actually start out that way). It makes me question the theory of grid cells in the neocortex firing in patterns that are specific to the object – seems like we would need to be looking for a similar mechanism to EC>hippocampus (not just a copy of the EC functions alone)
One experiment that would be interesting (though logistically difficult since it would need to be measured in humans), would be to see if the various types of EC cells described which are global in nature, also fire when a person is playing a video game involving moving a virtual character around an environment.
Another would be exploring a miniature room with a finger. Both of these involve “placing oneself” into the perspective of something else (the virtual character or finger), and presumably operating on a higher level of abstraction than directly walking around a room.
It would be interesting to see if one/both of these older structures of the brain are necessary for these more abstract tasks, and would certainly be applicable to some of the current HTM theory.