Maybe L5tt represents shifts in the conscious cortical representations. To clarify, conscious representations means ones which spread to a lot of the cortex. E.g. a sound which you notice or a muscle movement.
There’s lots of papers on that sort of thing. I just think shifts solve a couple problems with displacements:
- L5tt responds to a single stimulus, before there’s a displacement.
- In barrel cortex, L5tt doesn’t seem to represent displacements. It’s not so exact. At best, it can represent location relative to the head. Probably anyway. These things are hard to interpret.
Shifts might fulfill theoretical needs for displacements via shifts between locations.
Prediction: L5tt represents different things, like objects, locations, or behaviors, in different experiments. It depends on the shifts in conscious representation which each experiment causes.
The current thinking at Numenta is L5tt represents displacements. I really like that idea because displacements are useful for identifying the world’s structures and for moving the body. That dual-purpose explains why L5tt cells conflate sensory responses and motor output, which’d seem really weird otherwise.