Trends

Previous models of place cell generation by summing of grid cell inputs have been called into question by recent results.

The phase precession of place cells depends on the MEC and thus probably grid cells.

Phase precession is an expression of theta sequences, in which place cells fire in order during a single theta cycle.

The theta cycle can be broken into two parts: during the first half of the theta cycle, current position is represented; during the second half of the theta cycle, the system performs mind-travel to upcoming locations.

Mind-travel during the second half of theta is hypothesized to be driven by grid cells given their universal representation of spatial adjacency.