Phase precession

In place cells, a type of neuron found in the hippocampal region of the brain, phase precession is believed to play a major role in the neural coding of information.

John O'Keefe, who later shared the 2014 Nobel Prize in Physiology or Medicine for his discovery that place cells help form a "map" of the body's position in space, co-discovered phase precession with Michael Recce in 1993.

[9] It is now widely accepted that the anti-phase cell firing that results from phase precession is an important component of information coding about place.

[10] The finding that theta wave phase precession is also a property of grid cells in the entorhinal cortex demonstrated that the phenomenon exists in other parts of the brain that also mediate information about movement.

[12] Phase precession in the entorhinal cortex has been hypothesized to arise from an attractor network process, so that two sequential neural representations within a single cycle of the theta oscillation can be temporally linked to each other downstream in the hippocampus, as episodic memories.

Diagram, with a left-to-right arrow marked "1 second" at the bottom. At the upper left are three labels, "Cell 1", "Cell 2", and "Cell 3", in three different colors, and each is followed to the right by a series of tick marks in the corresponding colors. Below the sets of tick marks and above the arrow is a wave function shown as a black line and labeled as "LFP theta". There are thin vertical lines positioned at each peak of the LFP wave, and the space between two of those lines is shaded in blue. The tick marks for Cell 1 tend to occur to the left of those for Cell 2, which in turn tend to be to the left of those for Cell 3, and the tick marks for all three cells occur successively farther and farther to the left between each successive vertical line.
Schematic of phase precession in three place cells . A rat runs left-to-right and the firing of the cells (shown as colored tick marks) is spatially localized, with the three place fields (represented by the three colors) overlapping. The local field potential theta rhythm is shown at the bottom in black. The action potentials of each cell occur earlier and earlier with respect to the theta peak on each successive cycle – this is phase precession. One consequence of this is that within a single theta cycle (blue-shaded rectangle, for example) the cells fire in the same sequence in time as their triggering is organized in space: thus converting a spatial code into a temporal one.