Extended Data Fig. 9: Phase precession can exist without firing rate modulation.
From: Theta phase precession supports memory formation and retrieval of naturalistic experience in humans
Simulation based on the model of Mehta et al, 2002. (a and c) The spikes in this model (green dots) occur when the down-swing of the fluctuating inhibitory current (red) crosses the excitatory current (blue). Like in the original implementation, in this simulation neurons fired only briefly when excitation first exceeds inhibition. We implemented this feature by assuming a refractory period of 60 ms. Note that in both cases the firing rate of the neuron remains the same (number of spikes = 6). The difference is that the activation current is constant current in (a) and ramping in (d), resulting in no phase precession (b) and phase precession (d), respectively.
