Extended Data Fig. 2: Examples of failure of landmark control.

a, Top, experimental gain, G (blue), and hippocampal gain, H (yellow), for epochs 1–3 of a session in which G_final was 0.231. Note that the two curves overlap until about lap 40, when they start to diverge. Middle, spikes from three putative pyramidal cells (coloured dots) in the laboratory frame. Alternate grey and white bars indicate laps in the laboratory frame. Bottom, the same spikes in the landmark frame. At the point of landmark-control failure, the place cells stop firing at a particular location in the landmark frame, and instead start drifting in both laboratory and landmark frames. Alternate grey and white bars indicate laps in the landmark frame. b, Second example, from a different rat, for a session in which G_final was 0.1 (same format as a). c–e, Trajectory of hippocampal gain, H, for three rats for all sessions in which landmark control failed. The hippocampal gain generally starts near to one, and then diverges from the experimental gain trajectory (not shown) during the session.