Fig. 1.

Everyday event arena protocol. (A) The training protocol consisted of 2 sample trials (STs) followed by a probe trial. During ST1, different startboxes (orange) were used for the first pellet and rats were trained to dig for pellets and carry these (dotted lines show representative trajectories) to a fixed home-base (blue). When retrieving the second pellet, rats left from the same home-base and returned with the pellet. ST2 was the same as ST1 but a different startbox was used. After a delay (either 30 min or 24 h), a CT1 was performed to determine whether the rats preferentially dug at the correct location. (B) Rats (n = 14) learned the task and maintained a stable above-chance performance from session 16 (S16). (C) Memory retention declined from well above chance at 30 min to chance level at 24 h (n = 14). Overnight forgetting is an important characteristic of episodic-like everyday memory. Means ± SEM and individual animal data plots. Dashed line (in B and C) indicates chance level. ns, not significant. *P < 0.05, ***P < 0.001.