Figure 2.

(A) Schematic showing the progression of a TUNL trial. The standard TUNL task for training involves a 6 sec delay and a 20 sec ITI, but the length of both of these periods can be altered. (B) Schematic of a Long–Evans rat performing the testing phase of the TUNL task. (C) Schematic labeling distances between stimuli in the testing phase as large (4–5 squares away), intermediate (3 squares away), or small (1–2 squares away). Stimuli within the testing phase of a trial are not presented horizontally, vertically, or diagonally adjacent to one another.