Figure 1.

Running speeds (cm/s) for the two groups of animals in the preshift training period (6 days). The days represent the 6 day period during which the animals are exposed to either high reward (12 pellet) or low reward (1 pellet). A significant difference between groups was seen only for day 6 of training (Mann-Whitney U test for between group analysis; **= p<0.01 bars denote standard error of the mean).