At each generation of selection, all mice were tested first on the hole-board and, the next day, in the object preference task. One to 3 days later the mice were tested for novel environment preference, and 1 day later they were tested for spontaneous alternation in a Y-maze. For simplicity, and because of nearly identical results at all generations of selection, only the results from selection generation 5 are shown in Fig. 3. Although strong overall object preference and novel environment preference were observed, there were no differences between the selected lines in the degree of preference (Fs1,132 < 1.04) and no effect of replicate or line by replicate interaction (Fs1,132 < 2.70; P > 0.1). There were likewise no differences in the numbers of HEB and LEB mice that chose the novel arm in the spontaneous alternation task (χ2 < 1.15; P > 0.28).
