Figure 4.

Increasing trial numbers enhanced rate of learning a visual pairwise discrimination task not involving top-down processing in wild-type (WT) and M₁ KO mice. (A) Common stimuli used for pairwise discrimination: Stimulus 1, “marbles”, and Stimulus 2, “fan”. (B) Wild-type mice do not show an inherent preference for either stimulus; M₁ KO mice show a slight preference for Stimulus 1 when responding on either stimulus was reinforced. (C) Percent accuracy showing rate of learning and (D) survival plots showing acquisition across 12 consecutive days in wild-type (black) and M₁ KO (gray) mice when discriminating between relatively equal salient stimuli (Stimulus 1, S+; Stimulus 2, S−) when exposed to 60 (circles) or 100 trials (triangles). (E) Percent accuracy and (F) survival plots across 12 consecutive days following vehicle or BQCA administration in wild-type mice completing 60 trials per session. open symbols, p < 0.05 compared to vehicle-treated wild-type group exposed to 100 trials per session; *, p < 0.05 compared to vehicle-treated wild-type group exposed to 60 trials per session.