Fig. 1.

Task 3 (pre-cue delay: 0, 2, 4 s; cue duration: 1 s) performance: (A) Percentage of correct responses averaged across all conditions; the significant Genotype × Diet interaction indicates that the Def diet tended to impair performance of the WT mice but improve performance of the gt/+ mice; (B) percentage of correct responses as a function of session-block; the gt/+ mice performed significantly better than the WT mice early in testing (block 2: gt/+ > WT, p = 0.013); (C) percentage of premature responses as a function of session-block, revealing effects of both Diet and Genotype during session-block 2: (1) a higher percentage of premature responses for the mice maintained on the Def diet (relative to those on the Suf diet) for trials with either a 2 s (p = 0.014) or 4 s delay (p = 0.017), and (2) a higher percentage of premature responses for the WT mice than the gt/+ mice (p = 0.025); and (D) percentage of omission errors averaged across all conditions, showing that the gt/+ Suf mice make a significantly higher percentage of omission errors than gt/+ Def mice (p = 0.008). Abbreviations: WT Suf: wildtype mice fed a folate sufficient diet; WT Def: wildtype mice fed a folate deficient diet; gt/+ Suf: Mthfd1^gt/+ mice fed a folate sufficient diet; gt/+ Def: Mthfd1^gt/+ mice fed a folate deficient diet; gt/+: Mthfd1^gt/+ mice, WT: wildtype mice; *indicates significance ≤ 0.05. Data points are means ± SEM.