Analysis of distinct sequential learning phases. (A) Number of head entries as indicators of associative learning in magazine training (M1–4) show an overall significant effect of EPO treatment compared with placebo. (B) Number of nose pokes in the operant learning phase (S1) as well as (C) percentage of correct nose pokes in the discriminant learning phase (S2) were higher in the EPO-treated compared with the control group (placebo plus no-inject). (D, E) Initial cognitive performance in the 5CSRTT was better upon EPO treatment in the 16-sec and 8-sec stimulus duration phases, but no longer in the 4-sec phase (F); n = 14–28 per group; data presented as mean ± S.E.M.; all significance values refer to post hoc tests which were only significant if ANOVA was also significant; in (E), only ANOVA was significant (P = 0.03).