Fig. 2.

Behavioral results. (A) Proportion of correct responses as a function of the number of times that each stimulus was presented, plotted separately for each set size. Error bars reflect SEM. (B) Proportion of correct responses as a function of the trial interval since the current stimulus was last reinforced (delay), separately for each set size. (C) Proportion of correct responses as a function of the delay, for early learning trials (one to three correct responses for the current stimulus) or late learning trials (seven or more correct responses). The effect of delay disappears over learning.