Research Paper Volume 17, Issue 3 pp 778—797

Figure 4. Delay-related effects on DRST performance. Marmosets (blue) show significant delay-dependent decreased DRST performance, whereas macaques (red) do not. Also, macaques have significantly higher performance than marmosets at delays longer than 2 seconds. These results are seen on several measures of performance including (A) average Final Span Length, (B) accuracy on the DNMS (TDL2) portion of the DRST, and (C) accuracy on TDL3 trials. (D) On TDL3 trials, marmosets’ perseverative errors increased in a delay-dependent manner, whereas macaque perseverative errors remained consistent across varying delays. (E) Marmosets’ primacy error rate showed a corresponding delay-dependent decrease, and macaque primacy errors remained consistent across the varying delays. Lightly shaded lines in (A–C) depict individual animal performance as a function of delay. Bold colored lines in (A–C) depict species average performance as a function of delay. mean ± SEM, ^*p < 0.05.