Programmed and experienced delays to reinforcement following AcbC lesions made after initial training AcbC-lesioned rats experienced slightly longer response-delivery and response-collection delays than shams in the 20 s condition. Lesions were made after initial training; postoperative experienced delays are plotted. (Compare Figure 6, in which rats had no preoperative experience of the task.) (a) Mean experienced response-delivery delays (one value calculated per subject). When the programmed delay was 0 s, reinforcers were delivered immediately so no data are shown. There were main effects of lesion (F1,21 = 9.14) and delay (F1,21 = 87.5, p < .001) but no lesion × delay interaction (F1,21 = 1.91, NS). When the programmed delay was 10 s, the experienced delays did not quite differ significantly between groups (F1,10 = 4.61, p = .057), but when the programmed delay was 20 s, AcbC-lesioned rats experienced longer response-delivery delays (F1,11 = 6.29, * p = .029). (b) Mean experienced response-collection delays (one value calculated per subject). There was a lesion × delay interaction (F2,31 = 3.85, p = .032), as well as main effects of lesion (F1,31 = 11.9, p = .002) and delay (F2,31 = 171, p < .001). AcbC-lesioned rats did not experience significantly different delays when the programmed delay was 0 s (F1,10 = 1.74, NS) or 10 s (F1,10 = 1.49, NS), but experienced significantly longer response-collection delays when the programmed delay was 20 s (F1,11 = 13.7, ** p = .003).
Cardinal and Cheung BMC Neuroscience 2005 6:9 doi:10.1186/1471-2202-6-9