Figure 5.

Event-related electrical stimulation. A, Stimulation was delivered bilaterally (0.2 ms pulses at 120 Hz) for 1 s at the start of the initiate, sample, delay, or choice phases of DMTP. B, Current levels for individual animals (connected points) showing the threshold causing rats to pause while performing a continuous lever-pressing task and the levels used for high and low current stimulation. C, Effects of stimulation at each of the three RIs tested. There were significant effects of current level, trial type (when stimulation was delivered), and the interaction of these factors. There was no significant effect or interaction with the length of the RI. Analyses of simple main effects revealed significant effects of delay and choice, but not initiation or sample stimulation. *p < 0.05 and **p < 0.01, with Bonferroni's correction for multiple comparisons.