However, further analysis showed that the VEH low-checkers significantly increased %ActiveCS whereas QNP low-checkers and both high-checker groups did not (VEH low-checker, F 1,5) = 9.46, p < 0.05; all others F 1,5) < 2.58, n.s).s
The VEH high-checker group maintained a strong negative relationship between OLPs and inactive lever presses.
Within the high-checker group, rats that made more OLPs earned more rewards.
Neither QNP/VEH grouping nor high/low-checker status independently affected EOLPs (FT vs. VT, df(1,5): QNP high-checker F = 3.03; QNP low-checker F = 0.87; VEH high-checker F = 0.09; VEH low-checker, F = 2.61; all n.s).s
Thus, for high-checker rats, there was a strong relationship between observing lever presses and task success.
In high-checker rats, one of the effects of quinpirole may be to dissociate the relationship between OLPs and reduction of inactive lever pressing.
There were no differences between prospective QNP and VEH groups within the high-checker group or the low-checker group (Table 1).
Each of the VEH and QNP groups was assigned 6 high-checker and 6 low-checker rats (matched for OLP between VEH and QNP groups).
This difference between QNP and VEH group OLPs with changing response requirement/uncertainty was seen primarily in the high-checker group.
This was only independently statistically significant in the high-checker group (Fig. 4c,d. Table 1), but there was no QV × HLCheck interaction at either PQ49 53 (F 1,20) = 1.54, n.s).s
In contrast, the QNP high-checker group showed a comparable negative correlation between OLPs and inactive lever presses during pre-treatment baseline but not during drug treatment, nor in the long term without quinpirole (see Table 3).
