Similar to the acquisition of cue discrimination in neurons activated by the CS+ and CS−, control, but not DAT-NR1 KO mice, acquired cue discrimination in neurons inhibited by these stimuli.
At every level of reinforcement, the 4 min SΔ groups acquired the discrimination more quickly.
Rats with a perirhinal cortex lesion needed significantly more days to attain the criterion in the relearning of a pre-operatively acquired object discrimination task than the control rats and rats with a hippocampal lesion.
Rats with a hippocampal lesion required more days to attain the criterion than the control rats to relearn the pre-operatively acquired place discrimination task, and they had fewer correct responses in the first three sessions with new discriminanda than the control rats.
Our findings are compatible with a study (39) that used a task analogous to the SD and SR stages in the attentional set-shifting task but with probabilistic contingencies; patients acquired the discrimination but were impaired on reversal.
Sham (N = 11) and HPC mice (N = 9) acquired the discrimination over the course of training (effect of (16 trial) block: F 3,54) = 77.3, P < 0.0005) with both lesion groups showing a mean performance greater than 90% correct on the last block of training (Fig. 6a, right panel).
The relationship between discrimination and reversal learning speeds was positive, meaning that birds that took more blocks to acquire a discrimination also took more blocks to acquire the reversal.
If the MTT lesions selectively disrupt the processing of self-movement cues, then the MTT leisoned animals should acquire this discrimination at an equivalent rate to control animals.
A notable exception is the positive correlation between trials to acquire a discrimination and trials to acquire its reversal observed in a recent study of song sparrows, Melospiza melodia (Boogert et al., 2011).
They successfully acquired a simple discrimination, with and without additional delays (Experiment 1), and a non-spatial, conditional discrimination, with and without a discontiguity between the start arm conditional cue and the goal arm cues (Experiments 3 and 2, respectively).
