Learning criterion was set to 80% on two consecutive sessions including 20 trials per session.
We used the Wilcoxon rank-sum test to compare the number of trials/days to reach learning criterion between groups.
Compared to controls, rats with hippocampal lesions made a significantly higher proportion of errors and took significantly longer to reach learning criterion.
Compared to control rats, rats with hippocampal lesions required a greater number of inbound trials to reach learning criterion on the inbound component of the task (p = 0.019), and they also required a greater number of outbound trials to reach learning criterion on the outbound component (p = 0.0095).
Subjects learned a discrimination between 2 and 3 objects in the absence of any manipulation of the stimuli; after animals had achieved learning criterion they were tested without reward while controlling for one perceptual non-numerical variable at a time.
Subjects learned discrimination between 4 and 8 objects in the absence of any manipulation of the stimuli; after subjects reached learning criterion they were tested without reward while controlling one continuous variable at a time.
Learning criterion was three consecutive correct trials.
When the piglets had reached a preset learning criterion, they were trained on reversal of this problem (i.e., instead of responding on the side where the stimuli appeared, responding at the opposite side was rewarded).
Some birds failed to meet the learning criterion in some phases; for animal welfare reasons, these birds were progressed to the next phase after they reached a maximum number of sessions (at least 50 sessions, see Results for details).
The learning criterion remained at 100%%.
The transition from one step to the next depended on the achievement of a learning criterion.
