Further evidence that rats use ordinal timing in a daily time-place learning task

Rats received morning, midday, and afternoon sessions each day in a chamber located in a room containing distal spatial cues. A lever was mounted on each of the four walls. The rats could work for food on a different lever during each of the three sessions. The rats were able to learn the location of food availability during morning, midday, and afternoon sessions. Results obtained after skipped morning, midday, and afternoon sessions support our contention that rats solve this time-place task using ordinal timing, or knowledge of the daily spatiotemporal sequence of food availability. However, during probe sessions when the predicted location of food availability based on ordinal information conflicted with the predictions based on other types of information, behavioural compromise was evident. It appears that rats use multiple types of information, one of which is ordinal timing, to track the location of food availability in the daily time-place task.