Discrimination learning and stimulus generalization in rats with hippocampal lesions

Rats with hippocampal lesions and sham operated control animals were trained on a go-no-go tone discrimination. For half of the animals of each group the tone was the positive stimulus while for the other half the tone was negative. The hippocampal tone negative group took the greatest number of days to learn the task. Tone generalization tests administered the day after the learning criterion was reached did not yield any differences in either excitatory or inhibitory stimulus control between the hippocampal and sham animals.