SERIAL REVERSALS OF CONCURRENT AUDITORY DISCRIMINATIONS IN RATS

Five albino rats were exposed to a go/no-go discrimination procedure t hat presented three different tones (Set 1) as positive stimuli and th ree other tones (Set 2) as negative stimuli. In initial training, all animals reliably discriminated the tones, that is, they pressed a resp onse lever consistently in the presence of the three positive stimuli and they pressed much less often in the presence of the three negative stimuli. Thereafter, the reinforcement contingencies were reversed. T he three positive stimuli became negative and the three negative stimu li became positive. Four of the five rats acquired the reversed discri minations. These four rats were then exposed to two or more additional contingency reversals. Two animals showed savings; they met the acqui sition criterion more quickly on later reversal problems. Overall, the results show that albino rats have a greater capacity for acquiring a nd reversing auditory discriminations than has been reported previousl y.