Key pecking operant conditioning in detelencephalated pigeons (Columba livia)

The present paper analyzed the acquisition and maintenance of key pecking reinforced with food by pigeons with massive ablation of telencephalon structures (detelencephalated pigeon). The subjects were adult pigeons maintained at 80% of their free feeding weight. Expt. I analyzed the acquisition of key pecking by 3 previously detelencephalated pigeons and 3 normal controls. Expt. II investigated the effects of detelencephalation on the retention of learning through comparisons of pre- and postsurgery key peck rates in schedules of continuous reinforcement. In both experiments the duration of reinforcement was manipulated (20 s and 10 s). The results showed that detelencephalated pigeons are able to learn an operant response and to retain it after telencephalic ablation. Variability in key pecking rate was greater when the lesion preceded conditioning. The data suggest that the telencephalic systems participate in the organization of the key pecking behaviour patterns under this schedule of reinforcement but are not essential for this kind of learning. It is also suggested that subtelencephalic systems participate in the retention of learning.