Dissociation of operant and consummatory responses by trigeminal deafferentation in the pigeon.

Section of peripheral sensory branches of the pigeon's trigeminal nerve abolishes or decreases feeding responses made in an operant conditioning situation without directly impairing performance of an operant key-pecking response reinforced with food. The results are discussed in relation to previous studies of trigeminal function in the pigeon and suggest the possibility of dissociating neural mechanisms underlying feeding behavior and operant conditioning in this species.