External stimulus control of self-stimulation behavior.

Dogs with electrodes implanted in the anterior forebrain region were successfully trained to leverpress for brain stimulation reward upon the presentation of a 1000 Hz tonal conditioned stimulus and to withhold responding during its absence and upon a 2000 Hz tonal discriminative stimulus. The conditioned response extinguished upon removal of reward and was promptly restored when reward became again available. The results are discussed in terms of a conditioned drive induced by the action of the cue. It is proposed that environmental factors play an important role in the initiation and maintenance of self-stimulation behavior. Brain stimulation reward may serve as reinforcer of conditioned instrumental reflexes in an essentially similar way as natural rewards.