The Effects of Punishment Schedule on Disfluency Rate

In Experiment I, 40 normal speaking subjects spoke spontaneously. One group of 20 subjects received 100% punishment (time-out) for disfluencies in the first session and 25% punishment for disfluencies in the second session. A second group of 20 subjects received the treatments in the reverse order. In both groups, the 100% punishment produced a marked reduction in disfluencies, whereas the 25% punishment had little effect either on conditioning or extinction of disfluencies. In Experiment II, 20 subjects received the same 100% punishment procedure in all four eight-minute "conditioning" periods. A different 20 subjects received 100% punishment for the first two eight-minute conditioning periods, but only 25% punishment for the last two eight-minute conditioning periods. Subjects in both groups experienced a marked reduction in disfluencies in the first two eight-minute punishment periods. From that point on, the subjects who continued to receive 100% punishment continued to decrease their disfluencies, but the subjects who were switched to 25% punishment remained at almost the same disfluency rate. Neither group demonstrated any marked increase in disfluency during extinction.