The effect of punishment on a factor I stuttering behavior

On each of five days the subject of this experiment read aloud different material during an 18-min A₁ (base rate), B (experimental), and A₂ (extinction) period. No stimulation was delivered during the first three days. On the fourth day, the nonsense word “norg” was presented noncontingently during the experimental period. There was no statistically significant difference between the A₁ and B periods on any of these four days. On day five, “wrong” was made contingent on Factor I prolongations during the experimental period. As a result, there was a statistically significant increase in their frequency. When the response consequence was removed in the A₂ priod, there was a reliable reduction in prolongations and the frequency closely approximated that found in the A₁ period. These data suggest that response-contingent negative stimulation is contraindicated as a clinical tactic for use with Factor I prolongations. It not only failed to suppress them, it increased their frequency.