The effects of a contingent light-flash on stuttering and attention to stuttering.

The hypothesis that a light-flash made contingent on stuttering would reduce stuttering to the extent that it called subjects' attention to their stuttering responses was investigated with two adult female stutterers. Attention to stuttering was measured by asking subjects to depress a switch each time they detected a stuttering in their speech. For one subject, the contingent light produced a marked reduction in stuttering but had no effect on switch-pressing. For the other subject, the light had little effect on stuttering but resulted in an increase in switch-pressing. For both subjects, reductions in stuttering occurred when they were asked to note their stutterings by pressing the switch. The results suggested that the effect of the light on stuttering was not due to its role in calling attention to stuttering.