Phonological priming in adults who stutter

The present study investigated two theories on the etiology of stuttering: (1) stuttering as a phonological encoding deficit (Covert Repair Hypothesis), and (2) stuttering as a central auditory disorder. Two groups of participants were compared: adult males who stutter (ST) and adult males who do not stutter (NST). A phonological priming task was presented visually and auditorily, and speech onset latency (SOL) values were obtained for both participant groups. The results showed the following: (1) the ST group and the NST group did not differ in the number of incorrect responses to the visual and auditory stimuli, (2) the ST participants had significantly longer visual SOL values than the NST participants, but their auditory SOL values were comparable to those produced by the NST group, (3) both groups had significantly longer auditory than visual SOL values, (4) the ST group produced significantly longer visual SOL values than the NST group in all three priming conditions, and they produced significantly longer auditory SOL values in the C- and CV-homogenous, but not heterogeneous condition, (5) the priming effect was more pronounced in the NST group than for the ST group in both modalities, and (6) there were no significant correlations between stuttering severity and speech onset latency. Based on these findings, it was concluded that the present data provide no evidence to support the Covert Repair Hypothesis, and that there is some evidence to support the central auditory disorder theory.