the effect of knowledge of result feedback timing on speech motor learning in healthy adults

Objectives: the current study mainly aimed at studying the effect of knowledge of result (kr) feedback timing and result-estimation opportunity before receiving delayed kr on learning a new speech motor skill in monolingual healthy adults. methods: thirtynine persian healthy adults were randomly divided into three groups. each group received immediate kr, delayed kr (after eight seconds), or delayed kr (after eight seconds) with selfestimation of the result in the delay interval. all three groups received verbal kr feedback. participants were trained to produce a french phoneme (/ɪn/) in the context of words in four training sessions. the correct production of the target phoneme was judged by a bilingual persian-french examiner holding an academic degree in french language teaching. later, a transfer test and two retention tests were administered. the two retention tests were administered one day and two weeks after the last training session respectively. results: the effect of feedback timing on motor performance and motor learning was examined by repeatedmeasures anova. performance in both acquisition and retention phases was significantly different between groups (p=0.04 for both phases). oneway anova was used to investigate the transfer of learning (p=0.001). tukey test results indicated that the groups 1 and 2 were different in both acquisition and retention phases and all three groups were different in transfer test.discussion: the results showed that the immediate kr is beneficial for the acquisition phase, and delayed kr is more beneficial for the retention and transfer tests compared with immediate kr.