Maintenance of adaptive strategies to oral-articulatory perturbations

Abstract

The present investigation examined whether speakers would adapt to a palatal perturbation in [s] production subsequent to focused practice, and whether the compensatory motor programs developed would be immediately available after a short period of rest. The fricative [s] was produced in three vowel contexts [si sa su] with and without a specially designed artificial palate in place at three time intervals: at the onset of the experiment, after a one-hour period of [s]-intensive practice with the palate in place, one hour later after a period of rest without the palate in place. Recordings of [š] under normal speaking conditions were also made at each time interval to examine any potential carryover effects. Preliminary analyses revealed that centroid frequencies of the [s] productions were significantly lower in the perturbed condition relative to normal upon first insertion of the palate. After the practice period, centroids in the two conditions more nearly approximated one another. However, after a rest period, speakers’ fricative productions were again impaired by the presence of the artificial palate. Results are discussed in relation to the development and retention of adaptive articulatory programs in speech motor control. [Work supported by NSERC.]