Error Prediction in Acquired Apraxia of Speech

Six participants with acquired apraxia of speech predicted whether or not they would produce correctly 180 words that varied from one to three or more syllables in length and from low to high abstractness. Participants predicted they would produce very few errors (6.3%), but produced a much higher number (27%). Accuracy of predicted errors also was very low, with only two participants correctly predicting more than 10% of their errors. Error analysis revealed that participants consistently produced more errors as a function of both increasing syllable length and word abstractness. However, a contrasting pattern was found in the error prediction results. Participants predicted more errors as a function of increased word abstractness, but not as a function of word length. Results suggest that speakers with apraxia have limited knowledge of motor complexity factors, such as word length, that affect speech production.