Carlin F. Hageman

Visuomotor Tracking Abilities of Speakers With Apraxia of Speech or Conduction Aphasia

This investigation examined the visuomotor tracking abilities of persons with apraxia of speech (AOS) or conduction aphasia (CA). In addition, tracking performance was correlated with perceptual judgments of speech accuracy. Five individuals with AOS and four with CA served as participants, as well as an equal number of healthy controls matched by age and gender. Participants tracked predictable (sinusoidal) and unpredictable signals using jaw and lip movements transduced with strain gauges. Tracking performance in participants with AOS was poorest for predictable signals, with decreased kinematic measures of cross-correlation and gain ratio and increased target-tracker difference. In contrast, tracking of the unpredictable signal by participants with AOS was performed as well as for other groups (e.g. participants with CA, healthy controls). Performance of the subjects with AOS on the predictable tracking task was found to strongly correlate with perceptual judgments of speech. These findings suggest that motor control capabilities are impaired in AOS, but not in CA. Results suggest that AOS has its basis in motor programming deficits, not impaired motor execution.

Dementia and identification of words and sentences produced by native and nonnative English speakers.

The accurate identification of 30 words and 15 sentences spoken by native English, Taiwanese, and Spanish speakers was compared for 16 persons with and 16 persons without dementia. Statistically significant differences for words and sentences occurred between groups of listeners.

Auditory comprehension of stutterers on a competing message task

This study investigated auditory processing in ten adult stutterers and ten nonstuttering adults using a competing message task derived from the Revised Token Test (RTT), and the RTT itself. Quantitative and qualitative (pattern analysis) measures of each groups performance were examined across and within listening conditions. Stutterers were found to perform significantly poorer than nonstutterers on the competing message task, but the qualitative performance did not differ across groups. This was interpreted to mean that stutterers process auditory verbal information less efficiently, but not differently, than nonstutterers.