Semantic feature analysis: incorporating typicality treatment and mediating strategy training to promote generalization.

PURPOSE: This investigation was designed to examine the generalization effects of semantic treatment for word retrieval deficits in people with aphasia. Semantic feature analysis (SFA; Boyle & Coelho, 1995), typicality treatment (Kiran & Thompson, 2003), and mediating strategy training were combined to maximize potential generalization effects. METHOD: Treatment, which included SFA and a semantic feature judgment task, was conducted with 9 participants with chronic aphasia in the context of multiple baseline designs across behaviors. Typical and atypical exemplars were trained across animate and inanimate categories. Treatment was sequentially modified to overtly train the use of SFA as a mediating strategy. RESULTS: Eight of the 9 participants demonstrated improvements in naming of trained stimuli. Positive generalization effects were limited overall; possible response generalization was evident for 5 participants. Instruction in the use of a mediating strategy resulted in improved naming of treated words for all participants; however, generalization to untreated words did not occur. CONCLUSION: Treatment using SFA resulted in improved naming of treated typical and atypical exemplars in both animate and inanimate categories for 8 of 9 participants. Training in a mediating strategy also resulted in improved retrieval of experimental words. Regardless of intervention approach, generalization to untreated items was limited.

Treatment for acquired apraxia of speech: examination of treatment intensity and practice schedule.

PURPOSE: The authors designed this investigation to extend the development of a treatment for acquired apraxia of speech (AOS)--sound production treatment (SPT)--by examining the effects of 2 treatment intensities and 2 schedules of practice. METHOD: The authors used a multiple baseline design across participants and behaviors with 4 speakers with chronic AOS and aphasia. Accuracy of production of trained and untrained words in phrases served as the dependent measure. Participants received 4 permutations of SPT (i.e., intensive-blocked, intensive-random, traditional-blocked, and traditional-random) applied sequentially to different lists of words. RESULTS: Positive changes in accuracy of articulation were observed for all participants for all phases of treatment. Two participants had a slightly poorer response to the traditional-random application of treatment. However, no clinically meaningful differences were noted among treatment applications when follow-up data were considered. CONCLUSIONS: Findings from this preliminary Phase II investigation suggest that similar outcomes may be achieved with SPT applied with different treatment intensities and different practice schedules. Extending treatment to achieve higher levels of accuracy may have improved maintenance effects, which may have revealed possible differences among conditions. In addition, overlap in methods used for random and blocked practice may have minimized distinctions between these conditions.

Apraxia of speech: perceptual analysis of trisyllabic word productions across repeated sampling occasions.

PURPOSE: Early apraxia of speech (AOS) research has characterized errors as being variable, resulting in a number of different error types being produced on repeated productions of the same stimuli. Conversely, recent research has uncovered greater consistency in errors, but there are limited data examining sound errors over time (more than one occasion). Furthermore, the influence of conditions of stimulus presentation (blocked vs. random) on sound errors remains uncertain. The purpose of this investigation was to examine the effects of repeated sampling and conditions of stimulus presentation on speech sound errors for 11 speakers with AOS/aphasia. METHOD: Trisyllabic words consisting of 7 target phonemes in the initial position served as stimuli. On 3 occasions, stimuli were elicited under 2 conditions: blocked (by phoneme) and randomized presentation. Speech productions were analyzed via narrow phonetic transcription. RESULTS: Findings revealed a similar overall mean percentage of errors in both conditions and across sampling occasions. Distortions were the dominant error type. CONCLUSION: There was no obvious pattern of responding across sampling occasions or conditions of stimulus presentation. The dominant error type differed among target phonemes, but there appeared to be some degree of consistency in the error types produced for the majority of target phonemes.

Acquired apraxia of speech: the effects of repeated practice and rate/rhythm control treatments on sound production accuracy.

PURPOSE: This investigation was designed to elucidate the effects of repeated practice treatment on sound production accuracy in individuals with apraxia of speech (AOS) and aphasia. A secondary purpose was to determine if the addition of rate/rhythm control to treatment provided further benefits beyond those achieved with repeated practice. METHOD: A single-subject design was employed with 10 speakers with chronic AOS and aphasia. Articulation accuracy served as the dependent measure. Participants received repeated practice treatment until a plateau in performance was observed or high levels of accuracy were achieved. If performance criterion was not reached, rate/rhythm control was added to the treatment to determine if additional gains would be made. RESULTS: For 8 of the participants, improvements were evident for all applications of repeated practice treatment, and positive response generalization was observed in most cases. When rate/rhythm control treatment was applied, modest additional gains were apparent for the majority of the applications. The 2 participants who did not benefit from repeated practice treatment also did not show improvements with rate/rhythm control treatment. CONCLUSIONS: Repeated practice treatment resulted in improved articulation for the majority of participants. The amount of improvement varied within and across participants. Rate/rhythm control appeared to have limited additional benefits for some participants.