JSLHR

Research Article

Combined Aphasia and Apraxia of Speech Treatment (CAAST): Effects of a Novel Therapy Julie L. Wambaugh,a,b Sandra Wright,a Christina Nessler,a and Shannon C. Mauszyckia,b

Purpose: This investigation was designed to examine the effects of a newly developed treatment for aphasia and acquired apraxia of speech (AOS). Combined Aphasia and Apraxia of Speech Treatment (CAAST) targets language and speech production simultaneously, with treatment techniques derived from Response Elaboration Training (Kearns, 1985) and Sound Production Treatment (Wambaugh, Kalinyak-Fliszar, West, & Doyle, 1998). The purpose of this study was to determine whether CAAST was associated with positive changes in verbal language and speech production with speakers with aphasia and AOS. Method: Four participants with chronic aphasia and AOS received CAAST applied sequentially to sets of pictures in

the context of multiple baseline designs. CAAST entailed elaboration of participant-initiated utterances, with sound production training applied as needed to the elaborated productions. The dependent variables were (a) production of correct information units (CIUs; Nicholas & Brookshire, 1993) in response to experimental picture stimuli, (b) percentage of consonants correct in sentence repetition, and (c) speech intelligibility. Results and Conclusions: CAAST was associated with increased CIU production in trained and untrained picture sets for all participants. Gains in sound production accuracy and speech intelligibility varied across participants; a modification of CAAST to provide additional speech production treatment may be desirable.

A

Robin, & Schmidt, 2009). It ranges in severity from a complete inability to speak to minor sound distortions. Stroke is the most common etiology for nonprogressive AOS (Duffy, 2013), and damage to cortical and/or subcortical areas of the language dominant hemisphere has been associated with AOS (Wambaugh & Shuster, 2008). Improvements in speech production have been demonstrated with a variety of AOS treatments (Wambaugh, Duffy, McNeil, Robin, & Rogers, 2006). Across the 59 AOS treatment investigations included in the AOS treatment guidelines systematic review, all 148 research participants had AOS accompanied by aphasia. However, none of the AOS treatments reviewed in the AOS guidelines included direct treatment for language (Wambaugh et al., 2006). Although it may be advantageous for researchers to develop and investigate treatments focused on a single disorder, a unilateral treatment focus may have limitations in terms of clinical application for persons with multiple disorders. Allocation of therapy time to different disorders and treatments may be challenging, particularly with a limited number of therapy sessions. Determining whether AOS or aphasia is the primary contributor to a particular communication disruption may be difficult, and perhaps

phasia and acquired apraxia of speech (AOS) are neurogenic disorders of language and motor speech, respectively. AOS seldom occurs as an isolated disorder and is typically accompanied by nonfluent aphasia (Duffy, 2013). The relative contributions of aphasia and AOS to overall communication disruption in persons with both disorders are not well understood; singly, and in combination, these disorders can significantly disrupt communication. Although many persons with aphasia and AOS likely require treatment for both disorders, there has been limited research addressing treatments that have been designed to target both. The purpose of the current investigation was to examine the effects of a newly developed behavioral treatment that targets aphasia and AOS simultaneously. AOS is characterized by slow rate of speech, difficulties in sound production, and disrupted prosody (McNeil,

a

Veterans Affairs Salt Lake City Health Care System, Utah University of Utah, Salt Lake City Correspondence to Julie L. Wambaugh: [email protected]

b

Editor: Rhea Paul Associate Editor: Kristine Lundgren Received January 7, 2014 Revision received May 1, 2014 Accepted June 20, 2014 DOI: 10.1044/2014_JSLHR-L-14-0004

Disclosure: The authors have declared that no competing interests existed at the time of publication.

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impossible, for a clinician to ascertain in a timely manner. For example, inability to describe a picture stimulus may result from a language disruption or a motor speech disruption, or a combination of both, in an individual with AOS and aphasia. Given the high co-occurrence of aphasia with AOS, the likelihood of the disorders interacting or co-contributing to communication disruption, and the need for efficient and clinically applicable treatments, a treatment that targets both disorders may be desirable. Response Elaboration Training (RET; Kearns, 1985) is an aphasia treatment that has been modified for use with persons with aphasia and AOS (Modified RET [M-RET]; Wambaugh & Martinez, 2000; Wambaugh, Wright, & Nessler, 2012). RET was developed to facilitate creative and generalizable language production by capitalizing on unique, patient-initiated utterances and has been shown to consistently result in increased production of content in discourse (Gaddie, Kearns, & Yedor, 1991; Kearns, 1985; Kearns & Scher, 1989; Kearns & Yedor, 1991; Yedor, Conlon, & Kearns, 1993). With RET, the clinician encourages the speaker to produce an utterance of his or her choice in response to picture stimuli. Reinforcement, modeling, and forward chaining are then used to expand the utterance. RET and M-RET have been shown repeatedly to result in improved production of language content in response to trained and untrained stimuli (see Wambaugh et al., 2012, for a review). Wambaugh and colleagues (Wambaugh & Martinez, 2000; Wambaugh et al., 2012) adapted the basic RET procedure to accommodate speech production difficulties associated with AOS. Although the modification included some techniques that may promote improved speech production (e.g., integral stimulation, repeated productions), M-RET does not include specific treatment for apraxic speech production errors, and speech production has not been a measured outcome. That is, increased language production remains the focus of M-RET. Because of the strong, experimentally sound evidence base supporting generalized language changes with RET and M-RET and the limited data concerning speech changes for other aphasia treatments, we chose to use M-RET as the foundation for a new treatment that targets both language and speech. We combined M-RET with an established AOS treatment, Sound Production Treatment (SPT; Wambaugh, 2004; Wambaugh, Kalinyak-Fliszar, West, & Doyle, 1998; Wambaugh & Mauszycki, 2010; Wambaugh & Nessler, 2004; Wambaugh, Nessler, Cameron, & Mauszycki, 2013; Wambaugh, Nessler, Wright, & Mauszycki, 2014). SPT is an articulatory-kinematic treatment for AOS that was designed to improve articulation of targeted sounds produced in the context of words, phrases, and/or sentences. SPT combines modeling, repetition, minimal pair contrast, integral stimulation, articulatory placement cueing, and feedback in a response-contingent hierarchy. SPT has been studied with AOS speakers of various severities with level of speech production during treatment being adjusted to meet the speaker’s needs (e.g., monosyllabic words, multisyllabic words, phrases). Although aspects of SPT and its

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application require further study (e.g., optimal presentation of stimuli, most effective dosage, and social validity), its acquisition, response generalization, and maintenance effects have been demonstrated to be robust and relatively predictable; improvement in production of treated sounds has been consistently observed in trained and untrained items during nontreatment probes. Increases in articulatory accuracy have been maintained above baseline levels for the majority of speakers in post-SPT follow-up probes. A key component of SPT in previous research has been the targeting of specific sounds that were determined to be problematic for the AOS speaker in pretreatment assessment. That is, treatment items have been selected on the basis of a priori observation of patterns of sound errors. In contrast, with M-RET, there are no predetermined target responses; treatment proceeds on the basis of speaker-initiated utterances. Therefore, with the new treatment, SPT could not be applied to preestablished target sounds. Instead, in the newly developed treatment, Combined Aphasia and Apraxia of Speech Treatment (CAAST), the SPT hierarchy is employed with the speaker-generated utterances that are unique with each treatment trial. As with RET and M-RET, a primary goal of CAAST is to increase verbal language productivity by facilitating elaboration of patient-initiated productions; flexible and generalized language use is expected (Kearns, 1985). In keeping with the emphasis of SPT, improved speech production is also a goal of CAAST. Given the dual focus of CAAST, language and speech production outcome measures were required to measure the effects of treatment. A measure of production of content in discourse was chosen to elucidate potential changes in language productivity (Nicholas & Brookshire, 1993). Because increases in content production have been regularly reported with RET and M-RET (Gaddie et al., 1991; Kearns, 1985; Kearns & Scher, 1989; Kearns & Yedor, 1991; Wambaugh & Martinez, 2000; Wambaugh et al., 2012; Yedor et al., 1993), it was deemed important that such changes be evident with CAAST. Typical SPT outcome measures, such as accuracy of targeted sounds/words in trained and untrained items, could not be utilized to evaluate the effects of CAAST because treatment does not involve prespecified targets. Consequently, a measure was devised in which percentage of consonants correct (PCC) was measured in the production of sentences. The sentences were developed to be similar to expected, participant-generated utterances in CAAST. In addition, single word intelligibility was selected as an outcome measure that could reflect positive changes in speech production. In summary, we have developed a new treatment that targets aphasia and AOS simultaneously. CAAST combines features of two existing treatments (i.e., M-RET and SPT) to increase generalizable verbal language skills and to improve speech production. Not only is this approach novel in terms of being a combined approach, it is also unique with respect to applying sound production remediation in

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the context of patient-initiated utterances. The specific experimental questions addressed in this investigation were as follows: 1.

2.

Is CAAST associated with increases in the production of content in discourse elicited in response to trained and untrained stimuli? Is CAAST associated with improvements in speech production as measured by PCC in sentences and single word speech intelligibility?

Participants Four men with chronic, stroke-induced aphasia and AOS served as participants. Participant characteristics are summarized in Table 1. Medical records indicated that each participant’s AOS and aphasia resulted from a single episode, left hemisphere stroke. The participants were native English speakers between 36 and 72 years of age. Each passed a pure tone hearing screening at 35 dB at 500, 1000, and 2000 Hz for at least one ear, unaided. All demonstrated performance within normal limits on the Test of Nonverbal Intelligence—4 (Brown, Sherbenou, & Johnsen, 2010). All had self-reported negative histories for alcohol or substance abuse and neurological conditions other than stroke; the reports were verified through review of existing medical records. None of the participants received any other speech/language therapy during the course of this study. Each participant lived in his own home with a significant other. The presence of AOS was determined using the diagnostic criteria described by McNeil, Robin, and Schmidt (1997, 2009). Speech samples were obtained from each participant employing the following elicitation tasks: Increasing Word Length and Repeated Trials subtests of the Apraxia Battery for Adults—Second Edition (Dabul, 2000);

2.

narrative and procedural discourse tasks (Nicholas & Brookshire, 1993);

Assessment of Intelligibility of Dysarthric Speech (AIDS; Yorkston & Beukelman, 1981);

4.

consonant production probe (Wambaugh, KalinyakFliszar, et al., 1998);

5.

sentence repetition (Wambaugh, West, & Doyle, 1998); and

6.

multisyllabic word repetition (Mauszycki & Wambaugh, 2008).

The following behaviors deemed necessary for the diagnosis of AOS were demonstrated by all of the participants: slow rate of speech production (including syllable segregation), sound errors that were relatively consistent in type and location across repeated trials, sound errors that were predominately sound distortions, and prosodic abnormalities. The presence of the requisite diagnostic characteristics and corresponding diagnosis of AOS was initially determined by each participant’s primary clinician (one of the authors) and was independently confirmed by the first author. All authors have extensive experience in the diagnosis, treatment, and study of AOS. The participants’ word-level intelligibility scores ranged from 8% to 76% as scored through orthographic transcription (Yorkston & Beukelman, 1981; see Table 2). Severity of AOS, estimated on the basis of intelligibility and prevalence of sound production errors, was considered to range from mild–moderate to moderate–severe across the participants. All of the participants presented with agrammatic aphasia. Participants 2, 3, and 4 received a diagnosis of Broca’s aphasia on the basis of the Western Aphasia Battery (Kertesz, 2007). Participant 1’s performance on the Western Aphasia Battery resulted in a classification of anomic aphasia. The participants’ productive verbal language ranged from single words to short sentences and was generally characterized as follows: Participant 1—short sentences and phrases; Participant 2—mainly single words; Participant 3—single words, phrases, and short sentences; and Participant 4—single words and phrases (for samples of discourse, see Appendix A in the online supplemental materials).

Method

1.

3.

Table 1. Participant characteristics.

Participant

Gender

Participant Participant Participant Participant

Male Male Male Male

1 2 3 4

CVA location/type

Age (years)

Months post onset of stroke

Years of education

Premorbid handiness

Race/ ethnicity

Hemiparesis

L MCA ischemic L MCA ischemic L MCA hemorrhagic L basal ganglia hemorrhagic with intraventricular hemorrhage and L frontal lobe hematoma

72 71 36 54

12 65 23 255

11+ 20 11 14

R R R R

White–nH / L White–nH / L White–nH / L White–nH / L

None R UE, R LE R UE, R LE R UE, R LE

Note. CVA = cerebrovascular accident; L = left; MCA = middle cerebral artery; R = right; nH / L = non-Hispanic/ Latino; UE = upper extremity; LE = lower extremity.

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Table 2. Pretreatment assessment results. Measure Western Aphasia Battery AQ Type Porch Index of Communicative Ability Overall percentile Verbal percentile Auditory percentile Reading percentile Test of Adolescent/Adult Word Finding Total raw score % comprehension Verb and Sentence Test Sentence construction Sentence anagram with pictures Sentence anagram without pictures Test of Nonverbal Intelligence—4 Percentile Reading Comprehension Battery for Aphasia Word-visual Word-auditory Word-semantic Functional reading Sentence-picture Assessment of Intelligibility of Dysarthric Speech (% single word) Estimated AOS severity

Participant 1

77.1 Anomic

Participant 2

24.3 Broca’s

Participant 3

Participant 4

56 Broca’s

55.6 Broca’s

58 59 54 40

47 17 43 84

49 51 40 28

49. 48. 64. 44.

55/107 95

0/107 93

44/107 93

8/107. 95.

6/20 9/20 12/20

0/20 10/20 16/20

0/20 8/20 8/20

4/20. 10/20. 6/20.

34th

42nd

19th

39th

10/10 10/10 9/10 8/10 9/19 76 Mild–moderate

10/10 10/10 10/10 8/10 10/10 8 Moderate–severe

9/10 6/10 9/10 DNT DNT 76 Moderate

7/10. 10/10. 9/10. 3/10. 8/10. 64. Moderate

Note. AQ = aphasia quotient; DNT = did not test; AOS = acquired apraxia of speech.

Overall percentile scores on the Porch Index of Communicative Ability (Porch, 2001) ranged from the 47th to 58th percentile. The participants did not exhibit symptoms of dysarthria as described by Duffy (2013).

Experimental Design General Description Each participant received treatment applied in the context of a multiple baseline design (MBD) across behaviors. Production of correct information units (CIUs; Nicholas & Brookshire, 1993) was measured repeatedly with three sets of experimental pictures in the baseline phase. Then, treatment was applied sequentially to two of the picture sets. Experimental control is demonstrated with the MBD across behaviors when systematic changes in the dependent variable coincide with application of treatment and when those effects are replicated with subsequent applications of treatment with that participant (Kratochwill et al., 2010). In the event that treatment results in generalized responding to untreated behaviors (i.e., changes in untreated behaviors occur prior to treatment being applied directly to those behaviors), demonstration of the replication of treatment effects within the participant may be difficult. We anticipated that increases in CIU production might occur with untreated experimental sets and included additional design controls. We completed additional probing prior to applying treatment to the second experimental set to ensure stability of responding with that set. Conceptually, this may be considered an additional baseline (“A”) phase designed to allow

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further treatment effects to be detected. In addition, A MBD across the participants’ component was included in the design in which the number of baseline measurements was extended across participants; the number of baseline probes was increased by one session across each participant so that baseline probes increased from five to eight for Participant 1 through Participant 4. To demonstrate experimental control, application of treatment must be systematically associated with behavioral change with treatment phases instituted at different time periods (relative to baseline) across participants. The design also included maintenance and follow-up measurements. Specifics of the design by each phase are provided in the following sections. Baseline Phase During baseline, discourse samples were elicited in response to the three sets of picture stimuli for each participant. Prior to the start of the study, the minimum number of baseline probes for the first participant was designated as five to allow application of the conservative dual-criterion (CDC) method (Fisher, Kelley, & Lomas, 2003) in data analysis. In addition, a nonascending or descending trend in CIU production was required to be evident in the baseline phase prior to initiation of treatment. Treatment Phase Following baseline, CAAST was applied sequentially to two experimental sets. During the treatment phases, the experimental set under treatment was probed after every two treatment sessions but immediately prior to the next

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treatment session. The sets that were not under treatment were probed less frequently throughout the treatment phases. The set slated for the second treatment phase was probed at the midpoint of the first treatment phase and then with increasing frequency as the first phase neared completion. Prior to initiation of treatment with the second set, additional extended baseline probing was conducted to ensure behavioral stability. The third set of pictures did not receive treatment and was probed only at the end of each phase of treatment. The reduced probing schedule was used to avoid overexposure and potential practice effects with untreated sets. All probes during the treatment phases were conducted prior to the day’s treatment session. Maintenance and Follow-Up Phases When treatment was applied to the second set of pictures, probes were completed with the previously treated set at the midpoint and end of the second treatment phase. Follow-up probes were completed with all experimental sets at 2 and 6 weeks following the last treatment session of the second treatment phase.

Procedures Experimental Stimuli Narrative discourse elicitation stimuli. Thirty line drawings depicting common actions were used as experimental stimuli. These pictures were part of a larger set of 100 drawings that were redrawn pictures from An Object and Action Naming Battery (Druks & Masterson, 2000). The 100 pictures had been validated for a previous investigation with respect to adequacy of depiction of the actions. Ten adults without brain damage ranging from 41 to 70 years of age (M age = 57.6 years; five men and five women) were asked to provide a one-word response that best described the action in each drawing; all drawings elicited the desired action name or an acceptable alternative. The drawings were not used in the current investigation to elicit specific action names but rather were used to stimulate production of narrative discourse. The drawings for Participants 1 and 2 were selected on the basis of personal relevance or potential interest as determined by each participant’s primary speech-language pathologist (SLP); approximately half of the items overlapped both participants’ sets. The drawings for Participants 3 and 4 were the same as those for Participant 2 to provide replications and counterbalancing with the stimuli. For each participant, the 30 pictures were randomly divided into three sets of 10 pictures each. Two lists were designated for use in treatment and measurement of acquisition effects in probes. The third list remained untreated to allow for assessment of generalization effects (for lists, see Appendix B in the online supplemental materials). Speech elicitation stimuli. Two sets of 10 short sentences were developed to elicit speech samples for measuring accuracy of articulation as reflected by PCC (see Appendix C in the online supplemental materials). The sentences were composed of words that were predicted to be

similar to those produced in the narrative discourse samples. These stimuli were developed on the basis of previous experience with M-RET and the expectation that use of the sentence frame in CAAST would stimulate production of at least canonical sentences. The same sentences were used for Participants 2, 3, and 4, and each sentence was seven to nine syllables in length (e.g., “The boy is riding a bike.”). Because of his less severe AOS and aphasia, more difficult sentences were devised for Participant 1 (Set 1 = 7–11 syllables; Set 2 = 10–19 syllables). Within each set, the10 sentences were presented verbally, one at a time in random order, and the participant was asked to repeat the sentence as accurately as possible. Printed stimuli were presented along with the verbal model for one of the sentence sets to counter possible word-retrieval or memory difficulties. Sentences in both sets (auditory only and auditory plus orthographic) were comparable for Participants 2, 3, and 4. For Participant 1, lengthier sentences were used for the auditory plus orthographic condition than in the auditory only condition. The longer sentences were developed because Participant 1’s speech production accuracy increased substantially with the addition of printed sentences. Probes Production of discourse was elicited in probes through presentation of the three picture sets. The order of presentation of sets and items within each set was randomized. The 10 pictures in each set were presented one at a time. The investigator provided the following instructions: “Tell me as much as you can about this picture. You can talk about this picture or anything it reminds you of.” No time limits were imposed. The preceding procedures were utilized with each picture presentation, and all probes were audio recorded. The 20 sentences used for eliciting speech samples were administered on three separate occasions prior to the start of treatment; for Participants 1, 2, and 4, these probes occurred prior to the final discourse probe. For Participant 3, these probes were administered after the final discourse probe. The sentences were then readministered at the midpoint and end of each treatment phase and at 2 and 6 weeks posttreatment.

Dependent Variable CIUs Total number of CIUs produced in response to the picture stimuli served as the primary dependent variable. CIUs reflect the appropriateness, relevancy, and informativeness of words produced by a speaker in relation to a particular topic (Nicholas & Brookshire, 1993). Procedures described by Nicholas and Brookshire (1993) for calculating CIUs were utilized. The discourse samples from the picture probes were orthographically transcribed using online transcriptions supplemented by the audio recordings. An investigator, who was blinded to the assignment of pictures to condition and was not involved in treatment, independently verified

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all transcriptions. Any discrepancies in transcription were corrected for calculation of CIUs. Total number of CIUs was tabulated separately for each set of 10 pictures for each probe. To measure the possible generalization effects of treatment beyond the experimental pictures used in this study, narrative and procedural discourse samples were collected prior to the start of treatment and following completion of all treatment using elicitation procedures established by Nicholas and Brookshire (1993). Nicholas and Brookshire included additional CIU metrics beyond total CIUs, such as percentage of CIUs and CIUs per minute. Wambaugh, Nessler, and Wright (2013) provided a rationale for utilizing number of CIUs rather than the other CIU metrics in the study of RET, which also applies to the examination of the effects of CAAST. PCC in Sentence Repetition For each target sentence, the number of consonants articulated correctly in content words was calculated. A scoring template was created for each sentence in which the target consonants were identified. Using the audio recordings, the examiner who conducted the PCC probe (one of the participant’s SLPs) scored each consonant as correct/ incorrect; examiners were not limited in the number of times that the audio recordings could be replayed. To be scored as correct, the consonant was required to be produced accurately in the correct location within the word. Words were not required to be in the correct order in the sentence. Omissions, substitutions, additions, and distortions were scored as incorrect. For an addition, total possible consonants correct was maintained, and a point was subtracted. If an entire word was omitted, all consonants for that word were scored as incorrect. PCC was calculated on the basis of total number of target consonants for the entire set of 10 sentences (for scoring examples, see Appendix C in the online supplemental materials). Word Intelligibility The single word intelligibility portion of the AIDS (Yorkston & Beukelman, 1981) was administered prior to and following treatment. An investigator who had not administered treatment to any of the participants and who was blinded to condition (pre- or posttreatment) used audio recordings to orthographically transcribe all AIDS samples. Percentage of intelligibility was calculated from the transcriptions.

Reliability Point-to-point reliability was calculated for scoring of CIUs in probes. For each participant, 20% of probes were quasi-randomly selected so that all phases of the study were represented. The reliability examiner independently scored the selected probes using the verified transcripts. Any items that were counted as CIUs by one examiner and not the other examiner were counted as disagreements. Total agreements and disagreements were tabulated for each

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probe (total judgments). The percentage of agreement of total judgments (total agreements divided by total judgments) was calculated for each probe for each participant: Participant 1—87.5%, Participant 2—85%, Participant 3—91.5%, and Participant 4—93%. Point-to-point reliability for scoring of PCC was also calculated for 20% of randomly selected sentence repetition probes. A reliability examiner used the audio recordings to rescore the selected sentence repetition probes. Average agreement for scoring of each consonant in each probe was 96.25% across the participants. Agreement across probes ranged from 88% to 100%. Point-to-point reliability for scoring CIUs in the nontreatment narrative and procedural discourse samples (Nicholas & Brookshire, 1993) was calculated for 50% of the samples. One of the pre- or posttreatment samples was randomly selected for each participant for rescoring by an examiner who had not conducted the original scoring. Average agreement was 86.5%, with a range from 82% to 91%.

Treatment CAAST combined steps from M-RET (Wambaugh & Martinez, 2000; Wambaugh et al., 2012) with SPT (Wambaugh et al., 1998). In addition, use of an empty sentence frame was included in the M-RET portion of treatment to assist in production elicitation and expansion. The therapist elicited a verbal production in response to an action picture and then used modeling, additional prompting, and forward-chaining to expand the initial utterance. The participant’s verbal responses were written in the empty frame by the therapist. After the expanded utterance was developed, the participant was asked to repeat the utterance. If there were articulatory errors in the repeated utterance, the SPT hierarchy was then implemented. Following completion of the SPT steps, the next picture was presented. The detailed CAAST protocol is provided in Appendix D in the online supplemental materials. A brief example of a treatment trial follows: Introduction: The therapist describes the sentence frame (completed one time at the start of the session). Step 1: Therapist—Presents action picture and says, “Tell me anything about this picture; what does it remind you of ?; what’s happening?” Participant—No response. Therapist—“You could say something like man spills . . . or . . . drops a cup.” Participant—“Spill.” Step 2: Therapist—“Spill, great.” Referring to the sentence frame, asks participant to indicate where to write “spill.” Step 3: Therapist—“What does the man spill?” Participant—“Milk.”

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Step 4: Therapist—“Milk, good, spill milk.” Referring to the sentence frame, asks the participant where to write “milk.” Step 5A: Therapist—“Repeat after me . . . spill milk.” Participant—“Pill milk.” Step 5B: Therapist—“Good try, but not quite correct. Let’s concentrate on this sound (underlines the “s” on the sentence frame) and try again . . . spill milk.” Participant—“Spill milk.” Therapist—“That’s right. Now, let’s say it three more times.” Step 6: Therapist—Removes the picture and imposes a 5-s delay (e.g., “Wait and then I’m going to ask you to say it again”). Participant—“Milk.” Therapist—“Good try, but not quite. Watch me and try it with me . . . spill milk.” Each of the 10 treatment pictures (i.e., pictures in an experimental set) was submitted to the CAAST treatment hierarchy, one at a time in random order in each treatment session. All six steps of the treatment hierarchy were completed with each picture. After presentation of the 10 pictures, the expanded productions were submitted to the SPT step/substeps (Step 5) one more time if time permitted. As shown in the full treatment protocol, CAAST provides variations in the substeps depending on the participant’s responses. Examples of elaborated responses produced during CAAST are shown in Appendix E in the online supplemental materials. Participants were scheduled for treatment three times per week and were seen in their homes, a clinic setting, or a social rehabilitation day program according to their preference: Participant 1—home, Participant 2—home and clinic, Participant 3—home, and Participant 4—home and social rehabilitation day program. The conditions were as quiet and free of distractions as possible. For all participants, there was a comfortable seating arrangement with table space for picture presentation. If a family member chose to observe a session (a rare occurrence), he or she sat out of the participant’s line of sight and was asked to not make comments to the participant. Treatment sessions (excluding probes) ranged from approximately 60 to 75 min. Treatment was administered by SLPs who were certified by the American Speech-Language-Hearing Association or by a doctoral student completing a clinical fellowship year (supervised by a certified SLP at least 25% of the time). Each participant was assigned two SLPs (including the clinical fellow) who shared treatment and testing responsibilities. As noted previously, each participant received treatment applied sequentially to two sets of experimental pictures. Order of administration of the sets was counterbalanced across participants. Treatment length was established prior

to the start of the study, with 20 treatment sessions designated per treatment phase (i.e., per experimental set); this number of sessions was selected on the basis of previous experience with M-RET (Wambaugh & Martinez, 2000; Wambaugh et al., 2012) as a best estimate for elucidating treatment effects. However, as treatment and probing progressed with Participant 1, treatment effects appeared to have stabilized after 14 treatment sessions with the first experimental set; consequently, treatment was terminated with the first set and was extended to the second set of pictures for 14 sessions. For Participants 2, 3, and 4, 20 sessions were completed for each treatment phase. All SLPs (and the clinical fellow) practiced administration of CAAST prior to use with participants. A treatment administration log was created to ensure that all steps of the CAAST protocol were employed accurately (see Appendix F in the online supplemental materials). The log contained therapist instructions for each of the six CAAST treatment steps and substeps along with a grid to mark completion of each step. A log was used for every treatment session, and all sessions were audio recorded. Ten percent of all treatment sessions were quasirandomly selected (balanced across SLPs) for calculation of accuracy of administration of treatment. An examiner who had not administered the selected treatment session used the audio recordings to determine accuracy of administration of each step of the treatment protocol. The number of times a treatment component was correctly administered was determined and divided by the number of opportunities for occurrences of that component. Accuracy for administration of the following CAAST components was as follows: 1.

presentation of treatment pictures (10 per session)— 100%;

2.

accurate elicitation and reinforcement for Steps 1–6 (60 per session)—98%; and

3.

accurate elicitation of elaborated production repetitions (30 per session)—98%.

Results Production of CIUs With Experimental Picture Sets Data representing number of CIUs produced during probes are shown in Figures 1–4 for Participants 1–4, respectively. Within each figure, the separate graphs represent production of CIUs in response to presentation of a particular picture set (two treated sets and one untreated set). The order of the graphs from top to bottom in each figure indicates the order of application of treatment to the sets. Graphed data for the picture sets reflect total number of CIUs produced for all 10 pictures in the set. The scaling of the y-axes varies by participant to accommodate the range of number of CIU productions across participants. Determining that a systematic change in behavior was associated with treatment requires evaluation of the

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Figure 1. Number of correct information units (CIUs) produced in response to experimental picture sets by Participant 1.

level, trend, and variability of probe data within and across treatment phases. In addition, the immediacy of change, the consistency of performance, and the degree of overlap across phases must also be considered (Kratochwill et al., 2010). The CDC method (Fisher et al., 2003) was used to aid in interpretation of treatment effects. The CDC method

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entailed creating trend and mean (level) lines based on each set of baseline data. These lines were then adjusted upward by 0.25 SDs (standard deviation of each set of baseline data) in the direction of the expected treatment effect. The adjusted trend and level lines were then extended into each corresponding treatment phase (for details of implementation

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Figure 2. Number of CIUs produced in response to experimental picture sets for Participant 2.

of the CDC method, see Fisher et al., 2003; Swoboda, Kratochwill, & Levin, 2010). In Figures 1–4, the level line is represented by long dashed lines, and the trend line is represented by short dashed lines. With the CDC method, interpretation of positive treatment effects relies on a

prespecified number of data points falling above both lines; the prespecified number of points is dependent on the number of total probe points in the treatment phase (i.e., 8 data points in a 9- to 10-point treatment phase; 6 data points in a 6- to 7-point treatment phase; Fisher et al., 2003). Type I

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Figure 3. Number of CIUs produced in response to experimental picture sets for Participant 3.

error rates (i.e., erroneous attribution of a positive treatment effect) have been shown to be well controlled with the CDC method even with high degrees of autocorrelation (Fisher et al., 2003). In addition, the CDC method has been found to have higher power than the general linear model and interrupted time series analysis. Effect sizes (d-index; Bloom, Fischer, & Orme, 2009; Cohen, 1988) were calculated as indicators of the magnitude of change associated with treatment; d-index values are shown on the individual graphs in Figures 1–4 and in

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Appendix G in the online supplemental materials. For the calculation of effect sizes, the initial baseline probe values for a given set (i.e., probes conducted in baseline prior to the application of any treatment) and the two follow-up probe values for that set were used. The calculated effect sizes reflect the cumulative effects of both phases of treatment on the behavior (i.e., any generalization effects would be included). To interpret the effect sizes, the following benchmarks suggested by Beeson and Robey (2006) were used:

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Figure 4. Number of CIUs produced in response to experimental picture sets for Participant 4.

d = 2.6, small; d = 3.9, medium; and d = 5.8, large. These values were derived from effect sizes calculated by Robey, Schultz, Crawford, and Sinner (1999) as part of a review of single-subject design treatment investigations in aphasia that included a predominance of studies focused on verbal production. Consequently, the proposed benchmarks may

have utility for interpreting the magnitude of the effect sizes obtained for CAAST. Participant 1. As shown in Figure 1, Participant 1 received CAAST applied first to Set 1 and then to Set 3, with Set 2 remaining untreated. Baseline probe values ranged from 28 to 58 CIUs across the three sets. Following

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application of CAAST to Set 1, CIU production for that set increased to a maximum of 173 CIUs (highest baseline value for Set 1 was 47 CIUs). Upon the completion of treatment with Set 1, increases in CIU production were observed for the untrained sets: Set 2—90 CIUs, and Set 3—103 CIUs. Because of the increases in CIU production with Set 3, which was slated for the second treatment application, extended probing was completed to establish behavioral stability prior to treatment application. With six additional probes (Probe Sessions 13–18), performance with Set 3 remained somewhat variable, but it appeared to have reached a ceiling of approximately 140 CIUs. When treatment was applied to Set 3, additional gains were seen, with an increase to a maximum of 174 CIUs; however, performance remained variable. Participant 1 completed 14 treatment sessions with Set 3 but was unable to complete a final probe because of family issues (i.e., deaths in the family). Followup probes at 2 and 6 weeks posttreatment revealed that gains in CIU production were maintained well above initial baseline levels for both treated sets and the untreated set: At 6 weeks posttreatment, Set 1 = 114 CIUs, Set 3 = 135 CIUs, and Set 2 = 75 CIUs. As shown in the top graph of Figure 1, all of the Set 1 probes during the treatment phase fell above both CDC lines, indicating a systematic behavior change associated with treatment. Because of the observed generalization with Set 3, the CDC lines were drawn using the extended probed data following completion of treatment with Set 1 (i.e., second “A” phase). As can be seen in the second graph of Figure 1, only three of the six Set 3 data points in the second treatment phase fell above both CDC lines, suggesting a lack of treatment effect for this phase. Large effect sizes were obtained for the two treated sets (d = 8.89, Set 1; d = 6.9, Set 3), and a medium effect size was obtained for the untreated set (d = 4.12, Set 2). As noted previously, the effect sizes represented the magnitude of change from the initial baseline probes. Participant 2. Participant 2 received treatment applied first to Set 3 and then to Set 1 (see Figure 2). Over the six initial baseline sessions, number of CIUs ranged from 3 to 23 across sets. Following application of CAAST to Set 3, increases in CIU production were observed for that set, with a maximum of 53 CIUs. For untrained sets, CIU production increased above baseline levels for Set 1 but not for Set 2. Extended probing was completed with Set 1 prior to treatment of that set. The additional probing indicated stable responding ranging between 37 and 42 CIUs in the five probe sessions preceding application of CAAST with Set 1. With application of treatment, CIU production for Set 1 increased to a maximum of 58 CIUs. Substantial increases in CIU production were also seen for the remaining untreated set (Set 2), with 45 CIUs produced at the end of treatment of Set 1. For all sets, number of CIUs remained well above initial baseline levels at 2 and 6 weeks posttreatment: At 6 weeks posttreatment, Set 3 = 37 CIUs, Set 1 = 43 CIUs, and Set 2 = 40 CIUs. As can be seen in Figure 2, all of the probe data points in the first treatment phase fell above both CDC lines, and

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8 of 10 of the probe data points in the second treatment phase fell above both lines. Thus, the CDC criteria were met for both treatment phases, indicating that treatment was associated with systematic behavioral change. A medium effect size of d = 5.41 was obtained for the first treated set, and a large effect size of d = 6.11 was obtained for the second treated set. A small effect size of 3.8 was found for the untreated set. Participant 3. As shown in Figure 3, Participant 3 received CAAST applied first to Set 1 followed by treatment of Set 3. Across the seven initial baseline sessions, CIU production across sets ranged from 21 to 53. With application of treatment, a maximum of 106 CIUs was produced with Set 1. Increases in CIU production were also seen for the untreated sets at the end of the first phase of treatment. Participant 3 experienced a hospitalization following the first treatment phase (nonneurological in nature), and a 1-month gap in probing occurred. Additional extended probing was conducted after he returned home to ensure stability of responding with Set 3 (the set designated for second treatment phase). With application of treatment to Set 3, CIU production initially decreased but then increased above the extended probing levels with increases being unstable. Follow-up probing revealed high, stable levels of CIU production for both treated sets: Set 1 = 165 and 144 CIUs at 2 and 6 weeks, respectively, and Set 3 = 190 CIUs at both 2 and 6 weeks posttreatment. Gains in production of CIUs for the untreated set also remained at high levels posttreatment (Set 2 = 250 and 152 CIUs at 2 and 6 weeks posttreatment, respectively). The CDC criteria for demonstration of a treatment effect were met for the first treatment phase (10 of 10 points above both lines) but not the second treatment phase (3 of 10 data points above both lines; see Figure 3). Large effect sizes of d = 15.52 and d = 21.63 were found for Sets 1 and 3, respectively (both treated sets). A medium effect size of d = 5.72 was obtained for the untreated set. Participant 4. Participant 4 received CAAST applied sequentially to Sets 2 and 3 (see Figure 4). CIU production ranged from 6 to 20 CIUs across sets over the eight initial baseline sessions. When treatment was applied to Set 2, CIU production increased to a high of 48 CIUs for that set (baseline high of 15 CIUs). Treatment of Set 2 was also associated with increases in CIU production for the untrained sets, with increases to 26 CIUs and 28 CIUs for Sets 3 and 1, respectively. Extended probing with Set 3 prior to application of CAAST indicated stable performance ranging from 19 to 26 CIUs. With application of CAAST to Set 3, increases to a high of 53 CIUs were seen. Upon completion of treatment with Set 3, additional increases were seen with untreated Set 1. Follow-up probing indicated that gains were maintained with all sets at levels well above baseline: At 6 weeks posttreatment, Set 2 = 50 CIUs, Set 3 = 56 CIUs, and Set 1 = 55 CIUs. For both treatment phases, 9 of 10 treatment phase probe data points fell above both CDC lines, indicating a systematic change in CIU production associated with treatment. Large effect sizes were obtained for both treated sets:

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Set 2, d = 13.64; and Set 3, d = 16.01. A medium effect size was found for the untreated set (Set 1), with d = 5.79.

Production of CIUs in Pre- and Posttreatment Discourse Samples Increased CIU production in narrative and procedural discourse (Nicholas & Brookshire, 1993) was seen for Participants 2 and 3 at posttreatment: Participant 2, 12 CIUs (pre) and 22 CIUs (post); Participant 3, 129 CIUs (pre) and 260 CIUs (post). Participants 1 and 4 demonstrated decreases in CIU production in posttreatment narrative and procedural discourse: Participant 1, 279 CIUs (pre) and 104 (post); Participant 4, 54 CIUs (pre) and 36 CIUs (post) (see Appendix H in the online supplemental materials).

PCC in Sentence Repetition PCC values for pretreatment, interim, and posttreatment sentence repetition samples are shown in Table 3. Values are presented separately for the sets of sentences, and the sets are designated as being presented “with” or “without” printed stimuli. Participant 1 demonstrated relatively high levels of accuracy in the three pretreatment baseline samples, with PCC ranging from 82% to 90% across the samples. After treatment was initiated, there were only two instances when PCC was slightly higher than baseline levels. Participant 2 displayed low levels of accuracy in baseline samples, with PCC ranging between 7% and 17% for the auditory only sentences (“without”) and between 12% and 24% for the auditory plus orthographic sentences (“with”). After the first phase of treatment, PCC increased to 24% for the auditory only sentences, but this increase was not sustained; PCC at follow-up periods approximated baseline levels for the auditory only condition. For the auditory plus orthographic sentences, increased PCC values were obtained at all sampling times following the initiation of treatment. However, accuracy levels for follow-up probes were only slightly higher than the highest baseline level (e.g., 26%). Participant 3’s PCC values ranged from 35% to 44% for the auditory only sentences and from 39% to 51% for the auditory plus orthographic condition in baseline. Although PCC values exceeded baseline for most sampling times for the auditory only sentences after treatment began, the 6-week follow-up PCC value approached baseline levels (e.g., 46%). Increases were also observed for the auditory plus orthographic sentences, and these gains were maintained in follow-up samples (68% at 6 weeks posttreatment). In baseline samples, Participant 4’s auditory only sentence PCC values ranged from 34% to 44%. Baseline PCC values for auditory plus orthographic sentences ranged from 33% to 55%. Increases that were maintained at follow-up were seen for both sets of sentences: At 6 weeks posttreatment, auditory only PCC = 60%, and auditory plus orthographic PCC = 78%.

Single Word Intelligibility Pre- and posttreatment single word intelligibility scores from the AIDS (Yorkston & Beukelman, 1981) are shown in Appendix H in the online supplemental materials. A 12% increase in intelligibility was seen for Participant 3, but scores remained relatively unchanged for the other participants.

Discussion This study was conducted to determine whether CAAST was associated with improvements in verbal language and speech production in speakers with chronic aphasia and AOS. Increases in production of content were found for all participants, whereas gains in speech production measures varied across participants. The outcome measure chosen to measure language production changes was number of CIUs produced in discourse; this measure was selected to allow comparison of the effects of CAAST with RET (Kearns, 1985) and M-RET (Wambaugh & Martinez, 2000; Wambaugh et al., 2012). Substantial increases in production of CIUs in response to trained picture sets were found for all participants in the current study. These increases were consistent with previous RET findings (Kearns, 1985; Kearns & Scher, 1989; Kearns & Yedor, 1991) and M-RET findings (Wambaugh & Martinez, 2000; Wambaugh et al., 2012). Benchmarks for effect sizes are not currently available specifically for RET and M-RET. However, effect sizes at follow-up for treated sets for the current participants (d-index = 5.41–21.63) were in keeping with those found for M-RET (Wambaugh et al., 2012; d-index = 0.58–19.45). Generalization to untreated picture sets was consistently positive in the present study. Although generalization to untreated sets has been found to occur for the majority of participants who have received RET or M-RET, generalization has been found to be absent or limited in a few instances (see Wambaugh et al., 2012, for a summary). Small effect sizes ranging from 3.8 to 5.79 were obtained for the untrained set for the four participants who received CAAST. In comparison, less than small effect sizes were found for untrained sets for four of six participants who received M-RET (Wambaugh et al., 2012). The finding that changes in CIU production for untreated picture sets was positive but consistently of lesser magnitude than treated sets is consistent with Yedor et al.’s (1993) review of generalization findings with RET; across RET participants, increases in untrained items were about 33% of increases with trained items. Generalization of treatment effects to the narrative and procedural discourse samples elicited using Nicholas and Brookshire’s (1993) procedure was positive for two of the four participants. This finding is in line with M-RET findings in that Wambaugh et al. (2012) found posttreatment increases in this condition for four of six participants. However for the remaining two participants, decreases in CIU production were found posttreatment. Repeated

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Table 3. Percentage of consonants correct in sentence repetition. Participant

Condition

BL 1

BL 2

BL 3

Midtreatment 1

Posttreatment 1

Midtreatment 2

Posttreatment 2

2 weeks

6 weeks

Participant 1

Without printed stimuli With printed stimuli Without printed stimuli With printed stimuli Without printed stimuli With printed stimuli Without printed stimuli With printed stimuli

87 89 9 20 35 39 44 33

86 90 17 24 39 51 34 55

82 87 7 12 44 48 43 47

82 91 15 33 58 55 56 79

87 86 24 27 40 54 50 69

88 90 13 30 47 69 74 76

CNT CNT 18 26 61 68 76 81

82 93 14 26 51 60 59 80

83 89 15 26 46 68 60 78

Participant 2 Participant 3 Participant 4

Note. Bold values are greater than the highest baseline (BL) value. CNT = could not test because participant was unavailable.

measurement with these stimuli prior to treatment would be desirable in future investigations to elucidate withinparticipant variability with this measure (Cameron, Wambaugh, & Mauszycki, 2010). Without such information, gains or losses associated with treatment cannot be reliably determined. Differences in participant characteristics, treatment variations, and study designs may account for slight differences in CIU production findings across the various RET and M-RET reports and this investigation of CAAST. However, it appears that CAAST outcomes relative to CIU production were quite similar to those of RET and M-RET. An anonymous reviewer suggested that the increases in CIU production with untrained sets may have occurred because the sentences used in the PCC probes served as models for responding. This did not appear to be the case, as PCC probes were completed prior to the final baseline picture description probe for Participants 1, 2, and 4; consequently, any benefit from these sentences should have been apparent during baseline. For Participant 3, all PCC probes were completed after the final picture description probe. However, there were no gains in CIU production in the first two picture description probes following treatment application (after the PCC probes), which speaks against any effect from the PCC sentences. It was also suggested that use of the CAAST sentence frame may have caused the participants to adjust their responding in the picture probes. We argue that flexibility in responding is a goal of CAAST (and of RET), and if a different approach to narrative discourse occurred with treatment, this is compatible with a treatment effect (note that no sentence frames are used with RET). Speech production outcomes were not as robust as the CIU outcomes for CAAST. With respect to accuracy of consonant production in repeated sentences, clear improvements were seen with auditory only (without written stimuli) and auditory + orthographic (with written stimuli) sentences for two participants (Participant 3 and Participant 4). A third participant demonstrated gains in repetition that were not maintained (Participant 2), and the fourth participant (Participant 1) did not exhibit any notable increases. An improvement in single word speech intelligibility was found for only one of the participants (Participant 3). CAAST includes components of the apraxia treatment, SPT. As noted previously, SPT has typically been applied to prespecified target items (e.g., specific sounds in words or specific words with multiple sound targets). Consequently, SPT effects have been measured in terms of improvement of targeted items (Wambaugh, 2004; Wambaugh & Mauszycki, 2010; Wambaugh & Nessler, 2004; Wambaugh, Nessler, Cameron, & Mauszycki, 2013). With CAAST, the participant generates novel utterances, and, as such, there are no prespecified targets for treatment. Therefore, direct comparison of findings from the current study with previous SPT findings is not possible. We had been concerned that there might not be sufficient opportunities for instruction and practice with erroneous productions with CAAST. That is, repeated practice with productions that are frequently in

error is an important component of SPT; CAAST offered fewer opportunities for practice than is typical with SPT. This may be the reason why improvements in speech production were not found with all participants. However, it is unknown as to whether SPT would result in improvements in the speech production outcome measures chosen for this study. That is, on the basis of our measures, we cannot state that the effects of CAAST on speech production differed from SPT. The speech outcome measures for CAAST may or may not have reflected the practice that occurred during CAAST; an analysis of all of the productions and sound errors that occurred during treatment is beyond the scope of this initial report. PCC in repetition of sentences (which were predicted to be similar to those generated during CAAST) was chosen as a general measure of speech production accuracy. For the participants who did not demonstrate change on this measure (Participant 1 and Participant 2), there may have been issues with stimuli difficulty that contributed to the lack of findings. Specifically, Participant 1 made relatively few errors on the sentences prior to treatment, leaving little room for improvement. Conversely, Participant 2 displayed a great deal of difficulty in repeating sentences of seven to nine syllables. Although the PCC measure was focused on speech production, the participants’ aphasia certainly played a role in ability to repeat accurately. Shorter sentences or phrases would likely have been more appropriate for Participant 2 and may have allowed improvements in PCC to be evident. Interpretation of the clinical significance of changes in PCC requires further study. On the other hand, stimuli length may have not played a role in the outcomes. The second speech production outcome measure, single word speech intelligibility, was clearly not impacted by the factor of length. However, this measure could also have been affected by the participants’ aphasia. It would have been preferable if we had conducted repeated administrations of the AIDS (Yorkston & Beukelman, 1981) to establish individual patterns of variability for the participants’ intelligibility scores. However, the most parsimonious explanation for the nonrobust speech production outcomes is that insufficient AOS treatment occurred. Future development of CAAST will include additional SPT trials with the participants’ self-generated utterances. In addition to modifying the current outcome measures in terms of difficulty (sentence repetition) and repeated administrations (intelligibility), other speech outcome measures will be explored. For example, intelligibility of self-generated utterances may be an appropriate outcome measure for CAAST. Additional language outcome measures will also be evaluated with CAAST. Analyses of language changes associated with RET and M-RET (beyond amount of content) have revealed qualitative improvements (e.g., increases in novel content, increases in mean length of utterance, and increases in phrase and sentence production) for some participants. Given the increases in CIUs found with CAAST and the overlap of treatment techniques with RET and M-RET, similar qualitative changes would be expected with CAAST.

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Design issues relative to the generalization effects found with CAAST also warrant attention in future investigations. That is, generalization to untrained behaviors may result in difficulty in demonstrating experimental control through replication of treatment effects. In the current investigation, we were able to reestablish stable (albeit higher) extended baselines with untreated behaviors prior to applying the second phase of treatment. For two participants (Participant 2 and Participant 4), treatment effects with the second treated behavior were clearly demonstrated (according to CDC criteria). For Participant 1 and Participant 3, although behavioral change appeared to occur with the second treatment application, changes did not meet CDC criteria, which reduced the experimental control afforded by the MBD-behaviors design. Because generalization was anticipated, we included the MBD-participants design to provide additional experimental control. With baselines extended across participants, behavioral change did not occur until treatment was implemented in all cases. However, the increase of one additional probe per participant is acknowledged as being minimal. In future investigations, it would be preferable to implement the MBD-participants design using more rigorous extensions of baselines across participants (e.g., increases of 2–3 probe sessions per participant). As in the development of any new treatment, there are many aspects of CAAST that require investigation. On the basis of the current findings, it appears that combining treatment techniques from RET (and M-RET) with those of SPT did not adversely affect outcomes in terms of CIU production. Although not all participants demonstrated improvements in speech production, it appears that CAAST may also have speech production benefits for some participants. However, additional speech production practice/ training may be necessary to effect consistent positive changes in speech outcome measures.

Acknowledgments This research was supported by the Department of Veterans Affairs, Rehabilitation Research and Development. Thanks are extended to Catharine DeLong for her assistance with this project.

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