Jaime B. Lee

IMITATE: An intensive computer-based treatment for aphasia based on action observation and imitation

Background: Neurophysiological evidence from primates has demonstrated the presence of mirror neurons, with visual and motor properties, that discharge both when an action is performed and during observation of the same action. A similar system for observation–execution matching may also exist in humans. We postulate that behavioural stimulation of this parietal-frontal system may play an important role in motor learning for speech and thereby aid language recovery after stroke. Aims: The purpose of this article is to describe the development of IMITATE, a computer-assisted system for aphasia therapy based on action observation and imitation. We also describe briefly the randomised controlled clinical trial that is currently underway to evaluate its efficacy and mechanism of action. Methods & Procedures: IMITATE therapy consists of silent observation of audio-visually presented words and phrases spoken aloud by six different speakers, followed by a period during which the participant orally repeats the stimuli. We describe the rationale for the therapeutic features, stimulus selection, and delineation of treatment levels. The clinical trial is a randomised single blind controlled trial in which participants receive two pre-treatment baseline assessments, 6 weeks apart, followed by either IMITATE or a control therapy. Both treatments are provided intensively (90 minutes per day). Treatment is followed by a post-treatment assessment, and a 6-week follow-up assessment. Outcomes & Results: Thus far, five participants have completed IMITATE. We expect the results of the randomised controlled trial to be available by late 2010. Conclusions: IMITATE is a novel computer-assisted treatment for aphasia that is supported by theoretical rationales and previous human and primate data from neurobiology. The treatment is feasible, and preliminary behavioural data are emerging. However, the results will not be known until the clinical trial data are available to evaluate fully the efficacy of IMITATE and to inform theoretically about the mechanism of action and the role of a human mirror system in aphasia treatment.

Epidural cortical stimulation and aphasia therapy

Background: There are several methods of delivering cortical brain stimulation to modulate cortical excitability, and interest in their application as an adjuvant strategy in aphasia rehabilitation after stroke is growing. Epidural cortical stimulation, although more invasive than other methods, permits high-frequency stimulation of high spatial specificity to targeted neuronal populations. Aims: First we review evidence supporting the use of epidural cortical stimulation for upper limb recovery after focal cortical injury in both animal models and human stroke survivors. These data provide the empirical and theoretical platform underlying the use of epidural cortical stimulation in aphasia. Second, we summarise evidence for the application of epidural cortical stimulation in aphasia. We describe the procedures and primary outcomes of a safety and feasibility study (Cherney, Erickson, & Small, 2010), and provide previously unpublished data regarding secondary behavioural outcomes from that study. Main Contribution: In a controlled study comparing epidural cortical stimulation plus language treatment (CS/LT) to language treatment alone (LT), eight stroke survivors with nonfluent aphasia received intensive language therapy for 6 weeks. Four of these participants also underwent surgical implantation of an epidural stimulation device, which was activated only during therapy sessions. Behavioural data were collected before treatment, immediately after treatment, and at 6 and 12 weeks following the end of treatment. The effect size for the primary outcome measure, the Western Aphasia Battery Aphasia Quotient, was benchmarked as moderate from baseline to immediately post-treatment, and large from baseline to the 12-week follow-up. Similarly, effect sizes obtained at the 12-week follow-up for the Boston Naming Test, the Communicative Effectiveness Index, and for correct information units on a picture description task were greater than those obtained immediately post treatment. When effect sizes were compared for individual participant pairs on discourse measures of content and rate, effects were typically larger for the investigational participants receiving CS/LT than for the control participants receiving LT alone. These analyses support previous findings regarding therapeutic efficacy of CS/LT compared to LT, i.e., epidural stimulation of ipsilesional premotor cortex may augment behavioural speech-language therapy, with the largest effects after completion of therapy. Conclusions: Continued investigation of epidural cortical stimulation in combination with language training in post-stroke aphasia should proceed cautiously. Carefully planned studies that customize procedures to individual profiles are warranted. Information from research on non-invasive methods of CS/LT may also inform future studies of epidural cortical stimulation.

Impact of Personal Relevance on Acquisition and Generalization of Script Training for Aphasia: A Preliminary Analysis

PURPOSE The importance of personalization in script training in aphasia has been assumed but never tested. This study compared acquisition and generalization of personally relevant versus generic words or phrases appearing in the same scripts. METHOD Eight individuals (6 men; 2 women) with chronic aphasia received 3 weeks of intensive computer-based script training. For each participant, 2 scripts, a trained and an untrained generalization script, were embedded with 4 personally relevant word choices and 2-4 generic items that were similar across participants. Scripts were probed for accuracy at baseline and posttreatment. Significance testing was conducted on baseline and posttreatment scores, and for gains in personally relevant versus generic items. Effect sizes were computed. RESULTS Both personally relevant and generic items improved significantly on trained scripts. Improvements on untrained scripts were smaller, with only personally relevant items reaching significance. There was no significant difference on gains made on personalized versus generic items for trained scripts (p = .059), but the effect size was large (d = 0.90). For generalization scripts, this effect was small (d = 0.25) and nonsignificant. CONCLUSIONS Personally relevant words and phrases were acquired, although not generalized, more successfully than generic words and phrases. Data supports the importance of personalization in script training, but the degree of that importance requires further investigation.

Tau-U: A Quantitative Approach for Analysis of Single-Case Experimental Data in Aphasia

Purpose Tau-U is a quantitative approach for analyzing single-case experimental design (SCED) data. It combines nonoverlap between phases with intervention phase trend and can correct for a baseline trend (Parker, Vannest, & Davis, 2011). We demonstrate the utility of Tau-U by comparing it with the standardized mean difference approach (Busk & Serlin, 1992) that is widely reported within the aphasia SCED literature. Method Repeated writing measures from 3 participants with chronic aphasia who received computer-based writing treatment are analyzed visually and quantitatively using both Tau-U and the standardized mean difference approach. Results Visual analysis alone was insufficient for determining an effect between the intervention and writing improvement. The standardized mean difference yielded effect sizes ranging from 4.18 to 26.72 for trained items and 1.25 to 3.20 for untrained items. Tau-U yielded significant (p < .05) effect sizes for 2 of 3 participants for trained probes and 1 of 3 participants for untrained probes. A baseline trend correction was applied to data from 2 of 3 participants. Conclusions Tau-U has the unique advantage of allowing for the correction of an undesirable baseline trend. Although further study is needed, Tau-U shows promise as a quantitative approach to augment visual analysis of SCED data in aphasia.

Validity, reliability and sensitivity of the NORLA-6: Naming and oral reading for language in aphasia 6-point scale

Abstract Purpose: Evaluation of the Naming and Oral Reading for Language in Aphasia 6-point scale (NORLA-6), a scoring system of oral reading and naming performance in aphasia. Method: Data were drawn from 91 participants with non-fluent aphasia secondary to left-hemisphere stroke across four treatment studies. To assess validity, Spearman’s correlations were calculated between the NORLA-6 and the Gray Oral Reading Test-Fourth Edition (GORT-4) Accuracy score, GORT-4 Rate score and the Boston Naming Test (BNT). Inter-rater and test–retest reliability were evaluated using correlations. Sensitivity to change following oral reading intervention was analysed using Wilcoxon Signed Rank tests between pre- and post-treatment NORLA-6 scores. Result: NORLA-6 performance was significantly correlated (p < 0.001) with all reference tests (GORT-4 Accuracy, rs=0.84; GORT-4 Rate, rs= 0.61; and BNT, rs= 0.92). Inter-rater (ICC ≥0.90) and test–retest (r > 0.92) reliability were both excellent. Sensitivity following oral reading intervention was demonstrated in both oral reading accuracy and rate (p < 0.004). Conclusion: The NORLA-6 is a valid and reliable measure of oral reading and naming performance. It also demonstrates sensitivity to change in treatment-targeted behaviours. Therefore, the NORLA-6 scale may enhance outcome measurement in both clinical practice and aphasia research.

Attention in individuals with aphasia: Performance on the Conners’ Continuous Performance Test – 2nd edition

ABSTRACT Studies suggest that individuals with aphasia present with impairments in attention. However, most research has been conducted with small sample sizes using experimental protocols that lack established psychometric properties. We examined the attention performance of 114 individuals with chronic post-stroke aphasia using a standardised, norm-referenced assessment of attention, the Conners’ Continuous Performance Test-II (CPT-II; Conners, C. K. (2000). Conners’ Continuous Performance Test II. Toronto: Multi-Health Systems Inc). Participants completed the CPT-II and the Western Aphasia Battery-Revised (WAB-R; Kertesz, A. (2007). Western Aphasia Battery-Revised. San Antonio, TX: PsychCorp). As a group, variable performance on selected CPT-II measures was observed. Participants demonstrated impairments on omissions (48.2%) and hit reaction time (67.5%), with 11.4% demonstrating atypically slow performance and over half of the sample (56.1%) performing atypically fast. The Confidence Index, a summary score, was also within the impaired range for the majority of participants. However, there were also measures in which a greater percentage of participants demonstrated performance within normal limits. Using the WAB-R Aphasia Quotient (AQ) as a measure of severity, there was significantly worse performance in participants with more severe (AQ < 50) compared to less severe (AQ ≥ 50) aphasia. No significant differences in attention were identified between participants with fluent versus non-fluent aphasia. The CPT-II is a feasible measure for persons with aphasia, which may assist in identifying attention performance deficits that potentially affect language.

Attention Process Training-3 to improve reading comprehension in mild aphasia: A single-case experimental design study

ABSTRACT People with aphasia frequently present with nonlinguistic deficits, in addition to their compromised language abilities, which may contribute to their problems with reading comprehension. Treatment of attention, working memory and executive control may improve reading comprehension in individuals with aphasia, particularly those with mild reading problems. This single-case experimental design study evaluated the efficacy of Attention Process Training-3, an intervention combining direct attention training and metacognitive facilitation, for improving reading comprehension in individuals with mild aphasia. A multiple baseline design across six participants was used to evaluate treatment effects. The primary outcome measure was a maze reading task. Cognitive measures were administered pre- and post-treatment. Visual inspection of graphed maze reading performance data indicated a basic effect between APT-3 and improved maze reading for three of the six participants. Quantitative analyses, using Tau-U, corroborated findings identified through visual analysis. The overall effect size was significant (Tau = .48, p = .01). Results suggest that APT-3 has the potential to improve reading in individuals with aphasia, but that it may be more efficacious under certain conditions. Treatment and participant variables, including intensity of treatment and metacognitive strategy usage, are discussed as potential influences on participants’ responsiveness to APT-3.