The Aphasia Communication Outcome Measure: Motivation, Development, Validity Evidence, and Interpretation of Change Scores.

The Aphasia Communication Outcome Measure (ACOM) is a patient-reported measure of communicative functioning developed for persons with stroke-induced aphasia. It was motivated by the desire to include the perspective of persons with aphasia in the measurement of treatment outcomes and to apply newly accessible psychometric tools to improve the quality and usefulness of available outcome measures for aphasia. The ACOM was developed within an item response theory framework, and the validity of the score estimates it provides is supported by evidence based on its content, internal structure, relationships with other variables, stability over time, and responsiveness to treatment. This article summarizes the background and motivation for the ACOM, the steps in its initial development, evidence supporting its validity as a measure of patient-reported communication functioning, and current recommendations for interpreting change scores.

Exposing the Backstage: Critical Reflections on a Longitudinal Qualitative Study of Residents' Care Networks in Assisted Living.

In this article, we analyze the research experiences associated with a longitudinal qualitative study of residents' care networks in assisted living. Using data from researcher meetings, field notes, and memos, we critically examine our design and decision making and accompanying methodological implications. We focus on one complete wave of data collection involving 28 residents and 114 care network members in four diverse settings followed for 2 years. We identify study features that make our research innovative, but that also represent significant challenges. They include the focus and topic; settings and participants; scope and design complexity; nature, modes, frequency, and duration of data collection; and analytic approach. Each feature has methodological implications, including benefits and challenges pertaining to recruitment, retention, data collection, quality, and management, research team work, researcher roles, ethics, and dissemination. Our analysis demonstrates the value of our approach and of reflecting on and sharing methodological processes for cumulative knowledge building.

A Flexible and Integrated System for the Remote Acquisition of Neuropsychological Data in Stroke Research.

BACKGROUND: Neuropsychological testing is a central aspect of stroke research because it provides critical information about the cognitive-behavioral status of stroke survivors, as well as the diagnosis and treatment of stroke-related disorders. Standard neuropsychological methods rely upon face-to-face interactions between a patient and researcher, which creates geographic and logistical barriers that impede research progress and treatment advances. INTRODUCTION: To overcome these barriers, we created a flexible and integrated system for the remote acquisition of neuropsychological data (RAND). The system we developed has a secure architecture that permits collaborative videoconferencing. The system supports shared audiovisual feeds that can provide continuous virtual interaction between a participant and researcher throughout a testing session. Shared presentation and computing controls can be used to deliver auditory and visual test items adapted from standard face-to-face materials or execute computer-based assessments. Spoken and manual responses can be acquired, and the components of the session can be recorded for offline data analysis. MATERIALS AND METHODS: To evaluate its feasibility, our RAND system was used to administer a speech-language test battery to 16 stroke survivors with a variety of communication, sensory, and motor impairments. The sessions were initiated virtually without prior face-to-face instruction in the RAND technology or test battery. RESULTS: Neuropsychological data were successfully acquired from all participants, including those with limited technology experience, and those with a communication, sensory, or motor impairment. Furthermore, participants indicated a high level of satisfaction with the RAND system and the remote assessment that it permits. CONCLUSIONS: The results indicate the feasibility of using the RAND system for virtual home-based neuropsychological assessment without prior face-to-face contact between a participant and researcher. Because our RAND system architecture uses off-the-shelf technology and software, it can be duplicated without specialized expertise or equipment. In sum, our RAND system offers a readily available and promising alternative to face-to-face neuropsychological assessment in stroke research.

Self- and surrogate-reported communication functioning in aphasia.

PURPOSE: To evaluate the dimensionality and measurement invariance of the aphasia communication outcome measure (ACOM), a self- and surrogate-reported measure of communicative functioning in aphasia. METHODS: Responses to a large pool of items describing communication activities were collected from 133 community-dwelling persons with aphasia of ≥ 1 month post-onset and their associated surrogate respondents. These responses were evaluated using confirmatory and exploratory factor analysis. Chi-square difference tests of nested factor models were used to evaluate patient-surrogate measurement invariance and the equality of factor score means and variances. Association and agreement between self- and surrogate reports were examined using correlation and scatterplots of pairwise patient-surrogate differences. RESULTS: Three single-factor scales (Talking, Comprehension, and Writing) approximating patient-surrogate measurement invariance were identified. The variance of patient-reported scores on the Talking and Writing scales was higher than surrogate-reported variances on these scales. Correlations between self- and surrogate reports were moderate-to-strong, but there were significant disagreements in a substantial number of individual cases. CONCLUSIONS: Despite minimal bias and relatively strong association, surrogate reports of communicative functioning in aphasia are not reliable substitutes for self-reports by persons with aphasia. Furthermore, although measurement invariance is necessary for direct comparison of self- and surrogate reports, the costs of obtaining invariance in terms of scale reliability and content validity may be substantial. Development of non-invariant self- and surrogate report scales may be preferable for some applications.

Effects of Semantic Feature Type, Diversity, and Quantity on Semantic Feature Analysis Treatment Outcomes in Aphasia.

Purpose Semantic feature analysis (SFA) is a naming treatment found to improve naming performance for both treated and semantically related untreated words in aphasia. A crucial treatment component is the requirement that patients generate semantic features of treated items. This article examined the role feature generation plays in treatment response to SFA in several ways: It attempted to replicate preliminary findings from Gravier et al. (2018), which found feature generation predicted treatment-related gains for both trained and untrained words. It examined whether feature diversity or the number of features generated in specific categories differentially affected SFA treatment outcomes. Method SFA was administered to 44 participants with chronic aphasia daily for 4 weeks. Treatment was administered to multiple lists sequentially in a multiple-baseline design. Participant-generated features were captured during treatment and coded in terms of feature category, total average number of features generated per trial, and total number of unique features generated per item. Item-level naming accuracy was analyzed using logistic mixed-effects regression models. Results Producing more participant-generated features was found to improve treatment response for trained but not untrained items in SFA, in contrast to Gravier et al. (2018). There was no effect of participant-generated feature diversity or any differential effect of feature category on SFA treatment outcomes. Conclusions Patient-generated features remain a key predictor of direct training effects and overall treatment response in SFA. Aphasia severity was also a significant predictor of treatment outcomes. Future work should focus on identifying potential nonresponders to therapy and explore treatment modifications to improve treatment outcomes for these individuals. Supplemental Material https://doi.org/10.23641/asha.12462596.

Intracellular expression of a single domain antibody reduces cytotoxicity of 15-acetyldeoxynivalenol in yeast.

15-Acetyldeoxynivalenol (15-AcDON) is a low molecular weight sesquiterpenoid trichothecene mycotoxin associated with Fusarium ear rot of maize and Fusarium head blight of small grain cereals. The accumulation of mycotoxins such as deoxynivalenol (DON) and 15-AcDON within harvested grain is subject to stringent regulation as both toxins pose dietary health risks to humans and animals. These toxins inhibit peptidyltransferase activity, which in turn limits eukaryotic protein synthesis. To assess the ability of intracellular antibodies (intrabodies) to modulate mycotoxin-specific cytotoxocity, a gene encoding a camelid single domain antibody fragment (V(H)H) with specificity and affinity for 15-AcDON was expressed in the methylotropic yeast Pichia pastoris. Cytotoxicity and V(H)H immunomodulation were assessed by continuous measurement of cellular growth. At equivalent doses, 15-AcDON was significantly more toxic to wild-type P. pastoris than was DON. In turn, DON was orders of magnitude more toxic than 3-acetyldeoxynivalenol. Intracellular expression of a mycotoxin-specific V(H)H within P. pastoris conveyed significant (p = 0.01) resistance to 15-AcDON cytotoxicity at doses ranging from 20 to 100 mug.ml(-1). We also documented a biochemical transformation of DON to 15-AcDON to account for the attenuation of DON cytotoxicity at 100 and 200 mug.ml(-1). The proof of concept established within this eukaryotic system suggests that in planta V(H)H expression may lead to enhanced tolerance to mycotoxins and thereby limit Fusarium infection of commercial agricultural crops.

Patient-reported cognitive and communicative functioning: 1 construct or 2?

OBJECTIVES: To examine the dimensionality of scales for measuring patient-reported cognitive and communicative functioning in a sample of stroke survivors and to evaluate the consequences for measurement of treating them as a single, undifferentiated construct. DESIGN: Secondary analysis of existing cross-sectional data. SETTING: Data were collected in outpatient rehabilitation clinics and in the community. PARTICIPANTS: Unilateral stroke survivors (N=316) 3 months or more postonset referred for participation in research. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Burden of Stroke Scale cognition and communication domain scales were evaluated by using confirmatory factor analysis, Rasch analysis, and tests of differential item functioning (DIF). To evaluate the impact of multidimensionality on the measurement of individual patients, separately estimated cognition and communication scores were compared. Combined and separately estimated scores were also examined for responsiveness to group differences in the presence of cognitive and communicative impairment. RESULTS: Factor analysis and Rasch model fit analyses equivocally supported the unidimensionality of the item pool. DIF analyses between participants with right versus left hemisphere stroke suggested multidimensionality. Scaling cognition and communication items separately resulted in different person scores for a significant number of patients and greater responsiveness to group differences. CONCLUSIONS: Patient-reported scales assessing communication along with more general cognitive activities may possess an internal structure that is inconsistent with a unidimensional measurement model with potential negative consequences for measurement.

What Is Really Needed to Provide Effective, Person-Centered Care for Behavioral Expressions of Dementia? Guidance from The Alzheimer's Association Dementia Care Provider Roundtable.

In April, 2019, the Alzheimer's Association Dementia Care Provider Roundtable convened to discuss common challenges faced when implementing person-centered, non-pharmacological practices in long-term care and other settings that provide care and programs for persons living with dementia, and to develop relevant, specific guidance from the perspective of administrative leaders from 23 long-term and community-based care provider organizations (representing home, community-based, and residential care). Guidance related to 5 practice areas emerged from the facilitated discussion: having a foundational person-centered culture, conceptualizing behaviors as expressions and focusing on behavioral support, identifying antecedents and placing person-centeredness before protocols, modifying training to promote person-centered culture, and valuing implementation flexibility. In developing the practice guidance, a related list of priority areas for research and policy were also identified.

Further Study of the Effects of Treatment Intensity on Outcomes of Sound Production Treatment for Acquired Apraxia of Speech: Does Dose Frequency Matter?

Purpose The aim of this study was to examine the effects of dose frequency, an aspect of treatment intensity, on articulation outcomes of sound production treatment (SPT). Method Twelve speakers with apraxia of speech and aphasia received SPT administered with an intense dose frequency and a nonintense/traditional dose frequency (SPT-T). Each participant received both treatment intensities in the context of multiple baseline designs across behaviors. SPT-Intense was provided for 3 hourly sessions per day/3 days per week; and SPT-T for 1 hour-long session per day/3 days per week. Twenty-seven treatment sessions were completed with each phase of treatment. Articulation accuracy was measured in probes of production of treated and untreated words. Results All participants achieved improved articulation of treated words with both intensities; there were no notable differences in magnitude of improvement associated with dose frequency. Positive response generalization to untrained words was found in 21 of 24 treatment applications; the cases of negligible response generalization occurred with SPT-T words. Conclusions Dose frequency (and corresponding total intervention duration) did not appear to impact treatment response for treated items. Disparate response generalization findings for 3 participants in the current study may relate to participant characteristics such as apraxia of speech severity and/or stimuli factors.

Cloning, expression, and characterization of a single-domain antibody fragment with affinity for 15-acetyl-deoxynivalenol.

A single-domain variable heavy chain (V(H)H) antibody fragment specific to the mycotoxin 15-acetyldeoxynivalenol (15-AcDON) was obtained after immunization of a llama (Llama glama) with the protein conjugate 15-DON-BSA plus TiterMax Classic adjuvant. After confirmation of a polyclonal response to DON toxin in both conventional (cIgG) and heavy chain antibody (HCAb) fractions, a V(H)H library was constructed from amplified cDNA by nested PCR. V(H)H fragments with binding affinity for the mycotoxin were selected by panning of the phagemid library against microtiter plates coated with 15-DON-OVA. The dominant clone (NAT-267) was expressed in E. coli and was purified as a V(H)H monomer (mNAT-267) at a final concentration of 1.3 mg mL(-1). Isolated NAT-267 V(H)H DNA was fused to the homopentamerization domain of the B subunit of verotoxin to generate the pentabody format of single-domain antibody (sAb). The V(H)H pentamer (pNAT-267) was expressed in E. coli and was purified at a final concentration of 1.0 mg mL(-1). Surface plasmon resonance (SPR) analysis of soluble mNAT-267 binding kinetics to immobilized 15-DON-Horse Radish Peroxidase (HRP) indicated a dissociation constant (K(D)) of 5microM. Competitive direct enzyme-linked immunosorbent assay (CD-ELISA) and fluorescence polarization assay (FPA) inhibition experiments with monomer and pentamer confirmed binding to 15-AcDON. Competitive inhibition FPAs with mNAT-267 and pNAT-267 determined IC(50) values of 1.24 and 0.50 microM, respectively, for 15-AcDON hapten. These values were similar to the IC(50) value of 1.42 microM for 15-AcDON given by polyclonal llama serum sampled 56 days after immunization. Competition formats for structurally related trichothecenes resulted in no cross-reactivity to: DON; 3-acetyldeoxynivalenol (3-AcDON); neosolaniol (NEO); diacetoxyscirpenol (DAS); and T-2 toxin. Our study confirmed that recombinant V(H)H fragments capable of binding low molecular weight haptens can be produced through the creation and panning of hyper-immunized single-domain (sdAb) libraries.

Analysis of Electrocardiograms Associated with Pediatric Electrical Burns.

The purpose of this study was to examine the utility of electrocardiograms (EKGs) for low-risk, low-voltage pediatric electrical burn victims. A retrospective chart review was conducted on 86 pediatric patients who presented to the children's hospital between 2000 and 2015 after sustaining electrical burns. Variables included source and estimated voltage, extent of injuries, length of stay, high risk factors, and EKG results. High risk factors included estimated voltage > 1000 V, lightning, tetany, symptoms, loss of consciousness, or seizures. Statistical analyses were conducted. Average age was 5 years. Of those who sustained burns, 84.5% (n = 71/84) had second-degree burns ≤ 1% TBSA or less. Eleven patients had high risk factors, 12.9% (n = 11/85) and most had length of stay < 3 days (91.8%; n = 78/85). Majority sustained burns from low-voltage (< 300 V) household electrical outlets, cords, or light bulb sockets (90.4%; n = 75/83). Among patients with available EKGs, 12 had arrhythmias on initial EKG (i.e., low right atrial rhythm, t-wave inversions, sinus tachycardia, bundle branch block; 20.7%; n = 12/58). All were transient and nonfatal. The data suggest that low estimated voltage (< 300 V) electrical injuries were associated with negative EKGs; however, due to the low rate of arrhythmias, a Fisher's exact test did not show significance, P = 0.09 (P > 0.05). Preliminary data suggest that most pediatric electrical burns are due to low voltage (< 300 V) household sources. Few have high risk factors or arrhythmias that were transient and nonfatal. These data suggest that low-risk, asymptomatic, low-voltage pediatric electrical burns may not require an initial screening EKG.

Effects of Treatment Intensity on Outcomes in Acquired Apraxia of Speech.

Purpose: This investigation was designed to examine the effects of treatment intensity (i.e., dose frequency) on the outcomes of Sound Production Treatment (SPT) for acquired apraxia of speech. Method: Five men with chronic apraxia of speech and aphasia received both intense SPT (3 hr per day/3 days per week) and nonintense/traditional SPT (SPT-T; 1 hr per day/3 days per week) in the context of single-case experimental designs. Each treatment was applied separately to a designated set of experimental words with 1 treatment applied at a time. Twenty-seven treatment sessions were conducted with each phase of treatment. Accuracy of articulation of target sounds within treated and untreated experimental words was measured during the course of the investigation. Results: All participants demonstrated improved articulation with both treatment intensities. Better maintenance of gains for treated items was found with SPT-T for 2 participants as measured at an 8-week posttreatment retention probe. Superior maintenance of increased accuracy of production of untreated items was also observed with SPT-T for all participants. Conclusion: A less intense (distributed) application of SPT facilitated better maintenance of improved articulatory accuracy for untreated items, and in some cases treated items, than intense SPT. Supplemental Materials: https://doi.org/10.23641/asha.5734053.

Maneuvering Together, Apart, and at Odds: Residents' Care Convoys in Assisted Living.

Objectives: Frail and disabled individuals such as assisted living residents are embedded in "care convoys" comprised of paid and unpaid caregivers. We sought to learn how care convoys are configured and function in assisted living and understand how and why they vary and with what resident and caregiver outcomes. Method: We analyzed data from a qualitative study involving formal in-depth interviews, participant observation and informal interviewing, and record review. We prospectively studied 28 residents and 114 care convoy members drawn from four diverse assisted living communities over 2 years. Results: Care convoys involved family and friends who operated individually or shared responsibility, assisted living staff, and multiple external care workers. Residents and convoy members engaged in processes of "maneuvering together, apart, and at odds" as they negotiated the care landscape routinely and during health crises. Based on consensus levels, and the quality of collaboration and communication, we identified three main convoy types: cohesive, fragmented, and discordant. Discussion: Care convoys clearly shape care experiences and outcomes. Identifying strategies for establishing effective communication and collaboration practices and promoting convoy member consensus, particularly over time, is essential to the creation and maintenance of successful and supportive care partnerships.

Audiological Assessment of Word Recognition Skills in Persons With Aphasia.

PURPOSE: The purpose of this study was to evaluate the ability of persons with aphasia, with and without hearing loss, to complete a commonly used open-set word recognition test that requires a verbal response. Furthermore, phonotactic probabilities and neighborhood densities of word recognition errors were assessed to explore potential underlying linguistic complexities that might differentially influence performance among groups. METHOD: Four groups of adult participants were tested: participants with no brain injury with normal hearing, participants with no brain injury with hearing loss, participants with brain injury with aphasia and normal hearing, and participants with brain injury with aphasia and hearing loss. The Northwestern University Auditory Test No. 6 (NU-6; Tillman & Carhart, 1966) was administered. Those participants who were unable to respond orally (repeating words as heard) were assessed with the Picture Identification Task (Wilson & Antablin, 1980), permitting a picture-pointing response instead. Error patterns from the NU-6 were assessed to determine whether phonotactic probability influenced performance. RESULTS: All participants with no brain injury and 72.7% of the participants with aphasia (24 out of 33) completed the NU-6. Furthermore, all participants who were unable to complete the NU-6 were able to complete the Picture Identification Task. There were significant group differences on NU-6 performance. The 2 groups with normal hearing had significantly higher scores than the 2 groups with hearing loss, but the 2 groups with normal hearing and the 2 groups with hearing loss did not differ from one another, implying that their performance was largely determined by hearing loss rather than by brain injury or aphasia. The neighborhood density, but not phonotactic probabilities, of the participants' errors differed across groups with and without aphasia. CONCLUSIONS: Because the vast majority of the participants with aphasia examined could be tested readily using an instrument such as the NU-6, clinicians should not be reticent to use this test if patients are able to repeat single words, but routine use of alternative tests is encouraged for populations of people with brain injuries.

What Matters in Semantic Feature Analysis: Practice-Related Predictors of Treatment Response in Aphasia.

Purpose: This study investigated the predictive value of practice-related variables-number of treatment trials delivered, total treatment time, average number of trials per hour, and average number of participant-generated features per trial-in response to semantic feature analysis (SFA) treatment. Method: SFA was administered to 17 participants with chronic aphasia daily for 4 weeks. Individualized treatment and semantically related probe lists were generated from items that participants were unable to name consistently during baseline testing. Treatment was administered to each list sequentially in a multiple-baseline design. Naming accuracy for treated and untreated items was obtained at study entry, exit, and 1-month follow-up. Results: Item-level naming accuracy was analyzed using logistic mixed-effect regression models. The average number of features generated per trial positively predicted naming accuracy for both treated and untreated items, at exit and follow-up. In contrast, total treatment time and average trials per hour did not significantly predict treatment response. The predictive effect of number of treatment trials on naming accuracy trended toward significance at exit, although this relationship held for treated items only. Conclusions: These results suggest that the number of patient-generated features may be more strongly associated with SFA-related naming outcomes, particularly generalization and maintenance, than other practice-related variables. Supplemental Materials: https://doi.org/10.23641/asha.5734113.

Contours of "here": Phenomenology of space for assisted living residents approaching end of life.

Informed by theory from environmental gerontology, this study investigates how assisted living residents who are approaching end of life navigate and experience space. Since its development, environmental gerontology has moved beyond the concept of person-environment fit to encompass aspects of place attachment and place integration, processes by which inhabited impersonal space becomes a place of individual personal meaning and this person-place relationship evolves with changing needs. Our study is a secondary data analysis of in-depth interviews completed with the first 15 residents (mean age 88, range 65-103; 8 white and 7 black) recruited from four diverse assisted living communities in metropolitan Atlanta. Using interpretative phenomenological analysis, we identify five overarching themes within and across assisted living communities and their subthemes. Findings show that participants experience a neutral theme of shrinking space, negative themes of confinement and vulnerability, and positive themes of safety and intimacy. Results dovetail with other phenomenologically based environmental gerontology research from community-dwelling populations that indicate behavioral changes to accommodate aging and health decline. Findings have implications for interventions to improve place integration in AL and enhance residents' quality of life at end of life, including developing strategies to promote small meaningful journeys within context of shrinking life space.

Cardiac troponin risk stratification based on 99th percentile reference cutoffs in patients with ischemic symptoms suggestive of acute coronary syndrome: influence of estimated glomerular filtration rates.

Cardiac troponin (cTn) assays were compared in 490 unselected patients with symptoms suggestive of acute coronary syndrome with varying renal functions for risk stratification. cTnI (Dade, Newark, NJ; Beckman, Chaska, MN; and Tosoh, South San Francisco, CA) and cTnT (Roche, Indianapolis, IN) measurements and estimated glomerular filtration rates (eGFRs) were obtained and classified along sex-derived cutoffs. The cTn levels were increased in 14% to 25% of patients. In 68%, the eGFR was 60 mL/min/1.73 m2 or more; in 17%, it was between 41 and 59; and in 15%, it was 40 or less. There were 36 deaths and 9 cardiac events. Risk stratification was significant at 30 days and 6 months (P < or = .05). Relative risks ranged from 3.1 to 3.7, and cumulative event rates ranged from 22.4% to 24.2% for an increased troponin level compared with 6.7% to 8.9% for a normal level. The 6-month event rate with an eGFR less than 60 mL/min/1.73 m2 and an increased troponin level ranged from 29.9% to 50.8% compared with 4.9% to 6.6% for a normal troponin level and an eGFR greater than 60 mL/min/1.73 m2 (P < .05). The eGFR in combination with an increased cTn level demonstrated the most powerful stratification.

Dynamic multipathway modeling of Cd bioaccumulation in Daphnia magna using waterborne and dietborne exposures.

We tested the predictive ability of the dynamic multipathway bioaccumulation model (DYMBAM) to characterize Cd accumulation in Daphnia magna, a species commonly used in toxicity tests and because of its sensitivity, particularly to metals, a species that is relied upon in ecological risk assessments. We conducted chronic exposure experiments in which D. magna were exposed to either dietborne Cd alone or to both dietborne and waterborne Cd. In the food-only treatments, the algae Chlamydomonas reinhardtii or Pseudokirchneriella subcapitata were pre-exposed to free Cd ion concentrations, [Cd(2+)], from 0.001 to 100nM (0.001-11microgL(-1)) then, on a daily feeding renewal basis, fed to D. magna over 21 days. In the water plus food treatment, D. magna were exposed for 21 days to the same range of [Cd(2+)] and fed with the same algal species that had been exposed to Cd at various concentrations. In the algal exposure media, Cd concentrations in algae were directly related to those in water and were characterized by a linear regression model using the log transformed concentration of the WHAM predicted Cd(2+) concentration. The DYMBAM was used with estimated values of the model constants for ingestion rate (0.08-0.34gg(-1)day(-1)) and growth rate (0.085-0.131day(-1)) based on our experimental data and with literature values for rate constants of Cd influx and efflux as well as Cd assimilation efficiency. Measured Cd concentrations in D. magna agreed with model predictions within a factor of 3. Using the model, we predict that food is an important contributor of Cd burden to D. magna, particularly at lower Cd exposure concentrations over an environmentally realistic gradient of free Cd in water. However, this cladoceran also takes up Cd from water and this exposure route becomes increasingly important at very high concentrations of free Cd (>10nM or 1.1microgL(-1)). Nevertheless, Cd produced lethal effects in D. magna that were exposed to this metal in water and diet, but exposure to Cd in food only did not result in toxic effects (as measured by survival and reproduction).

Auditory performance characteristics of the Computerized Revised Token Test (CRTT).

PURPOSE: To assess the Computerized Revised Token Test (CRTT) performance of individuals with normal hearing under several intensity conditions and under several spectral and temporal perturbation conditions. METHOD: Sixty normal-hearing listeners were randomly assigned to 1 of 3 groups. Group 1 provided performance-intensity information about CRTT performance using uncompressed acoustic stimuli. Groups 2 and 3 completed the CRTT using temporally and spectrally compressed and expanded stimuli. CRTT performance functions were plotted for each group. RESULTS: Group 1 required minimal audibility to perform maximally on this task. As expected, Groups 2 and 3 showed significant differences across subtests, regardless of distortion condition. Mean differences in performance between successive conditions for Group 2 increased beyond 40% time compressed. There was 1 significant difference for the time-expanded condition. There were no differences across frequency compressed and expanded conditions. CONCLUSION: Young listeners require limited signal gain on the CRTT to achieve maximum performance. Time and frequency compression and expansion results were consistent with previous findings with varying types of speech stimuli. The results have implications for administration and interpretation of the CRTT administered to persons from other populations and will help in the development of a normative database for the CRTT.

Rasch modeling of revised token test performance: validity and sensitivity to change.

The purpose of this research was to examine the validity of the 55-item Revised Token Test (RTT) and to compare traditional and Rasch-based scores in their ability to detect group differences and change over time. The 55-item RTT was administered to 108 left- and right-hemisphere stroke survivors, and the data were submitted to Rasch analysis. Traditional and Rasch-based scores for a subsample of 60 stroke survivors were submitted to analyses of variance with group (left hemisphere with aphasia vs. right hemisphere) and time post onset (3 vs. 6 months post onset) as factors. The 2 scoring methods were compared using an index of relative precision. Forty-eight items demonstrated acceptable model fit. Misfitting items came primarily from Subtest IX. The Rasch model accounted for 71% of the variance in the responses to the remaining items. Intersubtest patterns of item difficulty were well predicted by item content, but unexpected within-subtest differences were found. Both traditional and Rasch person scores demonstrated significant group differences, but only the latter demonstrated statistically significant change over time. Analysis of relative precision, however, failed to confirm a significant difference between the 2 methods. The findings generally support the RTT's validity, but a minority of items appears to respond to a different construct. Also, within-subtest differences in item difficulty suggest the need for further examination of variability in impaired language performance. Finally, the results suggest an equivocal advantage for Rasch scores in detecting change over time.