Patrick J. Doyle

Verbal working memory and its relationship to sentence‐level reading and listening comprehension in persons with aphasia

Background: Working memory (WM) has gained recent attention as a cognitive construct that may account for language comprehension deficits in persons with aphasia (PWA) (Caspari, Parkinson, LaPointe, & Katz, 1998; Martin, Kohen, & Kalinyak‐Fliszar, 2008; Wright, Downey, Gravier, Love, & Shapiro, 2007). However, few studies have investigated individual differences in performance on sentence comprehension tasks as a function of WM capacity in PWA when WM demands are manipulated. Aims: The purposes of the current study were: (1) to examine the relationships among verbal WM, sentence comprehension, and severity of impairment in PWA and (2) to investigate the differential performance of high versus low verbal WM groups on sentence comprehension tasks in which task demands were manipulated by the length of the sentence stimuli, complexity of syntactic structure, and by presentation method which varied the time over which the linguistic material was available for computation. Methods & Procedures: A total of 20 PWA were divided into high and low WM groups based on a listening version of a WM sentence span task. Each participant completed a listening version (CRTT) and three reading versions (CRTT‐R) of the Computerised Revised Token Test as the sentence comprehension tasks. Outcomes & Results: The WM task significantly predicted performance on the CRTT conditions in which information was only temporarily available, thereby imposing greater WM demands on sentence comprehension. The verbal WM task was significantly correlated with aphasia severity and a principal components analysis revealed that the WM task, overall aphasia severity, and overall reading impairment level loaded on a single factor with 76% of shared variance. The low WM groups performance was significantly lower than the high WM group on the CRTT subtests with syntactically more complex structures and on the CRTT conditions with temporally restricted presentation methods. Conclusions: This verbal WM task was significantly and moderately correlated with the overall severity of aphasia as well as with both listening and reading sentence comprehension. The WM group differences emerged only in sentence comprehension tasks with greater WM demands. These results are consistent with the notion that WM effects are most evident when WM capacity is sufficiently taxed by the task demands (e.g., Caplan & Waters, 1999; Just & Carpenter, 1992).

The Burden of Stroke Scale (BOSS): Validating patient-reported communication difficulty and associated psychological distress in stroke survivors

Background: The Burden of Stroke Scale (BOSS) (Doyle et al., 2002) is a health-status assessment instrument designed to measure patient-reported difficulty in multiple domains of functioning, psychological distress associated with specific functional limitations, and,general well-being in stroke survivors. Aims : This study was designed to examine the discriminative and concurrent validity of the BOSS Communication Difficulty (CD) and Communication-Associated Psychological Distress (CAPD) scales. A secondary purpose was to provide a preliminary examination of the relationships between the BOSS CD and CAPD scales and aspects of subjective well-being, including the frequency with which participants reported experiencing general positive and negative emotional states. Methods & Procedures : The BOSS was administered as a face-to-face interviewer-assisted survey to 281 medically stable, community-dwelling stroke survivors selected from five collaborating centres in the USA. Prior to administration of the BOSS, all subjects were rated for severity of communication impairment using the Boston Diagnostic Aphasia Examination (BDAE) Severity Rating Scale (Goodglass, Kaplan, & Baressi, 2001) and were administered Subtest 8 of the Revised Token Test (RTT), (McNeil & Prescott, 1978). The discriminant validity of the BOSS CD and CAPD scales was examined by comparing scores in stroke survivors with (N = 135) and without (N = 146) communication impairment, and within the communicatively impaired sample when classified according to BDAE ratings and RTT performance. Concurrent validity of the BOSS CD and CAPD scales was examined by correlating BOSS scores with BDAE ratings and RTT performance. Finally, correlations between the BOSS CAPD, BOSS CD, Positive Mood, and Negative Mood scales were calculated. Outcomes & Results : Statistical analyses revealed significant differences between communicatively impaired and non-communicatively impaired subjects on the BOSS CD and CAPD scales, as well as significant differences between communicatively impaired subjects of differing severity levels classified both by BDAE severity ratings and RTT performance. Correlational analyses revealed moderately strong relationships among the BOSS CD scale, BDAE severity ratings, and RTT performance. Finally, correlations among the BOSS CAPD, CD, Positive Mood, and Negative Mood scales revealed true covarying relationships of moderate strength between the BOSS CAPD and CD scales, and also between the CAPD and Negative Mood Scales. Conclusions : These findings provide preliminary support for the discriminant and construct validity of the BOSS Communication Difficulty (CD) and Communication Associated Distress (CAPD) Scales, and provide an empirical rationale for further research into the relationships between functional status, patient-reported health perceptions, and subjective well-being in stroke survivors with communication disorders.

The Communicative Informativeness and Efficiency of Connected Discourse by Adults With Aphasia Under Structured and Conversational Sampling Conditions

Measuring communicative informativeness under conversational discourse conditions is perhaps the most valid means of determining the interpersonal verbal communication abilities of adults with apha...

A double-blind, placebo-controlled study of pharmacological and behavioural treatment of lexical-semantic deficits in aphasia

This investigation replicated and extended an earlier study of naming disorders (McNeil. et al. 1995) by administering a placebo and pharmacological agents (d-amphetamine and selegiline) in the presence and absence of a behavioural intervention termed lexical-semantic activation inhibition therapy (L-SAIT) to examine their effects on naming performance in two adults with stroke-induced aphasia. Results revealed acquisition and maintenance effects of L-SAIT on targeted lexical items, no effects of placebo or active pharmacological agents in the absence of L-SAIT, and no differential effects between placebo + L-SAIT and pharmacological agents + L-SAIT. Thus, positive treatment effects were attributed to L-SAIT. Generalization to untrained items within and across form class was not observed, nor was generalization to measures of informativeness of connected speech. Subject 1 evidenced improvement on the Rapid Automatized Naming Test (Denckla and Rudel 1976).

Treatment for apraxia of speech: Effects of targeting sound groups

A multiple baseline design was used to assess the effects of a treatment programme for sound errors with a speaker with moderately severe apraxia of speech (AOS) and Brocas aphasia. Treatment consisted of training correct production of three groups of sounds (i.e. stops, fricatives, and glides/liquids) in sentences containing multiple exemplars of those sounds. The treatment combined modelling, repetition, integral stimulation, Visual cueing, and response-contingent feedback and was applied sequentially to the groups of sounds. Acquisition effects of treatment were measured by evaluating production of trained sentences in probes. Response generalization effects were assessed by examining sound production in untrained sentences containing exemplars of trained sounds and untrained sentences containing untrained sounds. Treatment resulted in improved production for trained sound groups, with response generalization closely following acquisition effects. Generalization across sound groups was negligible. Additionally, measures of sentence duration were conducted for sentences produced in two baseline, one mid-treatment, and two end-of-treatment probes. Statistically significant reductions in duration were noted at the completion of treatment in comparison to baseline measures.

Linguistic validation of four parallel forms of a story retelling procedure

This study reports the development and validation of four parallel forms of a story retelling procedure. The equivalency of forms was based on the performance of 15 adults with aphasia on 12 operationally defined productive language variables including measures of (a) verbal productivity, (b) information content, (c) grammatical well-formedness, (d) phoneme production, and (e) verbal disruptions. The results revealed no significant differences among the four forms of the test for any of the dependent measures, and strong, positive and significant correlations among forms for 11 of the 12 dependent measures. These results suggest that a wide variety of productive language variables can be reliably measured using parallel forms of the story-retelling procedure described herein.

Comparing connected language elicitation procedures in persons with aphasia: Concurrent validation of the Story Retell Procedure

Background: The Story Retell Procedure (SRP) (Doyle et al., 1998) is a well‐described method for eliciting connected language samples in persons with aphasia (PWA). However, the stimuli and task demands of the SRP are fundamentally different from commonly employed picture description, narrative, and procedural description tasks reported in the aphasia literature. As such, the extent to which measures of linguistic performance derived from the SRP may be associated with those obtained from picture description, narrative, and procedural description tasks is unknown. This research was supported by VA Rehabilitation Research and Development Merit Review Project C3159R “Cognitive and linguistic mechanisms of language performance in aphasia” and the Geriatric Research, Education, and Clinical Center of the VA Pittsburgh Healthcare System. The authors gratefully acknowledge the generous participation of the volunteers for this study and the laboratory assistance of Jennifer Golovin and MaryBeth Ventura. Aims: To assess the concurrent validity of linguistic performance measures obtained from the SRP with those obtained from picture description, narrative, and procedural description tasks by examining the correlations and the magnitude differences across the linguistic variables among the elicitation tasks. Secondarily, we examined the relationship of the percentage of information units per minute (%IU/Min) to other linguistic variables within the SRP and across the other elicitation tasks. Methods and Procedures: This study compared the SRP to six different, frequently used sampling procedures (three sets of picture descriptions, one fairytale generation, one set of narratives, and one set of procedural description tasks) from which the same five verbal productivity, four information content, two grammatical, and two verbal disruption measures were computed. Language samples were elicited from 20 PWA, spanning the aphasia comprehension severity range. Tests of association and difference were calculated for each measure between the SRP and the other sampling methods. Outcomes & Results: Significant and strong associations were obtained between the SRP and the other elicitation tasks for most linguistic measures. The SRP produced either no significant or significantly greater instances of the dependent variable except for the type–token ratio, which yielded a significantly lower value than the other sampling procedures. Conclusions: The findings are interpreted as support for the concurrent validity of the SRP and as evidence that a single form of the SRP will yield a language sample that is generally equivalent in distribution to other sampling procedures, and one that is generally greater in quantity to those typically used to assess connected spoken language in PWA. Additionally, it was found that the %IU/Min metric predicted highly the information content linguistic measures on the SRP as well as on the other elicitation procedures. However, it did not predict well measures of verbal productivity, grammaticality, or verbal disruptions.

The Relationship Between Objective Measures and Listeners’ Judgments of the Communicative Informativeness of the Connected Discourse of Adults With Aphasia

In this study, the connected discourse of 25 adults with aphasia was rated on the dimension of “informativeness” by 11 unfamiliar listeners using a direct magnitude estimation (DME) procedure. Thes...

Effects of training multiple form classes on acquisition, generalization and maintenance of word retrieval in a single subject

A study by McNeil et nl. reported no generalization effects in two individuals with aphasia following application of a word finding treatment in which subjects were trained sequentially on lexical items arranged by form class. The present investigation examined, in one of the two subjects from the original study, whether training on lexical items from a variety of form classes concurrently would result in greater response generalization than was observed previously in this subject. Results replicated earlier findings with positive acquisition and maintenance effects and little evidence of generalization to untrained items within or across form classes.

Examining the facilitative effects of rhyme in a patient with output lexicon damage

A theory-driven treatment was designed to facilitate access to the impaired output lexicons of a 47-year-old woman with aphasia resulting from a left parietal haemorrhage. In the context of a multiple-baseline design, lists of rhymed word pairs from four semantic categories were trained using a systematic cueing hierarchy. Performance measures were based on the subjects generation of targeted words, verbally and in writing, when presented with a rhyme of the target. Results demonstrated positive acquisition, generalization and maintenance effects for treated and untreated items across semantic categories. Delayed generalization patterns may be explained by retrieval inhibition (Blaxton and Bookheimer 1993) or lateral inhibition (McClelland and Rumelhart 1981).