Language Processing In Aphasia Research Articles

Online Eye Tracking for Aphasia: A Feasibility Study Comparing Web and Lab Tracking and Implications for Clinical Use.

Studies using eye-tracking methodology have made important contributions to the study of language disorders such as aphasia. Nevertheless, in clinical groups especially, eye-tracking studies often include small sample sizes, limiting the generalizability of reported findings. Online, webcam-based tracking offers a potential solution to this issue, but web-based tracking has not been compared with in-lab tracking in past studies and has never been attempted in groups with language impairments. Patients with post-stroke aphasia (n=16) and age-matched controls (n=16) completed identical sentence-picture matching tasks in the lab (using an EyeLink system) and on the web (using WebGazer.js), with the order of sessions counterbalanced. We examined whether web-based eye tracking is as sensitive as in-lab eye tracking in detecting group differences in sentence processing. Patients were less accurate and slower to respond to all sentence types than controls. Proportions of gazes to the target and foil picture were computed in 100ms increments, which showed that the two modes of tracking were comparably sensitive to overall group differences across different sentence types. Web tracking showed comparable fluctuations in gaze proportions to target pictures to lab tracking in most analyses, whereas a delay of approximately 500-800ms appeared in web compared to lab data. Web-based eye tracking is feasible to study impaired language processing in aphasia and is sensitive enough to detect most group differences between controls and patients. Given that validations of webcam-based tracking are in their infancy and how transformative this method could be to several disciplines, much more testing is warranted.

Vigilant Attention During Cognitive and Language Processing in Aphasia.

Persons with aphasia (PWA) experience differences in attention after stroke, potentially impacting cognitive/language performance. This secondary analysis investigated physiologically measured vigilant attention during linguistic and nonlinguistic processing in PWA and control participants. To evaluate performance and attention in a language task, seven PWA read sentences aloud (linguistic task) and were compared to a previous data set of 10 controls and 10 PWA. To evaluate performance and attention in a language-independent task, 11 controls and nine PWA completed the Bivalent Shape Task (nonlinguistic task). Continuous electroencephalogram (EEG) data were collected during each session. A previously validated EEG algorithm classified vigilant-attention state for each experiment trial into high, moderate, distracted, or no attention. Dependent measures were task accuracy and amount of time spent in each attention state (measured by the number of trials). PWA produced significantly more errors than controls on the linguistic task, but groups performed similarly on the nonlinguistic task. During the linguistic task, controls spent significantly more time than PWA in a moderate-attention state, but no statistically significant differences were found between groups for other attention states. For the nonlinguistic task, amount of time controls and PWA spent in each attention state was more evenly distributed. When directly comparing attention patterns between linguistic and nonlinguistic tasks, PWA showed significantly more time in a high-attention state during the linguistic task as compared to the nonlinguistic task; however, controls showed no significant differences between linguistic and nonlinguistic tasks. This study provides new evidence that PWA experience a heightened state of vigilant attention when language processing demands are higher (during a linguistic task) than when language demands are lower (during a nonlinguistic task). Collectively, results of this study suggest that when processing language, PWA may allocate more attentional resources than when completing other kinds of cognitive tasks.

Initial evaluation of the TALES (technology and literacy engagement after stroke) programme targeting functional literacy and social engagement in people with aphasia after stroke

ABSTRACT Background and aims Literacy skills are typically affected in people with stroke aphasia, leading to reduced engagement in functional everyday reading/writing tasks, such as email/messaging via social media. The aim of this study was to investigate the outcomes of the TALES (Technology And Literacy Engagement after Stroke) programme, a group-based online literacy-focused programme for people with aphasia after stroke. This first evaluation of this programme aimed to examine outcomes related to feasibility, changes in language, literacy and self-ratings of communication skills. Methods Five participants with aphasia were assessed on a range of outcome measures relating to language and self-perception of communication skills. These were: the Western Aphasia Battery-Revised (WAB-R; (Kertesz, 2007)), literacy subtests from the Psycholinguistic Assessment of Language Processing in Aphasia (PALPA; (Kay et al., 1996)) and the Communication Outcomes after Stroke (COAST; (Long et al., 2008)). TALES consisted of a weekly group online session, 1:1 supported telehealth reading/writing practice and regular messaging via email. Results and main contribution From a descriptive statistics perspective, the mean gains across the cohort were 7.94 (from 84.24 to 92.18) on the WAB AQ (aphasia quotient), 8.92 (from 81.18 to 90.10) on the WAB LQ (language quotient). Additionally, there was a change in the mean scores for PALPA subtests (31, 37 and 40) observed between the pre-treatment assessment and post-treatment assessment. Finally, the mean score increased by 8.8 (from 49.40 to 58.20) on the COAST (max score = 80). Results indicated gains in literacy and communication measures as well as changes to self-rating of communication reflecting changes in communication confidence. Conclusions Mindful of the threats to the internal validity inherent in the study design, the reported online therapy can overcome barriers such as distance and mobility limitations and may provide greater accessibility to therapy for individuals with aphasia. TALES was a low-therapist-input yet reasonably intensive treatment approach which embedded language practice immediately in functional use through the social group format and personally-relevant written communication. Implications The TALES programme meets many neuroscience principles of neurorehabilitation including “use it or lose it”, salience and transference. Future research may usefully investigate the contribution of the group format versus the functional literacy components towards these potentially promising early data.

Motor-type aphasia in English and Spanish and its relation to the linguistic variables intervening in reading

Abstract This pilot study was designed to explore the way linguistic variables affect reading in English and Spanish in the context of motor-type aphasia. The participants were two speakers with English L1, two English-Spanish bilinguals, and four speakers with Spanish L1. The Boston Diagnostic Aphasia Examination (BDAE) and Psycholinguistic Assessments of Language Processing in Aphasia (PALPA) were used to assess the participants’ reading skills. L1 English, Spanish, and bilingual participants used both the lexical and sublexical route when reading, but utilized one route more than the other depending on their linguistic profile. L1 Spanish participants used the damaged phonological route, producing many neologisms or non-answers. L1 English participants, utilizing the lexical route, produced more lexicalizations than neologisms. The bilingual participants showed interlanguage interference by producing many spelling-sound regularizations. These results suggest that orthographic depth and different linguistic variables affect individuals with motor-type aphasia depending on the language they speak.

Validation and standardization of the Psycholinguistic Assessments of Language Processing in Aphasia (PALPA)

ABSTRACT Aims This study aimed to standardize and assess the psychometric properties of a selected protocol of subtests from the Psycholinguistic Assessments of Language Processing in Aphasia (PALPA), a battery of tests that measures a wide range of language abilities underpinned by a cognitive neuropsychological model of language processing. Methods One hundred healthy participants were recruited (mean age 64 ± 10.4 years) as part of a large population-based study assessing cognitive change in Amyotrophic Lateral Sclerosis (ALS) and were assessed using the PALPA protocol. Reliability was measured by means of internal consistency and test-retest reliability. Validity was assessed through an inter-correlational analysis between PALPA subtests and a correlational analysis between PALPA subtests and external variables. A supplementary validation study (n = 35) of the Auditory Sentence – Picture Matching subtest of the PALPA against the TROG-2, another test of grammatical and syntactic processing, was carried out. Results The PALPA protocol had good internal consistency (Cronbach’s alpha coefficient = 0.78). Intra-class correlations indicated moderate to excellent test-retest reliability (ICCs ranging from 0.62 to 0.93), with significant agreements (p <.05) between time points in most cases. Validity of PALPA subtests was demonstrated by significant positive correlations among PALPA subtests (especially between those measuring the same language construct, ranging from 0.41 to 0.74). Moreover, the PALPA subtests correlated equivalently with external variables such as age, years of education and IQ, which further supported construct validity. Conclusion This study has proven adequate reliability and validity of a standardized protocol of the PALPA. Based on results from the assessment of psychometric properties of the PALPA protocol studied, adjusted IQ-based PALPA scores were generated.

Speaking in the Brain: The Interaction between Words and Syntax in Sentence Production

This neuroimaging study investigated the neural infrastructure of sentence-level language production. We compared brain activation patterns, as measured with BOLD-fMRI, during production of sentences that differed in verb argument structures (intransitives, transitives, ditransitives) and the lexical status of the verb (known verbs or pseudoverbs). The experiment consisted of 30 mini-blocks of six sentences each. Each mini-block started with an example for the type of sentence to be produced in that block. On each trial in the mini-blocks, participants were first given the (pseudo-)verb followed by three geometric shapes to serve as verb arguments in the sentences. Production of sentences with known verbs yielded greater activation compared to sentences with pseudoverbs in the core language network of the left inferior frontal gyrus, the left posterior middle temporal gyrus, and a more posterior middle temporal region extending into the angular gyrus, analogous to effects observed in language comprehension. Increasing the number of verb arguments led to greater activation in an overlapping left posterior middle temporal gyrus/angular gyrus area, particularly for known verbs, as well as in the bilateral precuneus. Thus, producing sentences with more complex structures using existing verbs leads to increased activation in the language network, suggesting some reliance on memory retrieval of stored lexical-syntactic information during sentence production. This study thus provides evidence from sentence-level language production in line with functional models of the language network that have so far been mainly based on single-word production, comprehension, and language processing in aphasia.

Transcranial Direct Current Stimulation Investigations of Language Processing in Aphasia

Transcranial Direct Current Stimulation Investigations of Language Processing in Aphasia

Collaborative design of accessible information with people with aphasia

ABSTRACTBackground: People with aphasia report preferences for specially formatted health information materials, but there is little evidence that modified materials result in improved comprehension. Potential explanations for this include language included not taking account of aphasic processing difficulties, topics unrelated to aphasia, lack of clarity regarding the use of images, and the lack of end-user involvement in the design. Additionally, no definitive criteria for production of accessible information have been identified.Aims: The first aim of this study was to collaborate with people with aphasia in an iterative design process to develop and finalise accessible information materials. The second aim was to identify definitive criteria for use in the future production of information materials for people with aphasia.Methods and procedure: Prototype materials were developed for the study, based on criteria identified from the existing research into aphasia-accessible information, and on the evidence base concerning language processing in aphasia. Fourteen people with aphasia took part in two rounds of consensus group meetings and viewed information about aphasia presented within the prototype materials. Consensus points were identified within the groups through discussion and through ratings using Likert scales. The set of consensus points and ratings were adapted into criteria for graphic designers to incorporate into subsequent designs of the materials, in order to generate a final version, and related criteria.Outcomes and results: The group discussions and the ratings of materials led to the identification of an agreed layout within which to present information, and specific criteria for the following: information consisting of one proposition expressed via everyday words and canonical syntactic forms; one or two images relating directly to keywords; sans serif typography with keyword emphasis. Individual preferences with regard to image types were identified. Novel criteria were identified in the study, relating to layout, language, images and typography. These were added to the original set of criteria to form definitive criteria for use in the development of accessible aphasia materials.Conclusions: This study successfully involved people with aphasia in the design process to produce novel materials, and related design criteria. The resulting materials and criteria differ from those previously proposed, by reflecting directly people with aphasia’s views and preferences, and by incorporating language and images suitable for people with aphasia, based on the existing research evidence and the outcomes of this study. The materials and criteria have the potential to improve people with aphasia’s understanding of health information.

Abstract WP174: Intensive Phonology Treatment Promotes Recovery in Reading in Chronic Aphasia Post Stroke

Therapies specifically targeting naming deficits are common because these deficits remain one of the most common and pervasive deficits seen in post-stroke aphasia (Goodglass &amp; Wingfield, 1997). Past studies have used single lexical item retrieval (Nickels, 2002) as the framework for both semantic and phonological treatment. The efficacy of this technique is unclear when applied to reading, writing, and lexical retrieval deficits (Boyle, 2004a, 2004b; Coelho, McHugh, &amp; Boyle, 2000). This study aimed to resolve these issues by implementing an easy to replicate design with a randomized control trial. 12 subjects enrolled in intensive speech therapy at Austin Speech Labs were selected for the study. They were randomly assigned to a Semantic (ST) (n=6) or phonological treatment (PT) (n=6) group. Subjects received comprehensive pre and post-testing using the Western Aphasia Battery-Revised (WAB-R), Boston Naming Test (BNT). The subject’s phonological awareness was assessed using subtests of Psycholinguistic Assessment of Language Processing in Aphasia (PALPA).Each participant attended three hours of therapy for a total of 40 hours of therapy. PT: The first eight weeks focused on mastering individual consonants and vowels and blending sounds to read single words. The second 8-week module focused on training consonants clusters, and spelling. ST: The first and second module focused on describing object attributes to aid reading, naming, and writing. An independent T-test (p-value of .05) was used to examine significant differences found in the post-test scores between each group. A paired t-test (p-value=. 05) was run to determine significant differences in pre and post-test scores across both treatment groups. The majority of participants showed increases between pre and post-testing in all subtests. The phonology group showed significant increases in letter length spelling, letter sounding, spoken and written letter matching, and syllable length reading PALPA subtests. The Semantic group showed significant increases in the WAB verbal commands and repetition subtests as well as the PALPA and spoken and written letter matching subtest. Conclusion: Phonology focused treatment appears to be beneficial despite differences in underlying impairments.

Primary Progressive Aphasia: State-of-the-Science Symposium

Primary Progressive Aphasia: State-of-the-Science Symposium

Cortical sensitivity to spoken acoustic variability in persons with aphasia: an MEG study

Cortical sensitivity to spoken acoustic variability in persons with aphasia: an MEG study

Diffusion-tensor imaging of major white matter tracts and their role in language processing in aphasia

A growing literature is pointing towards the importance of white matter tracts in understanding the neural mechanisms of language processing, and determining the nature of language deficits and recovery patterns in aphasia. Measurements extracted from diffusion-weighted (DW) images provide comprehensive in vivo measures of local microstructural properties of fiber pathways. In the current study, we compared microstructural properties of major white matter tracts implicated in language processing in each hemisphere (these included arcuate fasciculus (AF), superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), inferior frontal-occipital fasciculus (IFOF), uncinate fasciculus (UF), and corpus callosum (CC), and corticospinal tract (CST) for control purposes) between individuals with aphasia and healthy controls and investigated the relationship between these neural indices and language deficits.Thirty-seven individuals with aphasia due to left hemisphere stroke and eleven age-matched controls were scanned using DW imaging sequences. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) values for each major white matter tract were extracted from DW images using tract masks chosen from standardized atlases. Individuals with aphasia were also assessed with a standardized language test in Russian targeting comprehension and production at the word and sentence level.Individuals with aphasia had significantly lower FA values for left hemisphere tracts and significantly higher values of MD, RD and AD for both left and right hemisphere tracts compared to controls, all indicating profound impairment in tract integrity. Language comprehension was predominantly related to integrity of the left IFOF and left ILF, while language production was mainly related to integrity of the left AF. In addition, individual segments of these three tracts were differentially associated with language production and comprehension in aphasia. Our findings highlight the importance of fiber pathways in supporting different language functions and point to the importance of temporal tracts in language processing, in particular, comprehension.

Usage-based approaches to aphasia

ABSTRACTBackground: Effects of word frequency on language comprehension and production are pervasive in speakers with and without aphasia. Frequency effects at the sentence level are likewise pervasive in neurotypical speakers, but have received relatively little attention in the aphasia literature. When discussed, frequency-based explanations have typically been dismissed as explanations of sentence-level deficits. Usage-based approaches to understanding the accessibility of clause and phrase structures are not widely used in aphasiology, in spite of their psycholinguistic plausibility.Aims: One aim is to show that evidence in support of probabilistic models of aphasic sentence comprehension and production has been available for a long time, but has lacked visibility. Our second aim is to respond to one of the few papers [Bastiaanse, R. Bouma, G., & Post, W. (2009). Linguistic complexity and frequency in agrammatic speech production. Brain and Language, 109, 18–28.] that directly challenge frequency-based explanations. The third aim is to discuss some of the reasons why probabilistic models in aphasia have been far slower to gain traction in aphasiology than in psycholinguistic research on neurotypical speakers.Methods & Procedures: We review available studies of probabilistic sentence-level deficits in aphasia. We revisit and reanalyse some of the data presented in Bastiaanse et al. [Bastiaanse, R. Bouma, G., & Post, W. (2009). Linguistic complexity and frequency in agrammatic speech production. Brain and Language, 109, 18–28.]Outcomes & Results: We find the data compatible in Bastiaanse et al. to be consistent with the predictions of a usage-based account. We argue that the paucity of studies of probabilistic and other usage-based effects in aphasia has its roots in the dichotomy drawn between “algorithmic” versus “heuristic” factors in sentence processing. We argue that this dichotomy is artificial. “Heuristics” are part and parcel of sentence processing in all speakers.Conclusions: The effect of usage—that is, of the individual’s past linguistic experience—is evident in the language of people with aphasia, as it is in speakers generally. We argue that usage-based approaches are promising because of the gradient and “noisy, but not random” nature of language processing in aphasia, and that they are natural companions to life-participation approaches to aphasia rehabilitation.

The relationships between the amount of spared tissue, percent signal change, and accuracy in semantic processing in aphasia

Recovery from aphasia, loss of language following a cerebrovascular incident (stroke), is a complex process involving both left and right hemispheric regions. In our study, we analyzed the relationships between semantic processing behavioral data, lesion size and location, and percent signal change from functional magnetic resonance imaging (fMRI) data. This study included 14 persons with aphasia in the chronic stage of recovery (six or more months post stroke), along with normal controls, who performed semantic processing tasks of determining whether a written semantic feature matched a picture or whether two written words were related. Using region of interest (ROI) analysis, we found that left inferior frontal gyrus pars opercularis and pars triangularis, despite significant damage, were the only regions to correlate with behavioral accuracy. Additionally, bilateral frontal regions including superior frontal gyrus, middle frontal gyrus, and anterior cingulate appear to serve as an assistive network in the case of damage to traditional language regions that include inferior frontal gyrus, middle temporal gyrus, supramarginal gyrus, and angular gyrus. Right hemisphere posterior regions including right middle temporal gyrus, right supramarginal gyrus, and right angular gyrus are engaged in the case of extensive damage to left hemisphere language regions. Additionally, right inferior frontal gyrus pars orbitalis is presumed to serve a monitoring function. These results reinforce the importance of the left hemisphere in language processing in aphasia, and provide a framework for the relative importance of left and right language regions in the brain.

AutoRAT at your fingertips: Introducing the new Russian Aphasia Test on a tablet

AutoRAT at your fingertips: Introducing the new Russian Aphasia Test on a tablet

Verbal Functions in Psychopathy.

The aim of this study was to compare the verbal functions and language skills of male psychopathic individuals (in prison and outside) with non-psychopaths. The purpose was therefore to analyze phonological processing, reading and writing skills, the meaning of words and images, and the understanding of sentences. Ninety individuals with an average age of 38.19 (SD = 7.67) voluntarily participated in this study. The data were collected in different settings: prisons, a private charitable organization, and private clinics and health centers. All participants completed the Psychopathy Checklist Revised and the Psycholinguistic Assessment of Language Processing in Aphasia, to assess psychopathy traits and language skills, respectively. Participants were allocated into four different groups: incarcerated psychopathic offenders (n = 13), non-incarcerated psychopathic non-offenders living in the community (n = 13), incarcerated non-psychopathic offenders (n = 25), and non-psychopathic non-offenders living in the community (n = 39). The results showed that the verbal functions and language skills between psychopaths and non-psychopaths are very similar, showing a common profile. The data presented indicate the need for more specific work opportunities for both groups within the correctional setting, with the use of appropriate language and individualized programs as necessary.

Crossed Dysgraphia: A case Report

Crossed Dysgraphia: A case Report

Conceptualising and measuring working memory and its relationship to aphasia

Background: General agreement exists in the literature that individuals with aphasia can exhibit a working memory deficit that contributes to their language-processing impairments. Although conceptualised within different working memory frameworks, researchers have suggested that individuals with aphasia have limited working memory capacity and impaired attention-control processes as well as impaired inhibitory mechanisms. However, across studies investigating working memory ability in individuals with aphasia, different measures have been used to quantify their working memory ability and identify the relationship between working memory and language performance. Aims: The primary objectives of this article are (1) to review current working memory theoretical frameworks, (2) to review tasks used to measure working memory, and (3) to discuss findings from studies that have investigated working memory as they relate to language processing in aphasia. Main Contribution: Although findings have been consistent across studies investigating working memory ability in individuals with aphasia, discussion of how working memory is conceptualised and defined is often missing, as is discussion of results within a theoretical framework. This is critical, as working memory is conceptualised differently across the different theoretical frameworks. They differ in explaining what limits capacity and the source of individual differences as well as how information is encoded, maintained, and retrieved. When test methods are considered within a theoretical framework, specific hypotheses can be tested and stronger conclusions that are less susceptible to different interpretations can be made. Conclusions: Working memory ability has been investigated in numerous studies with individuals with aphasia. To better understand the underlying cognitive constructs that contribute to the language deficits exhibited by individuals with aphasia, future investigations should operationally define the cognitive constructs of interest and discuss findings within theoretical frameworks.

Remediation of language processing in aphasia: Improving activation and maintenance of linguistic representations in (verbal) short-term memory

Background: Verbal short-term memory (STM) impairments are invariably present in aphasia. Word processing involves a minimal form of verbal STM, i.e., the time course over which semantic and phonological representations are activated and maintained until they are comprehended, produced, or repeated. Thus it is reasonable that impairments of word processing and verbal STM may co-occur. The co-occurrence of language and STM impairments in aphasia has motivated an active area of research that has revealed much about the relationship of these two systems and the effect of their impairment on language function and verbal learning (Freedman & Martin, 2001; Martin & Saffran, 1999; Trojano & Grossi, 1995). In keeping with this view a number of researchers have developed treatment protocols to improve verbal STM in order to improve language function (e.g., Koenig-Bruhin & Studer-Eichenberger, 2007). This account of aphasia predicts that treatment of a fundamental ability, such as STM, which supports language function, should lead to improvements that generalise to content and tasks beyond those implemented in treatment. Aims: We investigated the efficacy of a treatment for language impairment that targets two language support processes: verbal short-term memory (STM) and executive processing, in the context of a language task (repetition). We hypothesised that treatment of these abilities would improve repetition abilities and performance on other language tasks that require STM. Method: A single-participant, multiple-baseline, multiple-probe design across behaviours was used with a participant with conduction aphasia. The treatment involved repetition of words and nonwords under three “interval” conditions, which varied the time between hearing and repeating the stimulus. Measures of treatment effects included acquisition, maintenance, and follow-up data, effect sizes, and pre- and post-treatment performance on a test battery that varies the STM and executive function demands of language tasks. Outcomes & Results: Improvement of repetition was mostly specific to treated stimuli. Post-treatment measures of language ability indicated improvements in single and multiple word processing tasks, verbal working memory tasks, and verbal span. Conclusions: Treatment of STM and executive processes in the context of a word repetition task resulted in improvements in other non-treated language tasks. The approach used in this study can be incorporated into other language-processing tasks typically used in treatment of language disorders (e.g., sentence processing).

Als ‘A’ niet meer als ‘a’ wordt herkend. Een analyse van verworven woordblindheid

A right-handed patient, aged 72, manifested alexia without agraphia, a right homonymous hemianopia and an impaired ability to identify visually presented objects. He was completely unable to read words aloud and severely deficient in naming visually presented letters. He responded to orthographic familiarity in the lexical decision tasks of the Psycholinguistic Assessments of Language Processing in Aphasia (PALPA) rather than to the lexicality of the letter strings. He was impaired at deciding whether two letters of different case (e.g., A, a) are the same, though he could detect real letters from made-up ones or from their mirror image. Consequently, his core deficit in reading was posited at the level of the abstract letter identifiers. When asked to trace a letter with his right index finger, kinesthetic facilitation enabled him to read letters and words aloud. Though he could use intact motor representations of letters in order to facilitate recognition and reading, the slow, sequential and error-prone process of reading letter by letter made him abandon further training.