Relationship Between Eye Movements During Reading and Severity of Language Impairment in Persons with Aphasia

Eye movements reflect cognitive-linguistic processing of neurotypical readers. Numerous reading related eye movement measures are associated with language processing, including saccades, fixations, word skipping, and regressions. Eye movements have also been used to examine language processing and reading in disordered populations including persons with aphasia. This study examined whether eye movement measures (i.e., fixation duration, gaze duration, total viewing time, skipping rate, saccade amplitude, regression path duration) obtained from connected text paragraph reading were associated with language severity (WAB-R) and reading comprehension skills (RCBA-2) in persons with various subtypes of aphasia as well as whether those same eye movement measures differed among persons with different subtypes of aphasia and neurotypical controls. Results indicated that regression path duration and word skipping reflected a significant difference between the control group and persons with aphasia. Additionally, there was a significant, strong, positive correlation between first fixation duration and severity of language impairment for persons with Broca’s aphasia, indicating longer fixation duration is associated with less severe language impairment

Lexical and sublexical analysis of single-word reading and writing errors

Within a dual-route neuropsychological model, two distinct but interrelated pathways are used to read and write, known as the lexical and sublexical routes. Individuals with reading and writing deficits often exhibit impairments in one or both of these routes, and therefore must rely on the combined power of the integrated system in print processing tasks. The resultant errors reflect varying degrees of lexical and sublexical accuracy in a single production. However, no system presently exists to analyze bimodal errors robustly in both routes. The goal of this project was to develop a system that simultaneously, quantitatively, and qualitatively captures lexical and sublexical errors for single-word reading and writing tasks. This system evaluates responses hierarchically in both routes according to proximity to a target. Each response earns a bivariate score [sublexical, lexical], which is plotted along x and y axes. This scoring system was developed using data from a novel treatment study for patients with acquired alexia/agraphia. Repeated-measures multivariate analyses of variance and post hoc analyses revealed a significant treatment effect in both the lexical and sublexical systems. Qualitative analyses were also conducted to evaluate patterns of change in both the trained and untrained modalities, in the sublexical and lexical systems. Overall, the results of this study indicate that treatment-induced evolution of reading/writing responses can be comprehensively represented by this novel scoring system.2018-07-07T00:00:00

Expectation in Visual Symbolic Processing of Environmental Symbols in People with Fluent Aphasia

The purpose of this study was to examine aspects of visual symbolic processing in those individuals with fluent aphasia, and how it compares to that of their lexical ability. Two groups of participants were examined: a group with fluent aphasia, and a group of non-neurologically damaged controls. Participants were administered four computer based expectation tasks, two of which were symbolic, and two which were lexical. Each task contained a simple and a complex level. Participants were required to determine if the final stimulus, within a set of four, was congruent or incongruent. The measures taken included both reaction time and accuracy. Results suggest significant differences in reaction times for individuals with aphasia and non-neurologically damaged individuals. Individuals with aphasia also identified fewer incongruent stimuli correctly. Within the aphasia group, statistical significance was approached between the simple symbolic condition and simple lexical condition. If this study were completed with a larger sample size, results could indicate a relative preservation of the non-verbal symbolic system as compared to the lexical system for simple conditions. Strong correlations were also noted for several opposing non-verbal and lexical conditions

Telepractice in the Communication Treatment of Individuals with Post-stroke Aphasia: Systematic Review

Telepractice, a branch of telehealth, which is the delivery of services to distant sites employing telecommunication, has been developing rapidly nowadays. Owing to the nature of the condition and treatment foci in aphasia, telepractice has been identified as a potential mode for intervention to persons with aphasia (PWA) in the field of speech-language pathology. Based on the American Speech-Language Hearing Association (2005), telepractice is considered a means to extend services to a wider context overcoming the barriers of transportation, costs, and limited availability of services. Thus, exploration of treatment accessibility to underserved populations in middle/low-income countries or rural areas via telepractice is warranted. The primary objectives of this study are to systematically review literature on telepractice of speech-language pathology services for PWA, with a focus to synthesize and analyze data that will be useful to low-income countries to consider telepractice as an alternate option and also to contribute to broaden the evidence base of aphasia practices via telepractice and include the newest available evidence. A systematic review was conducted in this study following the guidelines of Cochrane Handbook (Higgins et al., 2020). The study utilized a systematic search based on PRISMA guidelines and included 11 articles following a thorough screen for eligibility. A pre-designed coding manual was utilized in order to extract relevant data. All the included studies evaluated the feasibility of telepractice in intervention and to investigate the effectiveness of treatment programs conducted via teletherapy. A majority of the participants (72%) included in the review are PWA secondary to strokes. The treatment areas studies targeted are word retrieval, language skills, communication skills and language and communication skills, with communication skills being the area covered in highest number of studies. The review found that telepractice in the targeted treatment programs is feasible and effective. However, the included articles lack strong methodological designs limiting the certainty of the evidence. Participant-perceived data indicated some advantages of telepractice, such as overcoming transport/cost barriers, receival of higher intensity of treatment, and facilitations for non-verbal strategies to improve language and communication skills. In addition, the results revealed that all but one of the included studies was completed in a high-income country. Most of the findings also lack adequate details on therapy receival and delivery setting dynamics from a standpoint of replicating the studies or in order to generalize the findings. In conclusion, the current review shows limited evidence guidelines for the use of telepractice in rural and middle/low-income countries. There is a need to explore simple affordable technology options in telepractice and evaluate their effectiveness in low/middle-income contexts. Empirical data on efficacy of telepractice for PWA drawn from strong methodological designs should also be considered to encourage evidence-based clinical practice using telepractice in those contexts

The relationship between non-orthographic language abilities and reading performance in chronic aphasia : an exploration of the primary systems hypothesis

PURPOSE : This study investigated the relationship between non-orthographic language abilities and reading in order to examine assumptions of the primary systems hypothesis and further our understanding of language processing poststroke. METHOD : Performance on non-orthographic semantic, phonologic, and syntactic tasks, as well as oral reading and reading comprehension tasks, was assessed in 43 individuals with aphasia. Correlation and regression analyses were conducted to determine the relationship between these measures. In addition, analyses of variance examined differences within and between reading groups (within normal limits, phonological, deep, or global alexia). RESULTS : Results showed that non-orthographic language abilities were significantly related to reading abilities. Semantics was most predictive of regular and irregular word reading, whereas phonology was most predictive of pseudohomophone and nonword reading. Written word and paragraph comprehension were primarily supported by semantics, whereas written sentence comprehension was related to semantic, phonologic, and syntactic performance. Finally, severity of alexia was found to reflect severity of semantic and phonologic impairment. CONCLUSIONS : Findings support the primary systems view of language by showing that non-orthographic language abilities and reading abilities are closely linked. This preliminary work requires replication and extension; however, current results highlight the importance of routine, integrated assessment and treatment of spoken and written language in aphasia.The first author was supported by the American Speech-Language-Hearing Foundation New Century Scholars Doctoral Scholarship and the University of Washington Research Training in Speech & Hearing Sciences National Institute on Deafness and Other Communication Disorders training grant (T32000033).https://pubs.asha.org/journal/jslhrhj2019Speech-Language Pathology and Audiolog

Consequences of bi-literacy in bilingual individuals: in the healthy and neurologically impaired

Background. In the current global, cross-cultural scenario, being bilingual or multilingual is a norm rather than an exception. In such an environment an individual may be actively involved in reading and writing in all their languages in addition to speaking them. Regular use of two or more languages is termed as bilingualism and being able to read and write in both of them is referred to as bi-literacy. Research indicates that bilingualism has an impact on language production and cognition, specifically executive functions. Given the impact of literacy and bilingualism, the reasonable question that arises, is whether bi-literacy would offer an additional impact on language production and cognition. This becomes even more relevant in a multilingual, multi-cultural society such as India. We examined the impact of bi-literacy on oral language production (at word and connected speech level), comprehension and on non-verbal executive function measures in bi-literate bilingual healthy adults in an immigrant diaspora living in the UK. In addition to English, they were speakers of one of the South Indian languages (Kannada, Malayalam, Tamil and Telugu). The significance of bi-literacy among bilinguals assumes further importance in aphasia (language impairment due to brain damage). For those who have aphasia in one or more languages due to brain damage, the severity of impairment maybe different in both languages, also the modalities of language may be differentially affected. In particular, reading and writing maybe impaired differently in the languages used by a bi/multilingual. Manifestation of reading impairments are also dependent on the nature of the script of the language being read [e.g., Raman & Weekes (2005) report differential dyslexia in a Turkish-English speaker who exhibited surface dyslexia in English and deep dysgraphia in Turkish]. Our study contributes to the field of bilingual aphasia by focusing specifically on reading differing from the existing literature of aphasia in bilinguals, where the focus has predominantly been on language production and comprehension. Studying reading impairments provides a better understanding of how the reading impairments are manifested in the two languages, which will aid appropriate assessment and intervention. This research investigated the impact of bi-literacy in both populations (healthy adults and neurologically impaired) in two phases: Phase I (in UK) and Phase II (in India). Aim. Phase I investigated the impact of bi-literacy on oral language production (at word level and connected speech), comprehension and non-verbal executive function in bi-literate bilingual healthy adults. Phase II examined the reading impairments in two languages of bilingual persons with aphasia (BPWA). Methods. For Phase I, participants were thirty-four bi-literate bilingual healthy adults with English as their L2 and one of the Dravidian languages (Kannada, Malayalam, Tamil and Telugu) as their L1. We have used the term ‘print exposure’ as a proxy for literacy. They were divided into a high print exposure (HPE, n=22) and a low print exposure (LPE, n=12) group based on their performance on two tasks measuring L2 print exposure- grammaticality judgement task and sentence verification task. We also quantified their bilingual characteristics- proficiency, reading and writing characteristics and dominance. The groups were matched on years of education, age and gender. Participants completed a set of oral language production tasks in L2 (at word level) namely -verbal fluency, word and non-word repetition; comprehension tasks in L2 namely synonymy triplets task and sentence comprehension task (Chapter 2); oral narrative task in L2 (at connected speech level) (Chapter 3) followed by non-verbal executive function tasks tapping into inhibitory control (Spatial Stroop and Flanker tasks), working memory (visual n-back and auditory n-back) and task switching (colour-shape task) (Chapter 4). For Phase II, we characterized the reading abilities of four BPWA who spoke one of the Dravidian languages (Kannada, Tamil, Telugu) (alpha-syllabic) as their L1 and English (alphabetic) as their L2. We quantified their bilingual characteristics- proficiency, reading and writing characteristics and dominance. Subtests from the Psycholinguistic Assessment of Language Processing in Aphasia (PALPA; Kay, Lesser & Coltheart, 1992) were used to document the reading profile of BPWA in English and reading subtests from Reading Acquisition Profile (RAP-K; Rao, 1997) and words from Bilingual Aphasia test -Hindi (BAT; Paradis & Libben, 1987) were used to document the reading profile of BPWA in Kannada and Hindi respectively. Findings. Based on the findings of Phase I (i.e., results from Chapter 2-4), we found prominent differences between HPE and LPE on comprehension measures (synonymy triplets and sentence comprehension tasks). This is in contrast to the results observed in monolingual adults, were semantics is less impacted by print exposure. Moreover, our predictions that HPE will result in better oral language production skills were borne out in specific conditions-semantic fluency and non-word repetition task (at word level) and higher number of words in the narrative, higher verbs per utterance and fewer repetitions (at connected speech level). In addition, the non-verbal executive functions, we found no direct link between print exposure (in L2) and non-verbal executive functions in bi-literate bilinguals excepting working memory (auditory N-back task). Additionally, another consistency in our findings is that there seems to be a strong link between print exposure and semantic processing in our research. The findings on the semantic tasks have been consistent across comprehension (synonymy triplets task and sentence comprehension task) and production (semantic fluency) favouring HPE. The findings from Phase II (Chapter 5) reveal differences of reading characteristics in the two languages (with different scripts) of the four BPWA. This research provides preliminary evidence that a script related difference exists in the manifestation of dyslexia in bi-scriptal BPWA speaking a combination of alphabetic and alpha-syllabic languages. Conclusions. Our research contributes to the existing literature by highlighting the relationship between bi-literacy and language production, comprehension and non-verbal cognition where bi-literacy seems to have a higher impact on language than cognition. The contrary findings from the monolinguals and children literature, highlight the importance for considering nuances of bilingual research and specifically challenges the notion that semantic comprehension is not significantly affected by literacy. In the neurologically impaired population, our research provides a comprehensive profiling of reading abilities in BPWA in the Indian population with languages having different scripts. Using this profiling and classification, we are able to affirm the findings previously found in literature emphasizing the importance of script in the assessment of reading abilities in BPWA. Such profiling and classification assist in the development of bilingual models of reading aloud and classifying different types of reading impairments

Stroke and aphasia quality of Life Scale-39: investigating preliminary content validity of picture representations by people with mild to moderate aphasia

Speech-language pathologists must consider the clients’ quality of life (QoL) to provide effective and meaningful evidence-based treatment (ASHA, 2005). Quality of life assessment goes beyond language impairments and is often a key part of planning intervention. However, few QoL measures exist for people with aphasia (PWA). The Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39; Hilari, 2003) is one of the few valid and reliable measures used to assess QoL in people with mild to moderate aphasia. However, the validity and reliability of the SAQOL-39 has not been established for individuals with severe aphasia who are unable to read and comprehend the written items (Hilari & Byng, 2001). Proxy reports for people with severe aphasia are not reliable and can contribute to misinterpretation of people with severe aphasia and their QoL (Hilari & Byng, 2009). High-context color photographs may access intact linguistic processes in PWA by bypassing their reading deficits (McKelvey, Hux, Dietz, & Beukelman, 2010). Therefore, visual aids may enhance accessibility of written assessments like the SAQOL-39 for people with severe aphasia. Preliminary content validity has been established for high-context color photographs paired with SAQOL-39 items by normal aging adults (Brouwer, 2013). The present study aimed to continue to establish the content validity of the photographs by investigating how 10 adults with mild to moderate aphasia, aged 30-89 years, rated similarities of photographic representations of SAQOL-39 items, rated on a 7-point Likert scale. The present results supported high content validity of photographic representations. The overall mean rating of items was 6.40 and 92% of the photographs were rated a 6 or 7 at least 60% of the time, indicating most people with mild to moderate aphasia rated photographs highly similar to the written questions they were paired with. This study’s results suggest the photographs may make the SAQOL-39 more accessible for people with severe aphasia to self-report on their QoL. Further research is warranted to investigate accessibility of the photographs among the severe aphasia population

How does iReadMore therapy change the reading network of patients with central alexia?

Central alexia (CA) is an acquired reading disorder co-occurring with a generalised language deficit (aphasia). The roles of perilesional and ipsilesional tissue in recovery from post-stroke aphasia are unclear. We investigated the impact of reading training (using iReadMore, a therapy app) on the connections within and between the right and left hemisphere of the reading network of patients with CA. In patients with pure alexia, iReadMore increased feedback from left inferior frontal region (IFG) to the left occipital (OCC) region. We aimed to identify if iReadMore therapy was effective through a similar mechanism in CA patients.Participants with chronic post-stroke CA (n=23) completed 35 hours of iReadMore training over four weeks. Reading accuracy for trained and untrained words was assessed before and after therapy. The neural response to reading trained and untrained words in the left and right OCC, ventral occipitotemporal (vOT) and IFG was examined using event-related magnetoencephalography.The training-related modulation in effective connectivity between regions was modelled at the group level with Dynamic Causal Modelling.iReadMore training improved participants' reading accuracy by an average of 8.4% (range: -2.77 to 31.66) while accuracy for untrained words was stable. Training increased regional sensitivity in bilateral frontal and occipital regions, and strengthened feedforward connections within the left hemisphere. Our data suggests that iReadMore training in these patients modulates lower-order visual representations, as opposed to higher-order, more abstract ones, in order to improve word reading accuracy.SIGNIFICANCE STATEMENTThis is the first study to conduct a network-level analyses of therapy effects in participants with post-stroke central alexia. When patients trained with iReadMore (a multimodal, behavioural, mass practice, computer-based therapy), reading accuracy improved by an average 8.4% on trained items. A network analysis of the magnetoencephalography data associated with this improvement revealed an increase in regional sensitivity in bilateral frontal and occipital regions and strengthening of feedforward connections within the left hemisphere. This indicates that in CA patients iReadMore engages lower-order, intact resources within the left hemisphere (posterior to their lesion locations) to improve word reading. This provides a foundation for future research to investigate reading network modulation in different CA subtypes, or for sentence level therapy