Visual Attention to Semantic and Orthographic Associations in Fluent Aphasia: Evidence from Eye-Tracking.

BACKGROUND AND PURPOSE: We examined the allocation of visual attention in an association task by both neurotypical participants (n = 11) and adults with fluent aphasia (n = 12). RESEARCH DESIGN: Participants were presented with a picture (e.g., a basket) followed by a semantically related association (i.e., "strawberry") and an orthographically related association (i.e., "b," the first letter of "basket"). ANALYSIS: An eye tracker recorded their eye movements for three areas of interest (AOI): the picture, the semantic associate, and the orthographic associate, over 1396 observations. RESULTS: Results showed that both neurotypical participants and participants with aphasia looked longer at the semantic associate than at the picture, and this difference was more pronounced for neurotypicals than for people with aphasia (PWA). Neurotypicals also looked longer than the PWA group at the orthographic associate than at the prior picture. Regarding eye fixation counts, both participant groups looked more frequently at the semantic associate than at either the picture or the orthographic associate. Notably, this pattern was more pronounced among neurotypical participants than PWA. CONCLUSIONS: Our findings emphasize the importance of semantic associations in fluent aphasia and suggest a potential rehabilitative approach in speech and language therapy.

Multilevel factors predict treatment response following semantic feature-based intervention in bilingual aphasia.

Semantic feature-based treatments (SFTs) are effective rehabilitation strategies for word retrieval deficits in bilinguals with aphasia (BWA). However, few studies have prospectively evaluated the effects of key parameters of these interventions on treatment outcomes. This study examined the influence of intervention-level (i.e., treatment language and treatment sessions), individual-level (baseline naming severity and age), and stimulus-level (i.e., lexical frequency, phonological length, and phonological neighborhood density) factors on naming improvement in a treated and untreated language for 34 Spanish-English BWA who completed 40 hours of SFT. Results revealed significant improvement over time in both languages. In the treated language, individuals who received therapy in their L1 improved more. Additionally, higher pre-treatment naming scores predicted greater response to treatment. Finally, a frequency effect on baseline naming accuracy and phonological effects on accuracy over time were associated with differential treatment gains. These findings indicate that multilevel factors are influential predictors of bilingual treatment outcomes.

The effects of adding attention training to naming treatment for individuals with aphasia.

AIM: Given the ever-increasing evidence for the co-occurrence of attention impairments and language disorders in chronic aphasia, this study aimed to compare the effects of two naming treatment programs, one with and one without attention training components, on the naming performance of participants with aphasia. MATERIALS AND METHODS: This was a single-subject crossover study in which six people with chronic aphasia and different degrees of naming and attention impairments participated. Two treatment programs were implemented for each participant, with the sequence of the treatments with crossover design. Each program consisted of 12 treatment sessions plus pre- and post-treatment assessment sessions (15 weeks for each participant). The visual analysis and WEighted STatistics methods were employed for data analysis. RESULTS: Based on visual analysis, both treatments improved in comparison to the baseline phase. Statistical analysis revealed that the number of participants with significant naming improvement following combined program (5 participants) was larger than the number of participants showing improvement following completion of the single, program. CONCLUSION: Although integrating attention training into a conventional treatment for anomia can increase the effect of treatment on naming ability, more studies are required to clarify the role of attention in remediating naming impairments in aphasia.

Combining executive function training and anomia therapy in chronic post-stroke aphasia: A preliminary study of multidimensional effects.

PURPOSE: The influential relationship between executive functioning and aphasia rehabilitation outcomes has been addressed in a number of studies, but few have studied the effect of adding executive function training to linguistic therapies. The present study aimed to measure the effects of combining, within therapy sessions, executive function training and anomia therapy on naming and discourse abilities in people with chronic aphasia. METHOD: A single-case experimental design with multiple baselines across participants was used. Four persons with chronic post-stroke aphasia received 12 sessions of a tailored treatment combining executive function training and semantic feature analysis (SFA) therapy. Naming accuracy of treated items was examined over the course of the treatment while control naming scores of untreated items and discourse measures were collected pre-treatment, immediately post-treatment, and 4 weeks post-treatment, in order to investigate the multidimensional effects of the treatment and their maintenance. RESULT: Naming skills improved in all participants for treated and untreated items, were maintained over time, and were accompanied by improved discourse abilities. Visual and statistical analyses showed a significant treatment effect for naming skills in three out of the four participants. CONCLUSION: A combination of executive function training and SFA treatment in people with chronic aphasia may improve both naming skills and discourse efficiency. Further studies are needed to substantiate these promising preliminary results.

"I don't know who you are": anomia for people's names in Alzheimer's disease.

It is well known that difficulty in the retrieval of people's names is an early symptom of Alzheimer's Disease Dementia (ADD), but there is a controversy about the nature of this deficit. In this study, we analyzed whether the nature of the difficulty in retrieving proper names in ADD reflects pre-semantic, semantic, or post-semantic difficulties. To do so, 85 older adults, 35 with ADD and 50 cognitively healthy (CH), completed a task with famous faces involving: recognition, naming, semantic questions, and naming with phonological cues. The ADD group scored lower than the CH group in all tasks. Both groups showed a greater capacity for recognition than naming, but this difference was more pronounced in the ADD group. Additionally, the ADD group showed significantly fewer semantic errors than the CH group. Overall results suggest that the difficulties people with ADD have in naming reflect a degradation at semantic level.

Baseline Conceptual-Semantic Impairment Predicts Longitudinal Treatment Effects for Anomia in Primary Progressive Aphasia and Alzheimer's Disease.

Background: An individual's diagnostic subtype may fail to predict the efficacy of a given type of treatment for anomia. Classification by conceptual-semantic impairment may be more informative. Aims: This study examined the effects of conceptual-semantic impairment and diagnostic subtype on anomia treatment effects in primary progressive aphasia (PPA) and Alzheimer's disease (AD). Methods & Procedures: At baseline, the picture and word versions of the Pyramids and Palm Trees and Kissing and Dancing tests were used to measure conceptual-semantic processing. Based on norming that was conducted with unimpaired older adults, participants were classified as being impaired on both the picture and word versions (i.e., modality-general conceptual-semantic impairment), the picture version (Objects or Actions) only (i.e., visual-conceptual impairment), the word version (Nouns or Verbs) only (i.e., lexical-semantic impairment), or neither the picture nor the word version (i.e., no impairment). Following baseline testing, a lexical treatment and a semantic treatment were administered to all participants. The treatment stimuli consisted of nouns and verbs that were consistently named correctly at baseline (Prophylaxis items) and/or nouns and verbs that were consistently named incorrectly at baseline (Remediation items). Naming accuracy was measured at baseline, and it was measured at three, seven, eleven, fourteen, eighteen, and twenty-one months. Outcomes & Results: Compared to baseline naming performance, lexical and semantic treatments both improved naming accuracy for treated Remediation nouns and verbs. For Prophylaxis items, lexical treatment was effective for both nouns and verbs, and semantic treatment was effective for verbs, but the pattern of results was different for nouns -- the effect of semantic treatment was initially nonsignificant or marginally significant, but it was significant beginning at 11 Months, suggesting that the effects of prophylactic semantic treatment may become more apparent as the disorder progresses. Furthermore, the interaction between baseline Conceptual-Semantic Impairment and the Treatment Condition (Lexical vs. Semantic) was significant for verb Prophylaxis items at 3 and 18 Months, and it was significant for noun Prophylaxis items at 14 and 18 Months. Conclusions: The pattern of results suggested that individuals who have modality-general conceptual-semantic impairment at baseline are more likely to benefit from lexical treatment, while individuals who have unimpaired conceptual-semantic processing at baseline are more likely to benefit from semantic treatment as the disorder progresses. In contrast to conceptual-semantic impairment, diagnostic subtype did not typically predict the treatment effects.

Speech and lexico-semantic errors during direct cortical stimulation mapping of the language-dominant hemisphere: effects of object and action naming.

OBJECTIVE: In this retrospective study, the authors aimed to establish the stereotactically defined probability distribution for speech (i.e., anarthria, speech arrest) and lexico-semantic errors (i.e., anomia) through direct cortical stimulation (DCS) by using two tasks: action naming and object naming. They also analyzed the patterns of interindividual variability in the localization of the language sites involved, and investigated whether any patient or lesion location factors were associated with greater variability. METHODS: Eighty-one Italian-speaking patients who underwent awake surgery between 2010 and 2021 for low- and high-grade gliomas in eloquent areas of the language-dominant hemisphere were entered in the analyses. The intraoperative DCS protocol included automatic speech tasks, object naming, and action naming. The position of the tags, as depicted on the intraoperative video or photograph, was transposed into Montreal Neurological Institute space. Subsequently, a 2D scatterplot and cluster analysis were performed. Associations between various clinical and radiological characteristics and the quantity of positive stimulated sites were determined by univariate analyses using binary logistic regression. Associated variables (p < 0.2) were included in stepwise multivariate logistic regression with backward elimination (p < 0.05). RESULTS: A total of 1380 cortical sites were stimulated, with a positive response in 511 cases (37%). Most anarthric errors were triggered when stimulating the left precentral gyrus, and most speech arrest errors were elicited when stimulating the left posterior inferior frontal gyrus. Anomias were found in the left inferior frontal gyrus and in the posterior part of the left temporal lobe for object naming. DCS to the left dorsal premotor cortex elicited anomic errors for action naming. Anomias were also elicited during DCS to the left posterior temporal lobe, with both object and action naming. CONCLUSIONS: The distribution of speech and lexico-semantic errors is in line with the current literature. The action-naming results are new and mostly involve the dorsal premotor cortex. These findings stress the importance of maximizing the use of different language tasks during surgery, because even when looking for the same type of errors, different tasks may be better suited to map specific brain regions. DCS with action and object naming identifies more positive sites than object naming alone.

Dissociation of reading and naming in ventral occipitotemporal cortex.

Lesions in language-dominant ventral occipitotemporal cortex (vOTC) can result in selective impairment of either reading and naming, resulting in alexia or anomia. Yet, functional imaging studies that show differential activation for naming and reading do not reveal activity exclusively tuned to one of these inputs. To resolve this dissonance in the functional architecture of vOTC, we used focused stimulation to the vOTC in 49 adult patients during reading and naming, and generated a population-level, probabilistic map to evaluate if reading and naming are clearly dissociable within individuals. Language mapping (50 Hz, 2,829 stimulations) was performed during passage reading (216 positive sites) and visual naming (304 positive sites). Within vOTC we isolated sites that selectively disrupted reading (24 sites, 11 patients) or naming (27 sites in 12 patients), and those that disrupted both processes (75 sites in 21 patients). The anteromedial vOTC had a higher probability of producing naming disruption while posterolateral regions resulted in greater reading specific disruption. Between them lay a multi-modal region where stimulation disrupted both reading and naming. This work provides a comprehensive view of vOTC organization - the existence of heteromodal cortex critical to both reading and naming, along with causally dissociable unimodal naming cortex, and a reading-specific visual word form area in vOTC. Their distinct roles as associative regions may thus relate to their connectivity within the broader language network that is disrupted by stimulation, more than to highly selective tuning properties. Our work also implies that pre-surgical mapping of both reading and naming is essential for patients requiring vOTC resections, as these functions are not co-localized and such mapping may prevent the occurrence of unexpected deficits.

Anterior Skull Base Abnormalities in Congenital Anosmia.

INTRODUCTION: The structures of the skull and the brain are related to each other. Prior work in individuals with isolated congenital anosmia (ICA) showed that these individuals were characterized by olfactory bulb (OB) defects. The aim of this study was to compare the morphological pattern of the anterior skull base surrounding the OB between individuals with ICA and normosmic controls. We meant to investigate whether these features can help distinguish abnormalities from normal variation. METHODS: We conducted a retrospective study to acquire T2-weighted magnetic resonance images from individuals diagnosed with ICA (n = 31) and healthy, normosmic controls matched for age and gender (n = 62). Between both groups, we compared the depth and width of the olfactory fossa, the angle of the ethmoidal fovea, as well as the angle of the lateral lamella of the cribriform plate. Within the ICA group, we further performed subgroup analyses based on the presence or absence of the OB, to investigate whether the morphology of the anterior skull base relates to the presence of OBs. The diagnostic performance of these parameters was evaluated using receiver operating characteristic analysis. RESULTS: Individuals with ICA exhibited a flattened ethmoid roof and shallower olfactory fossa when compared to controls. Further, the absence of the OB was found to be associated with a higher degree of flattening of the ethmoid roof and a shallow olfactory fossa. We reached the results in the following areas under the receiver operating characteristic curves: 0.80 - angle of fovea ethmoidalis, 0.76 - depth of olfactory fossa, 0.70 - angle of lateral lamella of the cribriform plate for significant differentiation between individuals with ICA and normosmic controls. CONCLUSION: Individuals with ICA exhibited an unusual anterior skull base surrounding the OB. This study supports the idea of an integrated development of OB and anterior skull base. Hence, the morphological pattern of the anterior skull base surrounding the OB helps distinguish individuals with ICA from normosmic controls and may therefore be useful for the diagnosis of ICA, although it is certainly not an invariable sign of congenital anosmia.

Early within therapy naming probes as a clinically-feasible predictor of anomia treatment response.

This study investigated the relationship between early within-therapy probe naming performance and anomia therapy outcomes in individuals with aphasia. Thirty-four adults with chronic, post-stroke aphasia participated in the Aphasia Language Impairment and Functioning Therapy (Aphasia LIFT) programme, comprised of 48 h of comprehensive aphasia therapy. Sets of 30 treated and 30 untreated items identified at baseline were probed during impairment therapy which targeted word retrieval using a combined semantic feature analysis and phonological component analysis approach. Multiple regression models were computed to determine the relationship between baseline language and demographic variables, early within-therapy probe naming performance (measured after 3 h of impairment therapy) and anomia treatment outcomes. Early within-therapy probe naming performance emerged as the strongest predictor of anomia therapy gains at post-therapy and at 1-month follow-up. These findings have important clinical implications, as they suggest that an individual's performance after a brief period of anomia therapy may predict response to intervention. As such, early within-therapy probe naming may provide a quick and accessible tool for clinicians to identify potential response to anomia treatment.

Anomia: Deciphering Functional Neuroanatomy in Primary Progressive Aphasia Variants.

Naming decline is one of the most common symptoms of primary progressive aphasia (PPA). Most studies on anomia in PPA are performed without taking into account PPA variants, especially for action naming. Only limited data are available for the neuroanatomical basis of anomia considering differences in the pathogenesis of PPAs. The aim of our study is to investigate the associations between anomia severity for both noun and verb naming and gray matter (GM) atrophy, as well as accompanying functional connectivity (FC) changes in three PPA variants. A total of 17 patients with non-fluent (nfvPPA), 11 with semantic (svPPA), and 9 with logopenic (lvPPA) PPA variants were included in the study and underwent cognitive/naming assessments and brain MRIs. Voxel-based morphometry was performed to evaluate GM volume. A resting-state functional MRI was applied to investigate FC changes in the identified GM areas. The study shows that different brain regions are involved in naming decline in each PPA variant with a predominantly temporal lobe involvement in svPPA, parietal lobe involvement in lvPPA, and frontal lobe involvement in nfvPPA. Separate data for object and action naming in PPA variants are provided. The obtained results mainly correspond to the current understanding of language processing and indicate that the evaluation of language impairments is preferable for each PPA variant separately. A further analysis of larger cohorts of patients is necessary to confirm these preliminary results.

Using a combined working memory - Semantic feature analysis approach to treat anomia in aphasia: A Pilot Study.

INTRODUCTION: The purpose of the study was to pilot a working memory (WM) - and modified Semantic Feature Analysis (SFA) approach to treat word finding deficits in a group of people with aphasia (PwA). Two research questions were posed: 1. Will the group of PwA be able to complete the WM tasks used in the approach? 2. Will the approach improve naming performance in PwA? METHOD: Three individuals with mild - moderate aphasia participated in this singlesubject multiple baseline treatment design. Pre-treatment assessments of language, and pre- to post-treatment assessments of WM abilities were carried out. The treatment protocol incorporated WM and linguistic tasks in order to improve naming accuracy across two treatment lists. Probes were carried out prior to treatment on each list, and at one-month following completion of treatment. Two outcome measures were obtained: Percent accuracy in completing the WM steps, and treatment effect sizes (Beeson & Robey, 2006). Additionally, modified t-tests (Crawford & Garthwaite, 2012; Crawford & Howell, 1998), were calculated in which post-treatment WM measures were compared against neurotypical control groups to detect any improvements in WM functions. RESULTS: All three participants completed the WM steps with a high degree of accuracy. A range of small to large ESs were obtained for all three participants across the two treated lists, while no meaningful ESs were obtained for the control (untreated) list. All three participants demonstrated improved scores across most of the WM measures with significant improvements noted on certain WM assessments. CONCLUSIONS: The findings revealed that the WM - SFA approach can be used successfully in individuals with mild - moderate aphasia. The proposed approach holds promise as feasible intervention designed to remediate anomia in PwA.

Comparison of the Effect of Four Transcranial Direct Current Stimulation Configurations on Picture-Naming Improvement in Non-Fluent Aphasia: A Randomized Clinical Trial.

Background: Anomia is a language disorder that negatively affects communication abilities in people with aphasia (PWA). We aimed to compare the effect of transcranial direct current stimulation (tDCS) over the left and right inferior frontal gyrus (IFG) and superior temporal gyrus (STG) on the picture-naming accuracy and reaction time in PWA. Methods: A randomized, single-blind, sham-controlled crossover trial was conducted in 2021 at Mobasher Kashani Clinic, Hamadan, Iran. Sixteen patients received both five days of real-tDCS (1 mA for 20 minutes) and five days of sham-tDCS with a seven-day washout period in between. Using the Persian aphasia naming test, picture-naming accuracy and reaction time on 50 images were assessed at baseline, real-tDCS, and sham-tDCS stages. The data were analyzed using STATA software, version 11.0. P<0.05 was considered statistically significant. Results: Sixteen non-fluent PWA participated in the study. Of all patients, 64% benefited from tDCS over the STG and 18% over the IFG. The results showed that real-tDCS had a significant effect on the picture-naming accuracy (P=0.003) and the Persian-Western aphasia battery-one score (P=0.01), whereas sham-tDCS had no noticeable effects. Both the real- and sham-tDCS had no significant effect on the reaction time (P=0.28). Conclusion: Five sessions of individualized tDCS protocol (1 mA for 20 minutes) were adequate to improve picture-naming accuracy in patients with chronic aphasia.

Treatment-induced neuroplasticity after anomia therapy in post-stroke aphasia: A systematic review of neuroimaging studies.

We systematically reviewed the literature on neural changes following anomia treatment post-stroke. We conducted electronic searches of CINAHL, Cochrane Trials, Embase, Ovid MEDLINE, MEDLINE-in-Process and PsycINFO databases; two independent raters assessed all abstracts and full texts. Accepted studies reported original data on adults with post-stroke aphasia, who received behavioural treatment for anomia, and magnetic resonance brain imaging (MRI) pre- and post-treatment. Search results yielded 2481 citations; 33 studies were accepted. Most studies employed functional MRI and the quality of reporting neuroimaging methodology was variable, particularly for pre-processing steps and statistical analyses. The most methodologically robust data were synthesized, focusing on pre- versus post-treatment contrasts. Studies more commonly reported increases (versus decreases) in activation following naming therapy, primarily in the left supramarginal gyrus, and left/bilateral precunei. Our findings highlight the methodological heterogeneity across MRI studies, and the paucity of robust evidence demonstrating direct links between brain and behaviour in anomia rehabilitation.

Novel participant-level meta-analytic evidence for AbSANT efficacy.

The current study employed interrupted time series (ITS) models to analyze all available (published and unpublished) Abstract Semantic Associative Network Training (AbSANT) data. AbSANT is a semantically focused anomia treatment that targets not only concrete but abstract words, unique among existing anomia treatments. However, evidence to date for the positive effects of AbSANT comes only from small-sample, single-subject design studies, limiting the strength of this evidence and the inferences that can be drawn from it. The statistical power and greater representativeness afforded by this larger aggregated sample enabled us to look for group-level efficacy evidence for AbSANT, examine specific questions about AbSANT's direct training and generalization effects, and identify potential predictors and mechanisms of AbSANT treatment response. We found that across 33 participants from four different data sources, AbSANT appears to be a robust word retrieval therapy protocol, with overall direct training and generalization effects that were more meaningful than exposure effects. Similar to previous smaller-sample study conclusions, we found that in this large sample, training abstract words results not only in larger direct training effects than training concrete words, but also larger generalization effects, suggesting that while AbSANT successfully improves both abstract and concrete word retrieval, it may be better suited for training abstract words. In general, direct training effects were more persistent after treatment ended than generalization effects and effects for concrete words were more persistent than for abstract words. Additionally, the effects of generalization appear to be distinct from the effects of simple exposure to words, and generalization effects are consistent with AbSANT's hypothesized mechanism of action: spreading activation from directly trained concepts to related concepts. Also consistent with this mechanism, we found that milder aphasia and both conceptual and lexical semantic processing ability predicted both direct training and generalization gains, and that executive function was predictive of generalization effects. These factors are thus important to consider when evaluating the appropriateness of AbSANT for individual clients.

Focusing on the locus of the breakdown for treatment of anomia: a pilot study.

The primary goal of this study was to evaluate the treatment effects of semantic feature analysis (SFA) and phonological components analysis (PCA) on word retrieval processing in persons with aphasia (PWAs). After identifying the locus of the breakdown in lexical retrieval processing, 15 monolingual native Persian speakers with aphasia were divided into two groups. After three naming trials, participants with dominant semantic deficits received SFA, and participants with primary phonological deficits were provided with PCA three times a week for eight weeks. Both approaches improved participants' naming and performance on language tests, including spontaneous speech, repetition, comprehension, and semantic processing. However, the correct naming of treated and untreated items was higher in mild-to-moderate participants, with mostly circumlocution and semantic paraphasias in the SFA group. The same holds for mild-to-moderate participants with mostly phonemic paraphasia who received PCA therapy. Moreover, the results showed that participants' baseline naming performance and semantic abilities could be associated with the treatment outcomes. Although limited by a lack of a control group, this study provided evidence supporting the possible benefits of focusing on the locus of the breakdown for treating anomia through SFA and PCA approaches, specifically in participants with mild to moderate aphasia. However, for those with severe aphasia, the treatment choice may not be as straightforward because several variables are likely to contribute to this population's word-finding difficulties. Replication with larger, well-stratified samples, use of a within-subjects alternating treatment design and consideration of treatments' long-term effects are required to better ascertain the effects of focusing on the locus of breakdown for treatment of anomia.

Anomia in left hemisphere stroke, multiple sclerosis and Parkinson's disease - a comparative study.

PURPOSE: To explore quantitative and qualitative features of anomia in participants with left-hemisphere stroke, Parkinson's disease, or multiple sclerosis. MATERIALS AND METHODS: This descriptive cross-sectional study compares signs of anomia within and across participants (n = 87), divided into four groups; moderate to severe anomia after stroke (MSAS, n = 19), mild anomia after stroke (MAS, n = 22), PD (n = 19) and MS (n = 27). Aspects analysed include naming accuracy and speed, the nature of incorrect responses, semantic and phonemic verbal fluency, information content in re-telling, and the relationship between test results and self-reports on word-finding difficulties and communicative participation. RESULTS: All groups had impaired verbal fluency, prolonged response times and reduced information content in re-telling. The MSAS group had significantly more signs of anomia than the other groups. Results from the other groups overlapped on a MAS-PD-MS continuum. Both semantically and phonologically incorrect responses were common in the stroke groups, while semantically incorrect ones predominated in the PD and MS groups. All four groups reported a similar negative impact on self-perceived communicative participation. Correlations between self-reports and test results were inconsistent. CONCLUSIONS: Anomia features have quantitative and qualitative similarities and differences across neurological conditions.

People with moderate or severe anomia after stroke not only exhibit more severe symptoms of word-finding difficulties but also manifest a wide variety of such symptoms, compared to people with Parkinson's disease or multiple sclerosis.The present findings underscore the need to ask patients about their self-perceived word-finding difficulties.Regardless of the degree of difficulties or the underlying condition, self-perceived word-finding difficulties can have a negative impact on communicative participation and should therefore be appropriately addressed.An assessment comprising aspects such as verbal fluency, connected-speech tasks and the measurement of response times in naming tasks may serve to affirm the self-reported word-finding difficulties.

Composite Indices of the Color-Picture Version of Boston Naming Test Have Better Discriminatory Power: Reliability and Validity in a Chinese Sample with Diverse Neurodegenerative Diseases.

BACKGROUND: The Boston Naming Test (BNT) is the most widely used measure to assess anomia. However, it has been criticized for failing to differentiate the underlying cognitive process of anomia. OBJECTIVE: We validated the color-picture version of BNT (CP-BNT) in a sample with diverse neurodegenerative dementia diseases (NDDs). We also verified the differential ability of the composite indices of CP-BNT across NDDs groups. METHODS: The present study included Alzheimer's disease (n = 132), semantic variant primary progressive aphasia (svPPA, n = 53), non-svPPA (n = 33), posterior cortical atrophy (PCA, n = 35), and normal controls (n = 110). We evaluated psychometric properties of CP-BNT for the spontaneous naming (SN), the percentage of correct responses on semantic cuing and word recognition cuing (% SC, % WR). Receiver operating characteristic analysis was used to examine the discriminatory power of SN alone and the composite indices (SN, % SC, and % WR). RESULTS: The CP-BNT had sufficient internal consistency, good convergent, divergent validity, and criterion validity. Different indices of CP-BNT demonstrated distinct cognitive underpinnings. Category fluency was the strongest predictor of SN (ß= 0.46, p < 0.001). Auditory comprehension tests highly associated with % WR (Sentence comprehension: ß= 0.22, p = 0.001; Word comprehension: ß= 0.20, p = 0.001), whereas a lower visuospatial score predicted % SC (ß= -0.2, p = 0.001). Composite indices had better predictability than the SN alone when differentiating between NDDs, especially for PCA versus non-svPPA (area under the curve increased from 63.9% to 81.2%). CONCLUSION: The CP-BNT is a highly linguistically relevant test with sufficient reliability and validity. Composite indices could provide more differential information beyond SN and should be used in clinical practice.

The eyes speak when the mouth cannot: Using eye movements to interpret omissions in primary progressive aphasia.

Though it may seem simple, object naming is a complex multistage process that can be impaired by lesions at various sites of the language network. Individuals with neurodegenerative disorders of language, known as primary progressive aphasias (PPA), have difficulty with naming objects, and instead frequently say "I don't know" or fail to give a vocal response at all, known as an omission. Whereas other types of naming errors (paraphasias) give clues as to which aspects of the language network have been compromised, the mechanisms underlying omissions remain largely unknown. In this study, we used a novel eye tracking approach to probe the cognitive mechanisms of omissions in the logopenic and semantic variants of PPA (PPA-L and PPA-S). For each participant, we identified pictures of common objects (e.g., animals, tools) that they could name aloud correctly, as well as pictures that elicited an omission. In a separate word-to-picture matching task, those pictures appeared as targets embedded among an array with 15 foils. Participants were given a verbal cue and tasked with pointing to the target, while eye movements were monitored. On trials with correctly-named targets, controls and both PPA groups ceased visual search soon after foveating the target. On omission trials, however, the PPA-S group failed to stop searching, and went on to view many foils "post-target". As further indication of impaired word knowledge, gaze of the PPA-S group was subject to excessive "taxonomic capture", such that they spent less time viewing the target and more time viewing related foils on omission trials. In contrast, viewing behavior of the PPA-L group was similar to controls on both correctly-named and omission trials. These results indicate that the mechanisms of omission in PPA differ by variant. In PPA-S, anterior temporal lobe degeneration causes taxonomic blurring, such that words from the same category can no longer be reliably distinguished. In PPA-L, word knowledge remains relatively intact, and omissions instead appear to be caused by downstream factors (e.g., lexical access, phonological encoding). These findings demonstrate that when words fail, eye movements can be particularly informative.

Treatment-induced neural reorganization in aphasia is language-domain specific: Evidence from a large-scale fMRI study.

Studies investigating the effects of language intervention on the re-organization of language networks in chronic aphasia have resulted in mixed findings, likely related to-among other factors-the language function targeted during treatment. The present study investigated the effects of the type of treatment provided on neural reorganization. Seventy individuals with chronic stroke-induced aphasia, recruited from three research laboratories and meeting criteria for agrammatism, anomia or dysgraphia were assigned to either treatment (N = 51) or control (N = 19) groups. Participants in the treatment group received 12-weeks of language intervention targeting sentence comprehension/production, naming, or spelling. At baseline and post-testing, all participants performed an fMRI story comprehension task, with blocks of auditorily-presented stories alternated with blocks of reversed speech. Participants in the treatment, but not control, group significantly improved in the treated language domain. FMRI region-of-interest (ROI) analyses, conducted within regions that were either active (or homologous to active) regions in a group of 22 healthy participants on the story comprehension task, revealed a significant increase in activation from pre-to post-treatment in right-hemisphere homologues of these regions for participants in the sentence and spelling, but not naming, treatment groups, not predicted by left-hemisphere lesion size. For the sentence (but not the spelling) treatment group, activation changes within right-hemisphere homologues of language regions were positively associated with changes in measures of verb and sentence comprehension. These findings support previous research pointing to recruitment of right hemisphere tissue as a viable route for language recovery and suggest that sentence-level treatment may promote greater neuroplasticity on naturalistic, language comprehension tasks, compared to word-level treatment.