Aphasic naming: what matters?

The British object and action naming test for intraoperative mapping (BOATIM): A standardised and clinically tested framework for awake brain surgery

BACKGROUND

Picture-naming tasks are widely used for identifying speech-eloquent regions during awake craniotomy. However, language-specific and culturally relevant task stimuli remain scarce. Current practices mostly rely on translated stimuli that do not reflect the everyday language use of the target speakers and might be susceptible to misinterpretations due to linguistic and cultural differences. Additionally, non-standardised homemade tasks are used. Here, we, for the first time, present the development, standardisation, and clinical application of two tests designed specifically for functional mapping in British English.

METHODS

115 object and 86 action stimuli were developed using the British National Corpus (BNC) and controlled for confounding psycholinguistic variables using normative data from native speakers. Optimization of the items for intraoperative use was done by first standardising the tests in healthy volunteers followed by their application during the electrical stimulation of language-eloquent regions in brain tumour patients. In the standardised data, the influence of word- and subject-related factors on performance, and the test-retest reliability was explored.

RESULTS

The final items achieved above 80% naming agreement. Object naming proved easier compared to action naming, with accuracy positively influenced by word frequency and negatively affected by the age-of-acquisition variable in both tasks. No subject-related effects were found. Excellent test-retest reliability confirmed the consistency of the tests in measuring language abilities. Positive maps obtained during intraoperative functional mapping demonstrated the sensitivity of the tests in detecting speech-eloquent regions.

CONCLUSION

The tests provide a reliable and robust tool containing stimuli that are linguistically and culturally appropriate to British-English speakers.

The Functional Origin of Oral Word Production Deficits in the Logopenic Variant of Primary Progressive Aphasia: A Systematic Review

BACKGROUND/OBJECTIVES

Oral word production (OWP) deficits are prominent in the logopenic variant of primary progressive aphasia (lvPPA); however, their functional origin remains unclear. Some studies suggest a lexical, post-lexical, or even a combined functional origin of these deficits. The aim of the present study was to synthesize and analyze the information on the functional origin of the OWP deficits in patients with lvPPA.

METHODS

A quantitative systematic literature review was carried out using four databases: CINAHL, PsycINFO, Linguistics and Language Behavior Abstracts, and PubMed. Fourteen studies, including a total of 243 patients with lvPPA, and reporting results on picture naming and/or word and/or pseudoword repetition, were selected.

RESULTS

The overall findings of this review highlighted that two main functional origins appear to explain the OWP deficits in lvPPA: a lexical impairment affecting lexical processing and a post-lexical impairment affecting phonological short-term memory. Interestingly, the possibility of a third functional origin, affecting the semantic processing level, was also suggested by some studies.

CONCLUSIONS

We concluded that the presence of different functional origins of OWP in this population may be explained, at least partially, by the diversity of assessment tasks used in studies and the varied manipulation and control of psycholinguistic properties of words (e.g., frequency, length), as well as the various interpretations and analyses of the participants' errors. Further studies are needed to substantiate these findings by examining all the components involved in OWP, carefully manipulating the psycholinguistic properties and qualitatively analyzing the errors made by lvPPA participants.

Psycholinguistic predictors of naming accuracy and decline in bilingual logopenic primary progressive aphasia: a cross-linguistic case study

Naming impairment is a hallmark of logopenic primary progressive aphasia (lvPPA), yet its effects in bilingualism remain understudied. This study examined naming accuracy in a 78-year-old Chinese-English bilingual woman with lvPPA over two years using a modified Boston Naming Test. Naming accuracy was higher in her second, but more frequently used language (English) than her first, but less frequently used language (Chinese). Regression analyses revealed that familiarity predicted naming in Chinese, while word length and age of acquisition influenced English. Decline was linked to age of acquisition in Chinese and emotional properties in English, highlighting language-specific patterns in bilingual lvPPA.

Naming in a multilingual context: Norms for the ICMR-Manipal colour picture corpus in Kannada from the Indian context

There have been many published picture corpora. However, more than half of the world's population speaks more than one language and, as language and culture are intertwined, some of the items from a picture corpus designed for a given language in a particular culture may not fit another culture (with the same or different language). There is also an awareness that language research can gain from the study of bi-/multilingual individuals who are immersed in multilingual contexts that foster inter-language interactions. Consequently, we developed a relatively large corpus of pictures (663 nouns, 96 verbs) and collected normative data from multilingual speakers of Kannada (a southern Indian language) on two picture-related measures (name agreement, image agreement) and three word-related measures (familiarity, subjective frequency, age of acquisition), and report objective visual complexity and syllable count of the words. Naming labels were classified into words from the target language (i.e., Kannada), cognates (borrowed from/shared with another language), translation equivalents, and elaborations. The picture corpus had > 85% mean concept agreement with multiple acceptable names (1-7 naming labels) for each concept. The mean percentage name agreement for the modal name was > 70%, with H-statistics of 0.89 for nouns and 0.52 for verbs. We also analyse the variability of responses highlighting the influence of bi-/multilingualism on (picture) naming. The picture corpus is freely accessible to researchers and clinicians. It may be used for future standardization with other languages of similar cultural contexts, and relevant items can be used in languages from different cultures, following suitable standardization.

Establishing and evaluating the gradient of item naming difficulty in post-stroke aphasia and semantic dementia

Anomia is a common consequence following brain damage and a central symptom in semantic dementia (SD) and post-stroke aphasia (PSA), for instance. Picture naming tests are often used in clinical assessments and experience suggests that items vary systematically in their difficulty. Despite clinical intuitions and theoretical accounts, however, the existence and determinants of such a naming difficulty gradient remain to be empirically established and evaluated. Seizing the unique opportunity of two large-scale datasets of semantic dementia and post-stroke aphasia patients assessed with the same picture naming test, we applied an Item Response Theory (IRT) approach and we (a) established that an item naming difficulty gradient exists, which (b) partly differs between patient groups, and is (c) related in part to a limited number of psycholinguistic properties - frequency and familiarity for SD, frequency and word length for PSA. Our findings offer exciting future avenues for new, adaptive, time-efficient, and patient-tailored approaches to naming assessment and therapy.

Characterising the Long-Term Language Impairments of Children Following Cerebellar Tumour Surgery by Extracting Psycholinguistic Properties from Spontaneous Language

Following cerebellar tumour surgery, children may suffer impairments of spontaneous language. Yet, the language processing deficits underlying these impairments are poorly understood. This study is the first to try to identify these deficits for four levels of language processing in cerebellar tumour survivors. The spontaneous language of twelve patients who underwent cerebellar tumour surgery (age range 3-24 years) was compared against his or her controls using individual case statistics. A distinction was made between patients who experienced postoperative cerebellar mutism syndrome (pCMS) and those who did not. Time since surgery ranged between 11 months and 12;3 years. In order to identify the impaired language processing levels at each processing level (i.e., lexical, semantic, phonological and/or morphosyntactic) nouns and verbs produced in the spontaneous language samples were rated for psycholinguistic variables (e.g., concreteness). Standard spontaneous language measures (e.g., type-token ratio) were calculated as well. First, inter-individual heterogeneity was observed in the spontaneous language outcomes in both groups. Nine out of twelve patients showed language processing deficits three of whom were diagnosed with pCMS. Results implied impairments across all levels of language processing. In the pCMS-group, the impairments observed were predominantly morphosyntactic and semantic, but the variability in nature of the spontaneous language impairments was larger in the non-pCMS-group. Patients treated with cerebellar tumour surgery may show long-term spontaneous language impairments irrespective of a previous pCMS diagnosis. Individualised and comprehensive postoperative language assessments seem necessary, given the inter-individual heterogeneity in the language outcomes.

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.

Patterns of performance on the animal fluency task in logopenic variant of primary progressive aphasia: A reflection of phonological and semantic skills

PURPOSE

This study aimed to characterize the quantitative (total number of correct words generated) and qualitative (psycholinguistic properties of correct words generated) performance patterns on the animal fluency task in individuals with the logopenic variant of primary progressive aphasia and to investigate the influence of phonological and semantic abilities to these patterns.

METHODS

Fifteen participants with lvPPA and twenty neurotypical adults completed the animal fluency task and an assessment battery to characterize their phonological and semantic abilities. We recorded the total number of correct words produced and their psycholinguistic properties. Group differences were analyzed using independent samples t-tests and analysis of covariance. Stepwise and multiple linear regression analyses were implemented to investigate the contribution of psycholinguistic properties on word generation as well as the role of phonological and semantic abilities on performance. We also investigated the mediating role of phonological and semantic abilities on the relationship between relevant psycholinguistic properties and word generation output.

RESULTS

Compared to neurotypical controls, participants with lvPPA produced fewer correct responses and more words with lower age of acquisition. The total number of correct words generated was predicted by the age of word acquisition, such that individuals who generated more responses, produced words acquired later in life. Phonology and semantics influenced the number of correct words generated and their frequency, age of acquisition, and semantic neighborhood density. Familiarity and arousal were driven by semantic abilities. Phonological abilities partially mediated the relationship between age of acquisition and word generation output.

CONCLUSIONS

This study provides valuable insights into the performance patterns of the animal fluency task in lvPPA. Individuals with lvPPA with more intact phonological and semantic abilities generated greater number of words with more complex psycholinguistic properties. Our findings contribute to the understanding of language processes underlying word retrieval in lvPPA.

Why is a flamingo named as pelican and asparagus as celery? Understanding the relationship between targets and errors in a speeded picture naming task

Speakers sometimes make word production errors, such as mistakenly saying pelican instead of flamingo. This study explored which properties of an error influence the likelihood of its selection over the target word. Analysing real-word errors in speeded picture naming, we investigated whether, relative to the target, naming errors were more typical representatives of the semantic category, were associated with more semantic features, and/or were semantically more closely related to the target than its near semantic neighbours were on average. Results indicated that naming errors tended to be more typical category representatives and possess more semantic features than the targets. Moreover, while not being the closest semantic neighbours, errors were largely near semantic neighbours of the targets. These findings suggest that typicality, number of semantic features, and semantic similarity govern activation levels in the production system, and we discuss possible mechanisms underlying these effects in the context of word production theories.

What Drives Task Performance in Animal Fluency in Individuals Without Dementia? The SMART-MR Study

PURPOSE

In this study, we aim to understand whether and how performance in animal fluency (i.e., total correct word count) relates to linguistic levels and/or executive functions by looking at sequence information and item-level metrics (i.e., clusters, switches, and word properties).

METHOD

Seven hundred thirty-one Dutch-speaking individuals without dementia from the Second Manifestations of ARTerial disease-Magnetic Resonance study responded to an animal fluency task (120 s). We obtained cluster size and number of switches for the task, and eight different word properties for each correct word produced. We detected variables that determine total word count with random forests, and used conditional inference trees to assess points along the scales of such variables, at which total word count changes significantly.

RESULTS

Number of switches, average cluster size, lexical decision response times, word frequency, and concreteness determined total correct word count in animal fluency. People who produced more correct words produced more switches and bigger clusters. People who produced fewer words produced fewer switches and more frequent words.

CONCLUSIONS

Concurrent with existing literature, individuals without dementia rely on language and executive functioning to produce words in animal fluency. The novelty of our work is that such results were shown based on a data-driven approach using sequence information and item-level metrics.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23713269.

Comparing two picture naming tasks in primary progressive aphasia: Insights from behavioural and neural results

Picture naming tests are widely used to evaluate language impairments in neurodegenerative diseases, especially in Primary Progressive Aphasia (PPA). The available tests differ for many factors affecting the performance, e.g. format of stimuli and their psycholinguistic properties. We aim to identify the most appropriate naming test to be used on PPA according to the clinical and research demands. We investigated the behavioural characteristics, i.e. proportion of correct responses and error type, and their neural correlates in two Italian naming tests, CaGi naming (CaGi) and naming subtest of the Screening for Aphasia in NeuroDegeneration battery (SAND), administered to 52 PPA patients who underwent an FDG-PET scan. We analysed the effectiveness of the tests in distinguishing PPA versus controls and among PPA variants, considering the psycholinguistic variables affecting performance. We explored the brain metabolic correlates of behavioural performance in the tests. SAND, differently from CaGi, has time limits for the response and its items are less frequent and acquired later. SAND and CaGi differed in terms of number of correct responses and error profile, suggesting a higher difficulty to name SAND items compared to CaGi. Semantic errors predominated in CaGi, while anomic and semantic errors were equally frequent in SAND. Both tests distinguished PPA from controls, but SAND outperformed CaGi in discriminating among PPA variants. FDG-PET imaging revealed a shared metabolic involvement of temporal areas associated with lexico-semantic processing, encompassing anterior fusiform, temporal pole, and extending to posterior fusiform in sv-PPA. Concluding, a picture naming test with response time limit and items which are less frequent and acquired later in life, as SAND, may be effective at highlighting subtle distinctions between PPA variants, improving the diagnosis. Conversely, a naming test without time limit for the response, as CaGi, may be useful for a better characterization of the nature of the naming impairment at the behavioural level, eliciting more naming errors than anomia, possibly helping in the development of rehabilitation protocols.

Stimulus- and Person-Level Variables Influence Word Production and Response to Anomia Treatment for Individuals With Chronic Poststroke Aphasia

PURPOSE

The impact of stimulus-level psycholinguistic variables and person-level semantic and phonological processing skills on treatment outcomes in individuals with aphasia requires further examination to inform clinical decision making in treatment prescription and stimuli selection. This study investigated the influence of stimulus-level psycholinguistic properties and person-level semantic and phonological processing skills on word production accuracy and treatment response.

METHOD

This retrospective analysis included 35 individuals with chronic, poststroke aphasia, 30 of whom completed typicality-based semantic feature treatment. Mixed-effects logistic regression models were used to predict binary naming accuracy (a) at baseline and (b) over the course of treatment using stimulus-level psycholinguistic word properties and person-level semantic and phonological processing skills as predictors.

RESULTS

In baseline naming, words with less complex lexical-semantic and phonological properties showed greater predicted accuracy. There was also an interaction at baseline between stimulus-level lexical-semantic properties and person-level semantic processing skills in predicting baseline naming accuracy. With treatment, words that were more complex from a lexical-semantic standpoint (vs. less complex) and less complex from a phonological standpoint (vs. more complex) improved more. Individuals with greater baseline semantic and phonological processing skills showed a greater treatment response.

CONCLUSIONS

This study suggests that future clinical research and clinical work should consider semantic and phonological properties of words in selecting stimuli for semantically based treatment. Furthermore, future clinical research should continue to evaluate baseline individual semantic and phonological profiles as predictors of response to semantically based treatment.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21256341.

Investigating the influence of semantic factors on word retrieval: Reservations, results and recommendations

There is consensus that word retrieval starts with activation of semantic representations. However, in adults without language impairment, relatively little attention has been paid to the effects of the semantic attributes of to-be-retrieved words. This paper, therefore, addresses the question of which item-inherent semantic factors influence word retrieval. Specifically, it reviews the literature on a selection of these factors: imageability, concreteness, number of semantic features, typicality, intercorrelational density, featural distinctiveness, concept distinctiveness, animacy, semantic neighbourhood density, semantic similarity, operativity, valence, and arousal. It highlights several methodological challenges in this field, and has a focus on the insights from studies with people with aphasia where the effects of these variables are more prevalent. The paper concludes that further research simultaneously examining the effects of different semantic factors that are likely to affect lexical co-activation, and the interaction of these variables, would be fruitful, as would suitably scaled computational modelling of these effects in unimpaired language processing and in language impairment. Such research would enable the refinement of theories of semantic processing and word production, and potentially have implications for diagnosis and treatment of semantic and lexical impairments.

Beyond Percent Correct: Measuring Change in Individual Picture Naming Ability

PURPOSE

Meaningful changes in picture naming responses may be obscured when measuring accuracy instead of quality. A statistic that incorporates information about the severity and nature of impairments may be more sensitive to the effects of treatment.

METHOD

We analyzed data from repeated administrations of a naming test to 72 participants with stroke aphasia in a clinical trial for anomia therapy. Participants were divided into two groups for analysis to demonstrate replicability. We assessed reliability among response type scores from five raters. We then derived four summary statistics of naming ability and their changes over time for each participant: (a) the standard accuracy measure, (b) an accuracy measure adjusted for item difficulty, (c) an accuracy measure adjusted for item difficulty for specific response types, and (d) a distance measure adjusted for item difficulty for specific response types. While accuracy measures address the likelihood of a correct response, the distance measure reflects that different response types range in their similarity to the target. Model fit was assessed. The frequency of significant improvements and the average magnitude of improvements for each summary statistic were compared between treatment groups and a control group. Effect sizes for each model-based statistic were compared with the effect size for the standard accuracy measure.

RESULTS

Interrater and intrarater reliability were near perfect, on average, though compromised somewhat by phonological-level errors. The effects of treatment were more evident, in terms of both frequency and magnitude, when using the distance measure versus the other accuracy statistics.

CONCLUSIONS

Consideration of item difficulty and response types revealed additional effects of treatment on naming scores beyond those observed for the standard accuracy measure. The results support theories that assume naming ability is decomposable into subabilities rather than being monolithic, suggesting new opportunities for measuring treatment outcomes.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.17019515.

What Drives Task Performance in Fluency Tasks in People With HIV?

Introduction: Fluency tasks require language (i.e., semantics, phonological output lexicon, and phonological assembly) and executive functions (i.e., inhibition; mental set shifting; updating, and monitoring). Little is known about whether people with human immunodeficiency virus (HIV) are more impaired on a specific type of fluency task and what aspects of language and executive functions drive such performance.

Aims: To understand (1) whether people with HIV are more impaired in animal, letter, or unconstrained fluency relative to a normative sample; (2) whether there exist differences between tasks relative to the total number of words; and (3) which aspects of executive function and language are involved in their performance.

Methods: Data from animal, letter, and unconstrained fluency of 50 Spanish-speaking people with HIV were analyzed. The number of switches and mean cluster size for each task and 10 word properties (e.g., frequency, age of acquisition, length in graphemes) for each of the correct words were measured. A chi-square test was used to address Aim 1, linear mixed effects models for Aim 2, and random forests and conditional inference trees for Aim 3. The results were cross-validated with a normative sample.

Results: People with HIV were not more impaired in animal, letter, or unconstrained fluency relative to a normative sample. People with HIV produced fewer words in letter fluency compared to animal and unconstrained fluency. In addition, they produced fewer words in animal fluency compared to unconstrained fluency. Number of switches emerged as the most important variable to predict the total number of correct words when considering the three tasks together and for each task separately. Word frequency was relevant to predict animal fluency, age of acquisition to predict letter fluency, and cluster size to predict unconstrained fluency. These results were cross-validated with the exception cluster size.

Conclusion: People with HIV rely on language (phonological output lexicon, not necessarily semantics) and executive functioning (updating and monitoring) to produce words in fluency tasks. These results concur with the current literature. Future work may correlate fluency scores with other tests measuring language and executive functions or study other types of fluency tasks (e.g., action, cities, supermarket, and professions).

Bilingual Abstract Semantic Associative Network Training (BAbSANT): A Polish-English case study

INTRODUCTION

This article presents a novel approach to anomia therapy (i.e., BAbSANT: Bilingual Abstract Semantic Associative Network Training) for bilingual persons with aphasia (B-PWA) that capitalizes both on lexico-semantic theories in bilingualism and general theories of semantic organization and learning. Based on previous work, we hypothesized that training abstract words in either language would promote within-language generalization, while training in the nondominant language would promote both within- and cross-language generalization.

METHODS

This case study used a single-subject A₁BA₂CA₃ design. The participant was living with aphasia secondary to stroke and spoke both Polish and English, with Polish being his native and dominant language. Phase B consisted of abstract word training in Polish and phase C consisted of abstract word training in English. Prior to initiating therapy, in addition to a comprehensive language battery, we administered a cognitive control task to explore the relationship between cognitive control and treatment outcome.

RESULTS

We found within-language generalization regardless of the trained language, replicating previous work in monolingual persons with aphasia, further supporting the utility of training abstract words. However, contrary to our second hypothesis, cross-language generalization only occurred when the stronger language was trained.

CONCLUSIONS

The discussion of the results of this case study is framed within previous work and theories of bilingualism. The lack of cross-language generalization when the weaker language was trained is discussed, taking into account nonverbal cognitive control deficits. In addition to showing the efficacy of BAbSANT, these results highlight the importance of considering cognitive control as a factor influencing therapeutic outcomes in anomia treatment in bilingual PWA.

The Croatian psycholinguistic database: Estimates for 6000 nouns, verbs, adjectives and adverbs

Psycholinguistic databases containing ratings of concreteness, imageability, age of acquisition, and subjective frequency are used in psycholinguistic and neurolinguistic studies which require words as stimuli. Linguistic characteristics (e.g. word length, corpus frequency) are frequently coded, but word class is seldom systematically treated, although there are indications of its significance for imageability and concreteness. This paper presents the Croatian Psycholinguistic Database (CPD; available at: https://doi.org/10.17234/megahr.2019.hpb ), containing 6000 Croatian nouns, verbs, adjectives and adverbs, rated for concreteness, imageability, age of acquisition, and subjective frequency. Moreover, we present computationally obtained extrapolations of concreteness and imageability to the remainder of the Croatian lexicon (available at: https://github.com/megahr/lexicon/blob/master/predictions/hr_c_i.predictions.txt ). In the two studies presented here, we explore the significance of word class for concreteness and imageability in human and computationally obtained ratings. The observed correlations in the CPD indicate correspondences between psycholinguistic measures expected from the literature. Word classes exhibit differences in subjective frequency, age of acquisition, concreteness and imageability, with significant differences between nouns, verbs, adjectives and adverbs. In the computational study which focused on concreteness and imageability, concreteness obtained higher correlations with human ratings than imageability, and the system underpredicted the concreteness of nouns, and overpredicted the concreteness of adjectives and adverbs. Overall, this suggests that word class contains schematic conceptual and distributional information. Schematic conceptual content seems to be more significant in human ratings of concreteness and less significant in computationally obtained ratings, where distributional information seems to play a more significant role. This suggests that word class differences should be theoretically explored.

Thalamic but Not Subthalamic Neuromodulation Simplifies Word Use in Spontaneous Language

Several investigations have shown language impairments following electrode implantation surgery for Deep Brain Stimulation (DBS) in movement disorders. The impact of the actual stimulation, however, differs between DBS targets with further deterioration in formal language tests induced by thalamic DBS in contrast to subtle improvement observed in subthalamic DBS. Here, we studied speech samples from interviews with participants treated with DBS of the thalamic ventral intermediate nucleus (VIM) for essential tremor (ET), or the subthalamic nucleus (STN) for Parkinson’s disease (PD), and healthy volunteers (each n = 13). We analyzed word frequency and the use of open and closed class words. Active DBS increased word frequency in case of VIM, but not STN stimulation. Further, relative to controls, both DBS groups produced fewer open class words. Whereas VIM DBS further decreased the proportion of open class words, it was increased by STN DBS. Thus, VIM DBS favors the use of relatively common words in spontaneous language, compatible with the idea of lexical simplification under thalamic stimulation. The absence or even partial reversal of these effects in patients receiving STN DBS is of interest with respect to biolinguistic concepts suggesting dichotomous thalamic vs. basal ganglia roles in language processing.

Effects of semantic variables on word production in aphasia

Words differ in the complexity of their semantic representations and their relationships to other words and these differences can be operationalised as a variety of semantic variables. The research presented here investigates how word production in aphasia is influenced by six feature-based semantic variables (number of near semantic neighbours, semantic similarity, number of semantic features, typicality, intercorrelational density, and distinctiveness). Previous research has reported inconsistent findings for some of the semantic variables, while others have not been previously studied in aphasia. Spoken picture naming data from a large group of individuals with aphasia with mixed spoken word production impairments (n = 175) and a sub-group who produced few phonological errors (n = 60) was analysed. We examined effects of the semantic variables on overall naming accuracy and on the occurrence of different error types (semantic errors overall, coordinate errors, omissions), while controlling for other psycholinguistic variables using generalised linear mixed effects models and Bayesian correlations. Across analyses, number of semantic features was the most important predictor with a facilitatory main effect on naming accuracy in the sub-group analysis. Number of semantic features, along with typicality and semantic similarity, also predicted error types and in some analyses these effects depended on the integrity of semantic processing. Effects of the semantic variables and their theoretical explanations and implications are discussed in light of previous research and models of word production.

The Moroccan Arabic verb and noun test for language mapping (MAVNT-LP) under nTMS and DES

To maximize tumor resection and minimize postoperative neurological sequelae, intraoperative Direct Electrical Stimulation (DES) coupled with preoperative Navigated Transcranial Magnetic Stimulation (nTMS) is adopted as a more valid procedure when a tumor is located in or near language-positive cortical and subcortical brain areas/networks. To map language functions peri- and intraoperatively, naming tasks are usually administered given their sensitivity and practicality in mapping language networks and their association with positive postoperative outcomes. Linguistic protocols designed for stimulation under nTMS are relatively scarce, and non-existent in the Arabic language. The present study attempts to fill these gaps by presenting the processes of development, piloting, and standardization of the first (Moroccan) Arabic object and action naming protocol for use preoperatively under nTMS, and intraoperatively under DES. The MAVNT-LP was developed in accordance with both DES and nTMS time requirements and was balanced for relevant psycholinguistic as well as intrinsic factors. The test underwent piloting on a population of 10 Moroccan Arabic (MA)-speaking individuals and was validated on a population of 50 participants. The standardized version of the test consisted of 61 nouns and 61 verbs. The 122 items included in the test were named accurately by at least 80% of the participants and had a high naming agreement. Correlations between psycholinguistic factors and lexical retrieval are reported and discussed. The MAVNT-LP was found to be a valid instrument for use in a clinical setting either as a planning tool or as a protocol used to stimulate eloquent brain areas under awake brain surgery.

The Cologne Picture Naming Test for Language Mapping and Monitoring (CoNaT): An Open Set of 100 Black and White Object Drawings

Language assessment using a picture naming task crucially relies on the interpretation of the given verbal response by the rater. To avoid misinterpretations, a language-specific and linguistically controlled set of unambiguous, clearly identifiable and common object-word pairs is mandatory. We, here, set out to provide an open-source set of black and white object drawings, particularly suited for language mapping and monitoring, e.g., during awake brain tumour surgery or transcranial magnetic stimulation, in German language. A refined set of 100 black and white drawings was tested in two consecutive runs of randomised picture order and was analysed in respect of correct, prompt, and reliable object recognition and naming in a series of 132 healthy subjects between 18 and 84 years (median 25 years, 64% females) and a clinical pilot cohort of 10 brain tumour patients (median age 47 years, 80% males). The influence of important word- and subject-related factors on task performance and reliability was investigated. Overall, across both healthy subjects and patients, excellent correct object naming rates (97 vs. 96%) as well as high reliability coefficients (Goodman-Kruskal's gamma = 0.95 vs. 0.86) were found. However, the analysis of variance revealed a significant, overall negative effect of low word frequency (p < 0.05) and high age (p < 0.0001) on task performance whereas the effect of a low educational level was only evident for the subgroup of 72 or more years of age (p < 0.05). Moreover, a small learning effect was observed across the two runs of the test (p < 0.001). In summary, this study provides an overall robust and reliable picture naming tool, optimised for the clinical use to map and monitor language functions in patients. However, individual familiarisation before the clinical use remains advisable, especially for subjects that are comparatively prone to spontaneous picture naming errors such as older subjects of low educational level and patients with clinically apparent word finding difficulties.

Connections and selections: Comparing multivariate predictions and parameter associations from latent variable models of picture naming

Connectionist simulation models and processing tree mathematical models of picture naming have complementary advantages and disadvantages. These model types were compared in terms of their predictions of independent language measures and their associations between model components and measures that should be related according to their theoretical interpretations. The models were tasked with predicting independent picture naming data, neuropsychological test scores of semantic association and speech production, grammatical categories of formal errors, and lexical properties of target items. In all cases, the processing tree model parameters provided better predictions and stronger associations between parameters and independent language measures than the connectionist simulation model. Given the enhanced generalizability of latent variable measurements afforded by the processing tree model, evidence regarding mechanistic and representational features of the speech production system are re-evaluated. Several areas are indicated as being potentially viable targets for elaboration of the mechanistic descriptions of picture naming errors.

The Role of Word Properties in Performance on Fluency Tasks in People with Primary Progressive Aphasia

People with primary progressive aphasia (PPA) present language difficulties that require lengthy assessments and follow-ups. Despite individual differences, people with PPA are often classified into three variants that present some distinctive language difficulties. We analyzed the data of 6 fluency tasks (i.e., "F", "A", "S", "Fruits", "Animals", "Vegetables"). We used random forests to pinpoint relevant word properties and error types in the classification of the three PPA variants, conditional inference trees to indicate how relevant variables may interact with one another and ANOVAs to cross-validate the results. Results indicate that total word count helps distinguish healthy individuals (N = 10) from people with PPA (N = 29). Furthermore, mean familiarity differentiates people with svPPA (N = 8) from people with lvPPA (N = 10) and nfvPPA (N = 11). No other word property or error type was relevant in the classification. These results relate to previous literature, as familiarity effects have been reported in people with svPPA in naming and spontaneous speech. Also, they strengthen the relevance of using familiarity to identify a specific group of people with PPA. This paper enhances our understanding of what determines word retrieval in people with PPA, complementing and extending data from naming studies.

What Drives Task Performance During Animal Fluency in People With Alzheimer's Disease?

Background

Animal fluency is a widely used task to assess people with Alzheimer’s disease (AD) and other neurological disorders. The mechanisms that drive performance in this task are argued to rely on language and executive functions. However, there is little information regarding what specific aspects of these cognitive processes drive performance on this task.

Objective

To understand which aspects of language (i.e., semantics, phonological output lexicon, phonological assembly) and executive function (i.e., mental set shifting; information updating and monitoring; inhibition of possible responses) are involved in the performance of animal fluency in people with AD.

Methods

Animal fluency data from 58 people with probable AD from the DementiaBank Pittsburgh Corpus were analyzed. Number of clusters and switches were measured and nine word properties (e.g., frequency, familiarity) for each of the correct words (i.e., each word counting toward the total score, disregarding non-animals and repetitions) were determined. Random forests were used to understand which variables predicted the total number of correct words, and conditional inference trees were used to search for interactions between the variables. Finally, Wilcoxon tests were implemented to cross-validate the results, by comparing the performance of participants with scores below the norm in animal fluency against participants with scores within the norm based on a large normative sample.

Results

Switches and age of acquisition emerged as the most important variables to predict total number of correct words in animal fluency in people with AD. Cross-validating the results, people with AD whose animal fluency scores fell below the norm produced fewer switches and words with lower age of acquisition than people with AD with scores in the normal range.

Conclusion

The results indicate that people with AD rely on executive functioning (information updating and monitoring) and language (phonological output lexicon, not necessarily semantics) to produce words on animal fluency.

Abstract Semantic Associative Network Training: A Replication and Update of an Abstract Word Retrieval Therapy Program

Purpose We report on a study that replicates previous treatment studies using Abstract Semantic Associative Network Training (AbSANT), which was developed to help persons with aphasia improve their ability to retrieve abstract words, as well as thematically related concrete words. We hypothesized that previous results would be replicated; that is, when abstract words are trained using this protocol, improvement would be observed for both abstract and concrete words in the same context-category, but when concrete words are trained, no improvement for abstract words would be observed. We then frame the results of this study with the results of previous studies that used AbSANT to provide better evidence for the utility of this therapeutic technique. We also discuss proposed mechanisms of AbSANT. Method Four persons with aphasia completed one phase of concrete word training and one phase of abstract word training using the AbSANT protocol. Effect sizes were calculated for each word type for each phase. Effect sizes for this study are compared with the effect sizes from previous studies. Results As predicted, training abstract words resulted in both direct training and generalization effects, whereas training concrete words resulted in only direct training effects. The reported results are consistent across studies. Furthermore, when the data are compared across studies, there is a distinct pattern of the added benefit of training abstract words using AbSANT. Conclusion Treatment for word retrieval in aphasia is most often aimed at concrete words, despite the usefulness and pervasiveness of abstract words in everyday conversation. We show the utility of AbSANT as a means of improving not only abstract word retrieval but also concrete word retrieval and hope this evidence will help foster its application in clinical practice.

The verb and noun test for peri-operative testing (VAN-POP): standardized language tests for navigated transcranial magnetic stimulation and direct electrical stimulation

Background

Protocols for intraoperative language mapping with direct electrical stimulation (DES) often include various language tasks triggering both nouns and verbs in sentences. Such protocols are not readily available for navigated transcranial magnetic stimulation (nTMS), where only single word object naming is generally used. Here, we present the development, norming, and standardization of the verb and noun test for peri-operative testing (VAN-POP) that measures language skills more extensively.

Methods

The VAN-POP tests noun and verb retrieval in sentence context. Items are marked and balanced for several linguistic factors known to influence word retrieval. The VAN-POP was administered in English, German, and Dutch under conditions that are used for nTMS and DES paradigms. For each language, 30 speakers were tested.

Results

At least 50 items per task per language were named fluently and reached a high naming agreement.

Conclusion

The protocol proved to be suitable for pre- and intraoperative language mapping with nTMS and DES.

Mapping eloquent cortex: A voxel-based lesion-symptom mapping study of core speech production capacities in brain tumour patients

This study used voxel-based lesion-symptom mapping to examine the cortical and white matter regions associated with language production impairments in a sample of 63 preoperative tumour patients. We identified four cognitive functions considered crucial for spoken language production: semantic-to-lexical mapping (selecting the appropriate lexical label for the intended concept); phonological encoding (retrieving the word's phonological form); articulatory-motor planning (programming the articulatory motor movements); and goal-driven language selection (exerting top-down control over the words selected for production). Each participant received a score estimating their competence on each function. We then mapped the region(s) where pathology was significantly associated with low scores. For semantic-to-lexical mapping, the critical map encompassed portions of the left posterior middle and inferior temporal gyri, extending into posterior fusiform gyrus, overlapping substantially with the territory of the inferior longitudinal fasciculus. For phonological encoding, the map encompassed the left inferior parietal lobe and posterior middle temporal gyrus, overlapping with the territory of the inferior longitudinal and posterior arcuate fasciculi. For articulatory-motor planning, the map encompassed parts of the left frontal pole, frontal operculum, and inferior frontal gyrus, and overlapped with the territory of the frontal aslant tract. Finally, the map for goal-driven language selection encompassed the left frontal pole and the anterior cingulate cortex. We compare our findings with those from other neuropsychological samples, and conclude that the study of tumour patients offers evidence that complements that available from other populations.

Mapping psycholinguistic features to the neuropsychological and lesion profiles in aphasia

Naming and word retrieval deficits are two of the most persistent symptoms in chronic post-stroke aphasia. Naming success or failure on specific words can sometimes be predicted by the psycholinguistic properties of the word. Despite a wealth of literature investigating the influence of psycholinguistic properties in neuro-typical and clinical language processing, the underlying structure of these properties and their relation to the fundamental language components and neural correlates are unexplored. In this study, a multivariate data-decomposition approach was used to identify the underlying structure within a collection of psycholinguistic properties (word imageability, frequency, age-of-acquisition, familiarity, length, semantic diversity and phonological neighbourhood density) and their influence on naming accuracy was explored in a cohort of 42 participants with a diverse range of chronic post-stroke aphasia classifications and severities. The results extracted three principal psycholinguistic factors, which were best described as 'lexical usage', 'semantic clarity' and 'phonological complexity'. Furthermore, a novel approach was used to systematically relate the influence of these psycholinguistic properties to participants' neuropsychological and lesion profiles. The findings did not show a one-to-one mapping between psycholinguistic features and core language components. 'Lexical usage' was the only factor that showed a significant difference between fluent versus non-fluent aphasia groups in terms of the influence of this lexical factor on successful naming, and it was the only factor that was related to the pattern of patients' brain lesions. Voxel-wise whole brain lesion-symptom mapping identified left frontal regions, aligning with previous evidence that these regions are related to language production functions, including word retrieval and repetition. The evidence from the current study suggests that the functional locus of psycholinguistic properties is distributed across multiple language components rather than being localised to a single language element.

Can gesture observation help people with aphasia name actions?

It has been suggested that gesture can play a role in the treatment of naming impairments in aphasia, however investigation is still sparse, especially when compared to research on verbal treatments. Critically, previous studies have included either verbal or gesture production in the training. However, while in speakers without language impairment, action naming is facilitated by gesture observation, no study has yet systematically determined whether gesture observation alone influences word retrieval in people with aphasia. This is the aim of the research presented here. In a gesture priming experiment, participants with aphasia named actions that were preceded by the observation of videos of congruent or unrelated gestures or a non-gesture control condition. At the group-level, action naming was facilitated by observation of congruent gestures. However, single-case analyses revealed variability in the extent to which the participants benefited from gesture cueing. The potential mechanisms underlying the effects of gesture observation on action picture naming in people with aphasia were examined by exploring participant-related and item-related predictors of improvement. It is concluded that gesture observation may facilitate verb retrieval at either semantic or lexical levels. In addition, and despite variability across individuals, gesture observation seems more likely to facilitate action naming in people with spared gesture semantics and mild-moderate deficits in lexical-semantic or post-semantic processing.

Effects of semantic neighbourhood density on spoken word production

When producing words, it is generally agreed that semantically related words are activated along with the target. However, relatively little is known about the extent to which the number of such semantically related words affects the production of spoken words. The research presented here explores, in detail, the influence of semantic neighbourhood density—the number of words of similar meaning in the lexicon—on picture naming performance in both unimpaired speakers and a large group of individuals with aphasia. In Experiment 1, six different semantic neighbourhood density measures were compared using principal component analysis. Four different semantic neighbourhood density components were identified: feature-based, context-based, association-based, and distant. In Experiment 2, these new measures were used as predictors in an analysis of picture naming data from unimpaired English speakers: no significant effects of semantic neighbourhood factors were observed on either latency or accuracy. Finally, Experiment 3 reports an analysis of picture naming responses of a large group of individuals with aphasia ( n = 193), examining the influence of the semantic neighbourhood density measures. Effects of the feature-based semantic neighbourhood measure on accuracy varied across participants with no overall main effect. This same measure increased the probability of a coordinate error compared with a correct response but also compared with an omission. Results are best accommodated by theories of word production that incorporate mechanisms by which semantically related concepts can both facilitate and inhibit target production.

Continuous theta burst stimulation over right pars triangularis facilitates naming abilities in chronic post-stroke aphasia by enhancing phonological access

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been used experimentally to facilitate naming abilities in individuals with chronic post-stroke aphasia. However, little is known about how rTMS confers clinical improvement, hampering its therapeutic value. The present study investigated the characteristics of naming failure that improve following administration of continuous theta burst stimulation (cTBS)-an inhibitory form of rTMS-to the right pars triangularis (rPTr) in persons with chronic aphasia.

METHODS

Eleven participants with chronic aphasia following left hemisphere stroke named pictures prior to and immediately following cTBS of the rPTr and a control site (vertex) in separate sessions. Prior to stimulation, we obtained two baseline measurements of picture naming ability to determine the extent and type (i.e., phonological vs. semantic) of naming impairment. Items presented for naming during stimulation were those that were named incorrectly in one or both of the baseline sessions (i.e., inconsistent vs. wrong items, respectively). Analyses assessed whether cTBS effects differed depending on the severity and/or type of naming impairment.

RESULTS

Relative to vertex, cTBS of the rPTr improved naming of inconsistent, but not wrong, items for individuals with more severe baseline naming impairment. Critically, baseline phonological but not semantic naming impairment severity marginally correlated with improved accuracy overall, and significantly correlated with decreased phonological errors following rPTr stimulation.

CONCLUSION

CTBS of the rPTr enhances naming by facilitating phonological access during word retrieval, indicating that individuals whose naming impairment is localized to this stage of processing may be most likely to benefit from this rTMS approach.

The Subjective Experience of Inner Speech in Aphasia Is a Meaningful Reflection of Lexical Retrieval

Purpose Individuals with aphasia often report that they feel able to say words in their heads, regardless of speech output ability. Here, we examine whether these subjective reports of successful "inner speech" (IS) are meaningful and test the hypothesis that they reflect lexical retrieval. Method Participants were 53 individuals with chronic aphasia. During silent picture naming, participants reported whether or not they could say the name of each item inside their heads. Using the same items, they also completed 3 picture-based tasks that required phonological retrieval and 3 matched auditory tasks that did not. We compared participants' performance on these tasks for items they reported being able to say internally versus those they reported being unable to say internally. Then, we examined the relationship of psycholinguistic word features to self-reported IS and spoken naming accuracy. Results Twenty-six participants reported successful IS on nearly all items, so they could not be included in the item-level analyses. These individuals performed correspondingly better than the remaining participants on tasks requiring phonological retrieval, but not on most other language measures. In the remaining group ( n = 27), IS reports related item-wise to performance on tasks requiring phonological retrieval, but not to matched control tasks. Additionally, IS reports were related to 3 word characteristics associated with lexical retrieval, but not to articulatory complexity; spoken naming accuracy related to all 4 word characteristics. Six participants demonstrated evidence of unreliable IS reporting; compared with the group, they also detected fewer errors in their spoken responses and showed more severe language impairments overall. Conclusions Self-reported IS is meaningful in many individuals with aphasia and reflects lexical phonological retrieval. These findings have potential implications for treatment planning in aphasia and for our understanding of IS in the general population.

A cognitive psychometric model for assessment of picture naming abilities in aphasia

Picture naming impairments are a typical feature of stroke-induced aphasia. Overall accuracy and rates of different error types are used to make inferences about the severity and nature of damage to the brain's language network. Currently available assessment tools for picture naming accuracy treat it as a unidimensional measure, while assessment tools for error types treat items homogenously, contrary to findings from psycholinguistic investigations of word production. We created and tested a new cognitive psychometric model for assessment of picture naming responses, using cognitive theory to specify latent processing decisions during the production of a naming attempt, and using item response theory to separate the effects of item difficulty and participant ability on these internal processing decisions. The model enables multidimensional assessment of latent picture naming abilities on a common scale, with a relatively large cohort for normative reference. We present the results of 4 experiments testing our interpretation of the model's parameters, as they apply to picture naming predictions, lexical properties of the items, statistical properties of the lexicon, and participants' scores on other tests. We also created a website for researchers and clinicians to analyze item-level data using our model, providing estimates of latent abilities and percentile scores, as well as credible intervals to help gauge the reliability of the estimated model parameters and identify meaningful changes. To the extent that the model is successful, the estimated parameter values may aid in treatment decisions and progress monitoring, or they may help elucidate the functional properties of brain networks. (PsycINFO Database Record

Subjective age-of-acquisition norms for 600 Turkish words from four age groups

The main purpose of this study was to report age-based subjective age-of-acquisition (AoA) norms for 600 Turkish words. A total of 115 children, 100 young adults, 115 middle-aged adults, and 127 older adults provided AoA estimates for 600 words on a 7-point scale. The intraclass correlations suggested high reliability, and the AoA estimates were highly correlated across the four age groups. Children gave earlier AoA estimates than the three adult groups; this was true for high-frequency as well as low-frequency words. In addition to the means and standard deviations of the AoA estimates, we report word frequency, concreteness, and imageability ratings, as well as word length measures (numbers of syllables and letters), for the 600 words as supplemental materials. The present ratings represent a potentially useful database for researchers working on lexical processing as well as other aspects of cognitive processing, such as autobiographical memory.

Comparison of animal, action and phonemic fluency in aphasia

BACKGROUND

The ability to generate words that follow certain constraints, or verbal fluency, is a sensitive indicator of neurocognitive impairment, and is impacted by a variety of variables.

AIMS

To investigate the effect of post-stroke aphasia, elicitation category and linguistic variables on verbal fluency performance.

METHODS & PROCEDURES

Twenty-eight persons with aphasia (PWA) with a single left-hemisphere lesion and 40 age-matched neurotypical community-dwelling adults were administered three verbal fluency tasks: two semantic (animals and actions) and one phonemic (the letters F, A and S). Data analysis included comparison of total scores, clusters and perseverations. Individual responses were coded for frequency of occurrence, age of acquisition and syllable length to investigate qualitative differences in word generation.

OUTCOMES & RESULTS

PWA performed worse than neurotypical participants across all verbal fluency tasks, and animal fluency scores were farthest from neurotypical performance. PWAs' animal and action fluency were correlated with other language measures, while phonemic fluency was uncorrelated with language measures. While some PWAs showed dissociations between verbal fluency tasks, the dissociations did not pattern along with aphasia fluency. PWAs produced fewer clusters and responses with higher word frequency across all three verbal fluency tasks. Responses had earlier age of acquisition and shorter word length for animal and phonemic fluency, but not action fluency.

CONCLUSIONS & IMPLICATIONS

Verbal fluency, particularly animal fluency, is sensitive to even mild aphasia. PWA produced lexically simpler responses than their neurotypical peers. This study identifies the relevance of qualitative analysis of verbal fluency responses.

Exploring Treatment Fidelity in Persons With Aphasia Autonomously Practicing With Computerized Therapy Materials

PURPOSE

Current computer technologies permit independent practice for people with cognitive-communicative disorders. Previous research has investigated compliance rates and outcome changes but not treatment fidelity per se during practice. Our aim was to examine adherence to procedures (treatment fidelity) and accuracy while persons with aphasia independently practiced word production using interactive, multimodal, user-controlled, word-level icons on computers.

METHOD

Four persons with aphasia independently practiced single-word production after stimulation via user-initiated interactions in 3 conditions: (I) auditory stimulus with static representational drawing; (II) auditory stimulus with synchronized articulation video; and (III) users' choice between the 2 prior conditions. Sessions were video-recorded for subsequent analysis, which established emergently refined behavioral taxonomies using an iterative, mixed-methods approach.

RESULTS

In independent practice, users only sometimes adhere to modeled behaviors, other times improvising novel behaviors. The latter sometimes co-occurred with successful productions. Differences in success rates were noted between Conditions I and II across behaviors with Condition II generally favored. In Condition III, participants tended to choose the stimulus that resulted in highest success rates.

CONCLUSIONS

During independent practice with technology, persons with aphasia do not necessarily comply with clinicians' practice instructions, and treatment fidelity does not determine success. Autonomy and choice in practice may reveal unanticipated dimensions for computerized aphasia treatment.

Noun and verb processing in aphasia: Behavioural profiles and neural correlates

The behavioural and neural processes underpinning different word classes, particularly nouns and verbs, have been a long-standing area of interest in psycholinguistic, neuropsychology and aphasiology research. This topic has theoretical implications concerning the organisation of the language system, as well as clinical consequences related to the management of patients with language deficits. Research findings, however, have diverged widely, which might, in part, reflect methodological differences, particularly related to controlling the psycholinguistic variations between nouns and verbs. The first aim of this study, therefore, was to develop a set of neuropsychological tests that assessed single-word production and comprehension with a matched set of nouns and verbs. Secondly, the behavioural profiles and neural correlates of noun and verb processing were explored, based on these novel tests, in a relatively large cohort of 48 patients with chronic post-stroke aphasia. A data-driven approach, principal component analysis (PCA), was also used to determine how noun and verb production and comprehension were related to the patients' underlying fundamental language domains. The results revealed no performance differences between noun and verb production and comprehension once matched on multiple psycholinguistic features including, most critically, imageability. Interestingly, the noun-verb differences found in previous studies were replicated in this study once un-matched materials were used. Lesion-symptom mapping revealed overlapping neural correlates of noun and verb processing along left temporal and parietal regions. These findings support the view that the neural representation of noun and verb processing at single-word level are jointly-supported by distributed cortical regions. The PCA generated five fundamental language and cognitive components of aphasia: phonological production, phonological recognition, semantics, fluency, and executive function. Consistent with the behavioural analyses and lesion-symptom mapping results, both noun and verb processing loaded on common underlying language domains: phonological production and semantics. The neural correlates of these five principal components aligned with existing models of language and the regions implicated by other techniques such as functional neuroimaging and neuro-stimulation.

Age of acquisition for naming and knowing: A new hypothesis

This paper reports an investigation into the age of acquisition of object names and object knowledge in a cross-sectional study of 288 children aged between 3 years 7 months and 11 years 6 months, comprising equal numbers of boys and girls. The objects belonged to four categories: animals, fruit and vegetables, implements, and vehicles. They were presented in three image types: line drawings, black-and-white photographs, and coloured photographs. In the knowledge test, five probe questions were asked for each object given the spoken name. Results showed that line drawings were more difficult to name than either black-and-white photographs or coloured photographs, which did not differ. The boys significantly out-performed the girls at naming and knowing, both overall and specifically for the category of vehicles. Naming and knowledge increased steadily with age but while young children below about 6 years 6 months showed an advantage to naming, older children showed an advantage to knowing. Similarly, age-of-acquisition measures for each item revealed a significant shift in the relationship between naming and knowing at around 80 months. We argue that differences in learning experience lead younger and older children to associate object names with different types of information, and we suggest that this difference probably accounts for the age-of-acquisition effects reported in adult object naming.

The behavioural patterns and neural correlates of concrete and abstract verb processing in aphasia: A novel verb semantic battery

Typically, processing is more accurate and efficient for concrete than abstract concepts in both healthy adults and individuals with aphasia. While, concreteness effects have been thoroughly documented with respect to noun processing, other words classes have received little attention despite tending to be less concrete than nouns. The aim of the current study was to explore concrete-abstract differences in verbs and identify their neural correlates in post-stroke aphasia. Given the dearth of comprehension tests for verbs, a battery of neuropsychological tests was developed in this study to assess the comprehension of concrete and abstract verbs. Specifically, a sensitive verb synonym judgment test was generated that varied both the items' imageability and frequency, and a picture-to-word matching test with numerous concrete verbs. Normative data were then collected and the tests were administered to a cohort of 48 individuals with chronic post-stroke aphasia to explore the behavioural patterns and neural correlates of verb processing. The results revealed significantly better comprehension of concrete than abstract verbs, aligning with the existing aphasiological literature on noun processing. In addition, the patients performed better during verb comprehension than verb production. Lesion-symptom correlational analyses revealed common areas that support processing of concrete and abstract verbs, including the left anterior temporal lobe, posterior supramarginal gyrus and superior lateral occipital cortex. A direct contrast between them revealed additional regions with graded differences. Specifically, the left frontal regions were associated with processing abstract verbs; whereas, the left posterior temporal and occipital regions were associated with processing concrete verbs. Moreover, overlapping and distinct neural correlates were identified in association with the comprehension and production of concrete verbs. These patient findings align with data from functional neuroimaging and neuro-stimulation, and existing models of language organisation.

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Developed new verb comprehension tests

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Processing of concrete verbs is more accurate than abstract verbs in aphasia

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Neural correlates of semantic verb processing distributed in left cortical regions

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Graded neural difference between processing concrete and abstract verbs

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Graded neural differences observed in production and comprehension modalities

Effects of Lexical Variables on Silent Reading Comprehension in Individuals With Aphasia: Evidence From Eye Tracking

PURPOSE

Previous eye-tracking research has suggested that individuals with aphasia (IWA) do not assign syntactic structure on their first pass through a sentence during silent reading comprehension. The purpose of the present study was to investigate the time course with which lexical variables affect silent reading comprehension in IWA. Three lexical variables were investigated: word frequency, word class, and word length.

METHODS

IWA and control participants without brain damage participated in the experiment. Participants read sentences while a camera tracked their eye movements.

RESULTS

IWA showed effects of word class, word length, and word frequency that were similar to or greater than those observed in controls.

CONCLUSIONS

IWA showed sensitivity to lexical variables on the first pass through the sentence. The results are consistent with the view that IWA focus on lexical access on their first pass through a sentence and then work to build syntactic structure on subsequent passes. In addition, IWA showed very long rereading times and low skipping rates overall, which may contribute to some of the group differences in reading comprehension.

A selective morpho-phonological deficit?

We report on an English-speaking, aphasic individual (TB) who showed a striking dissociation in speaking with the different forms (allomorphs) that an inflection can take. Although very accurate in producing the consonantal inflections (-/s/, -/z/, -/d/, -/t/), TB consistently omitted syllabic inflections (-/əz/, -/əd/), therefore correctly saying "dogs" or "walked," but "bench" for benches or "skate" for skated. Results from control tests ruled out that TB's selective difficulties stemmed from problems in selecting the correct inflection for the syntactic context or problems related to phonological or articulatory mechanisms. TB's selective difficulties appeared instead to concern morpho-phonological mechanisms responsible for adapting morphological elements to word phonology. These mechanisms determine whether the plural inflection surfaces in the noun bench as voiced (-/z/), unvoiced (-/s/) or syllabic (-/əz/). Our results have implications for understanding how morphological elements are encoded in the lexicon and the nature of morpho-phonological mechanisms involved in speech production.

Objective support for subjective reports of successful inner speech in two people with aphasia

People with aphasia frequently report being able to say a word correctly in their heads, even if they are unable to say that word aloud. It is difficult to know what is meant by these reports of "successful inner speech". We probe the experience of successful inner speech in two people with aphasia. We show that these reports are associated with correct overt speech and phonologically related nonword errors, that they relate to word characteristics associated with ease of lexical access but not ease of production, and that they predict whether or not individual words are relearned during anomia treatment. These findings suggest that reports of successful inner speech are meaningful and may be useful to study self-monitoring in aphasia, to better understand anomia, and to predict treatment outcomes. Ultimately, the study of inner speech in people with aphasia could provide critical insights that inform our understanding of normal language.

Russian normative data for 375 action pictures and verbs

The present article introduces a Russian-language database of 375 action pictures and associated verbs with normative data. The pictures were normed for name agreement, conceptual familiarity, and subjective visual complexity, and measures of age of acquisition, imageability, and image agreement were collected for the verbs. Values of objective visual complexity, as well as information about verb frequency, length, argument structure, instrumentality, and name relation, are also provided. Correlations between these parameters are presented, along with a comparative analysis of the Russian name agreement norms and those collected in other languages. The full set of pictorial stimuli and the obtained norms may be freely downloaded from http://neuroling.ru/en/db.htm for use in research and for clinical purposes.

Aphasia in Persian: Implications for cognitive models of lexical processing

Current models of oral reading assume that different routes (sublexical, lexical, and semantic) mediate oral reading performance and reliance on different routes during oral reading depends on the characteristics of print to sound mappings. Studies of single cases of acquired dyslexia in aphasia have contributed to the development of such models by revealing patterns of double dissociation in object naming and oral reading skill that follow brain damage in Indo-European and Sino-Tibetan languages. Print to sound mapping in Persian varies in transparency because orthography to phonology translation depends uniquely on the presence or absence of vowel letters in print. Here a hypothesis is tested that oral reading in Persian requires a semantic reading pathway that is independent of a direct non-semantic reading pathway, by investigating whether Persian speakers with aphasia show selective impairments to object naming and reading aloud. A sample of 21 Persian speakers with aphasia ranging in age from 18 to 77 (mean = 53, SD = 16.9) was asked to name a same set of 200 objects and to read aloud the printed names of these objects in different sessions. As an additional measure of sublexical reading, patients were asked to read aloud 30 non-word stimuli. Results showed that oral reading is significantly more preserved than object naming in Persian speakers with aphasia. However, more preserved object naming than oral reading was also observed in some cases. There was a moderate positive correlation between picture naming and oral reading success (p < .05). Mixed-effects logistic regression revealed that word frequency, age of acquisition and imageability predict success across both tasks and there is an interaction between these variables and orthographic transparency in oral reading. Furthermore, opaque words were read less accurately than transparent words. The results reveal different patterns of acquired dyslexia in some cases that closely resemble phonological, deep, and surface dyslexia in other scripts - reported here in Persian for the first time.

Taking Sides: An Integrative Review of the Impact of Laterality and Polarity on Efficacy of Therapeutic Transcranial Direct Current Stimulation for Anomia in Chronic Poststroke Aphasia

Anomia is a frequent and persistent symptom of poststroke aphasia, resulting from damage to areas of the brain involved in language production. Cortical neuroplasticity plays a significant role in language recovery following stroke and can be facilitated by behavioral speech and language therapy. Recent research suggests that complementing therapy with neurostimulation techniques may enhance functional gains, even amongst those with chronic aphasia. The current review focuses on the use of transcranial Direct Current Stimulation (tDCS) as an adjunct to naming therapy for individuals with chronic poststroke aphasia. Our survey of the literature indicates that combining therapy with anodal (excitatory) stimulation to the left hemisphere and/or cathodal (inhibitory) stimulation to the right hemisphere can increase both naming accuracy and speed when compared to the effects of therapy alone. However, the benefits of tDCS as a complement to therapy have not been yet systematically investigated with respect to site and polarity of stimulation. Recommendations for future research to help determine optimal protocols for combined therapy and tDCS are outlined.