Maximiliano A. Wilson

The role of the left anterior temporal lobe in exception word reading: reconciling patient and neuroimaging findings.

Semantic dementia (SD) is a neurodegenerative disease that occurs following the atrophy of the anterior temporal lobes (ATLs). It is characterised by the degradation of semantic knowledge and difficulties in reading exception words (surface dyslexia). This disease has highlighted the role of the ATLs in the process of exception word reading. However, imaging studies in healthy subjects have failed to detect activation of the ATLs during exception word reading. The aim of the present study was to test whether the functional brain regions that mediate exception word reading in normal readers overlap those brain regions atrophied in SD. In Study One, we map the brain regions of grey matter atrophy in AF, a patient with mild SD and surface dyslexia profile. In Study Two, we map the activation pattern associated with exception word compared to pseudoword reading in young, healthy participants using fMRI. The results revealed areas of significant activation in healthy subjects engaged in the exception word reading task in the left anterior middle temporal gyrus, in a region observed to be atrophic in the patient AF. These results reconcile neuropsychological and functional imaging data, revealing the critical role of the left ATL in exception word reading.

Impaired L1 and executive control after left basal ganglia damage in a bilingual Basque-Spanish person with aphasia

Bilinguals must focus their attention to control competing languages. In bilingual aphasia, damage to the fronto-subcortical loop may lead to pathological language switching and mixing and the attrition of the more automatic language (usually L1). We present the case of JZ, a bilingual Basque–Spanish 53-year-old man who, after haematoma in the left basal ganglia, presented with executive deficits and aphasia, characterised by more impaired language processing in Basque, his L1. Assessment with the Bilingual Aphasia Test revealed impaired spontaneous and automatic speech production and speech rate in L1, as well as impaired L2-to-L1 sentence translation. Later observation led to the assessment of verbal and non-verbal executive control, which allowed JZs impaired performance on language tasks to be related to executive dysfunction. In line with previous research, we report the significant attrition of L1 following damage to the left basal ganglia, reported for the first time in a Basque–Spanish bilingual. Implications for models of declarative and procedural memory are discussed.

Revisiting age-of-acquisition effects in Spanish visual word recognition: the role of item imageability.

Word age-of-acquisition (AoA) affects reading. The mapping hypothesis predicts AoA effects when input-output mappings are arbitrary. In Spanish, the orthography-to-phonology mappings required for word naming are consistent; therefore, no AoA effects are expected. Nevertheless, AoA effects have been found, motivating the present investigation of how AoA can affect reading in Spanish. Four experiments were run to examine reading with a factorial design manipulating AoA and frequency. In Experiments 1 and 2 (immediate and speeded naming), only word frequency affected word naming. In Experiment 3 (lexical decision), both AoA and frequency affected word recognition. In Experiment 4 (immediate naming with highly imageable items), both frequency and AoA affected naming. The results suggest that highly imageable items induce a larger reliance on semantics in reading aloud. Such reliance causes faster naming of earlier acquired words because the corresponding concepts have richer visual and sensory features acquired mainly through direct sensory experience.

Norms for name agreement, familiarity, subjective frequency, and imageability for 348 object names in Tunisian Arabic.

Normative databases for pictorial stimuli are widely used in research on language processing in order to control for a number of psycholinguistic variables in the selected stimuli. Such resources are lacking for Arabic and its dialectal varieties. In the present study, we aimed to provide Tunisian Arabic (TA) normative data for 348 line drawings taken from Cycowicz, Friedman, Rothstein, and Snodgrass (1997), which include Snodgrass and Vanderwart’s (1980) 260 pictures. Norms were collected for the following psycholinguistic variables: name agreement, familiarity, subjective frequency, and imageability. Word length data (in numbers of phonemes and syllables) are also listed in the database. We investigated the effects of these variables on word reading in TA. We found that word length and frequency were the best predictors of word-reading latencies in TA. Name agreement was also a significant predictor of word-reading latencies. A particularly interesting finding was that the semantic variables, imageability and familiarity, affected word-reading latencies in TA. Thus, it would seem that TA readers rely on semantics even when reading individual Arabic words that are transparent in terms of orthography-to-phonology mappings. This database represents a precious and much-needed psycholinguistic resource for researchers investigating language processing in Arabic-speaking populations.

Semantic Dementia without Surface Dyslexia in Spanish: Unimpaired Reading with Impaired Semantics

Surface dyslexia has been attributed to an overreliance on the sub-lexical route for reading. Typically, surface dyslexic patients commit regularisation errors when reading irregular words. Also, semantic dementia has often been associated with surface dyslexia, leading to some explanations of the reading impairment that stress the role of semantics in irregular word reading. Nevertheless, some patients have been reported with unimpaired ability to read irregular words, even though they show severe comprehension impairment. We present the case of M.B., the first Spanish-speaking semantic dementia patient to be reported who shows unimpaired reading of non-words, regular words, and–most strikingly–irregular loan words. M.B. has severely impaired comprehension of the same words he reads correctly (whether regular or irregular). We argue that M.B.’s pattern of performance shows that irregular words can be correctly read even with impaired semantic knowledge corresponding to those words.

Bilingual lexical selection as a dynamic process:evidence from Arabic-French bilinguals

The nature of the lexical selection process in bilingual spoken word production is one of the pending questions of research on bilingualism. According to one view this competitive process is language-specific, while another holds that it is language-nonspecific (i.e., lexical competition is cross-linguistic). In recent years, research on bilingual language production has seen the rise of a third view that postulates that lexical selection is in fact dynamic and may function as language-specific or nonspecific depending on a number of factors. The aim of the present study was to investigate the lexical selection process among moderately proficient bilinguals whose two languages are typologically distant: Tunisian Arabic and French. The picture-word interference task was used in two experiments where moderately proficient Tunisian Arabic (L1)-French (L2) bilinguals were asked to name pictures in their L2 while ignoring auditory distractors (semantic, phono-translation, phonological, or unrelated) in their L2 (Experiment 1) or their L1 (Experiment 2). Thus, the language context was entirely monolingual in Experiment 1 and bilingual in Experiment 2. In Experiment 1, only a phonological facilitation effect was observed. In Experiment 2, interference was found in the phono-translation, semantic, and phonological conditions. Taken together, these results indicate that cross-language competition occurs among moderately proficient Tunisian Arabic-French bilinguals only in a bilingual context (Experiment 2) as indexed by the phono-translation interference effect observed. Our findings are in line with the recent hypothesis that lexical selection is a dynamic process modulated by factors like language similarity, language proficiency, and the experimental language context.

Naming unique entities in the semantic variant of primary progressive aphasia and Alzheimer's disease: Towards a better understanding of the semantic impairment

ABSTRACT While the semantic variant of primary progressive aphasia (svPPA) is characterized by a predominant semantic memory impairment, episodic memory impairments are the clinical hallmark of Alzheimers disease (AD). However, AD patients also present with semantic deficits, which are more severe for semantically unique entities (e.g. a famous person) than for common concepts (e.g. a beaver). Previous studies in these patient populations have largely focused on famous‐person naming. Therefore, we aimed to evaluate if these impairments also extend to other semantically unique entities such as famous places and famous logos. In this study, 13 AD patients, 9 svPPA patients, and 12 cognitively unimpaired elderly subjects (CTRL) were tested with a picture‐naming test of non‐unique entities (Boston Naming Test) and three experimental tests of semantically unique entities assessing naming of famous persons, places, and logos. Both clinical groups were overall more impaired at naming semantically unique entities than non‐unique entities. Naming impairments in AD and svPPA extended to the other types of semantically unique entities, since a CTRL>AD>svPPA pattern was found on the performance of all naming tests. Naming famous places and famous persons appeared to be most impaired in svPPA, and both specific and general semantic knowledge for these entities were affected in these patients. Although AD patients were most significantly impaired on famous‐person naming, only their specific semantic knowledge was impaired, while general knowledge was preserved. Post‐hoc neuroimaging analyses also showed that famous‐person naming impairments in AD correlated with atrophy in the temporo‐parietal junction, a region functionally associated with lexical access. In line with previous studies, svPPA patients’ impairment in both naming and semantic knowledge suggest a more profound semantic impairment, while naming impairments in AD may arise to a greater extent from impaired lexical access, even though semantic impairment for specific knowledge is also present. These results highlight the critical importance of developing and using a variety of semantically‐unique‐entity naming tests in neuropsychological assessments of patients with neurodegenerative diseases, which may unveil different patterns of lexical‐semantic deficits. HIGHLIGHTSFamous‐person naming was specifically impaired in AD patients.Both famous‐person and ‐place naming were specifically impaired in svPPA patients.General and specific semantic knowledge was impaired in svPPA, but general knowledge was preserved in AD.svPPA patients’ impairment in naming and knowledge suggest a profound semantic impairment.Naming impairments in AD may arise to a greater extent from impaired lexical access.

Reading in Spanish and Italian: effects of age of acquisition in transparent orthographies?

Despite the similar transparency of their orthographies, reading in Italian has been found to be affected by frequency but not age of acquisition (AoA) [Barca, L., Burani, C., & Arduino, L. S. (2002). Word naming times and psycholinguistic norms for Italian nouns. Behaviour Research Methods, Instruments and Computers, 34, 424–434] while reading in Spanish is affected by AoA but not frequency [Cuetos, F., & Barbón, A. (2006). Word naming in Spanish. European Journal of Cognitive Psychology, 18, 415–436]. We examined this cross-linguistic difference, firstly, through a reanalysis of the Italian and Spanish reading latencies. After eliminating several between-experiment differences, we replicated the AoA effect in Spanish but not in Italian and the frequency effect in Italian but not in Spanish. The cross-linguistic comparison could not equate stimulus imageability; therefore, secondly, we compared the Italian reading latencies with new Spanish reading latencies for imageability-matched words. We found frequency effects but neither an AoA effect nor a language by AoA interaction. We argue that the previously reported cross-linguistic difference in the AoA effect resulted from a between-study difference in stimulus imageability. More imageable words induced more semantic involvement in reading, yielding an AoA effect in Spanish.

Lexical decision with pseudohomophones and reading in the semantic variant of primary progressive aphasia: A double dissociation

The co-occurrence of semantic impairment and surface dyslexia in the semantic variant of primary progressive aphasia (svPPA) has often been taken as supporting evidence for the central role of semantics in visual word processing. According to connectionist models, semantic access is needed to accurately read irregular words. They also postulate that reliance on semantics is necessary to perform the lexical decision task under certain circumstances (for example, when the stimulus list comprises pseudohomophones). In the present study, we report two svPPA cases: M.F. who presented with surface dyslexia but performed accurately on the lexical decision task with pseudohomophones, and R.L. who showed no surface dyslexia but performed below the normal range on the lexical decision task with pseudohomophones. This double dissociation between reading and lexical decision with pseudohomophones is in line with the dual-route cascaded (DRC) model of reading. According to this model, impairments in visual word processing in svPPA are not necessarily associated with the semantic deficits characterizing this disease. Our findings also call into question the central role given to semantics in visual word processing within the connectionist account.

TDQ-60 – a color picture-naming test for adults and elderly people: validation and normalization data

ABSTRACT Word-finding difficulties are usually assessed with picture-naming tests. In this article, we present the TDQ-60, a new test designed to assess acquired lexical access deficits, taking into account semantics and psycholinguistic variables. The article includes three studies. Study 1 describes the development phase of the TDQ-60. In study 2, healthy control participants and individuals with a diagnosis of the semantic variant of primary progressive aphasia were assessed to establish the convergent and discriminant validity of the TDQ-60. Finally, in Study 3, a group of 305 young and elderly French-speaking adults from Quebec were assessed in order to provide normative data. The results demonstrate that the TDQ-60 has good convergent validity and good discriminant validity. This study also provides normative data in which were considered the effect of age and education.The TDQ-60 is a new valid picture-naming test, controlled for psycholinguistic variables and designed to identify the influence of semantics on lexical access in spoken production.