Visuo-Attentional and Phonological Deficits Explored in French Students with Dyslexia: Eye Movements Recorded during a Phonological Lexical Decision Task.

Whether dyslexia is caused by phonological or attentional dysfunction remains a widely debated issue. To enrich this debate, we compared the eye movements of 32 French university students with (14 students) and without (18 students) dyslexia while performing a delayed phonological lexical decision task on 300 visually presented stimuli. The processing stimuli involved either a lexical (i.e., words) or a non-lexical route relying on a grapheme-phoneme correspondence (pseudohomophones and pseudowords), while other stimuli involved only a visual search (consonant and symbol sequences). We recorded the number of fixations, the duration of the first fixation and the amplitude of saccades made on the stimuli. Compared to the controls, the participants with dyslexia made more fixations while reading regardless of the type of stimulus (lexical and non-lexical). Crucially, the participants with dyslexia exhibited longer first fixations in particular while reading phonologically challenging stimuli such as pseudohomophones and pseudowords compared to stimuli involving a simple visual search (consonants, symbols). Taken together, these results suggest that both visual and phonological impairments may be implicated in dyslexia, supporting the hypothesis that dyslexia is a multifactorial deficit.

Processing of complex morphosyntactic structures in French: ERP evidence from native speakers.

This event-related brain potentials (ERP) study investigated the neurocognitive mechanisms underlying the auditory processing of verbal complexity in French illustrated by the prescriptive present subjunctive mode. Using a violation paradigm, ERPs of 32 French native speakers were continuously recorded while they listened to 200 ecological French sentences selected from the INTEFRA oral corpus (2006). Participants performed an offline acceptability judgement task on each sentence, half of which contained a correct present subjunctive verbal agreement (reçoive) and the other half an incorrect present indicative one (peut). Critically, the present subjunctive mode was triggered either by verbs (Ma mère desire que j'apprenneMy mother wants me to learn) or by subordinating conjunctions (Pour qu'elle reçoiveSo that she receives). We found a delayed anterior negativity (AN) due to the length of the verbal forms and a P600 that were larger for incongruent than for congruent verbal agreement in the same time window. While the two effects were left lateralized for subordinating conjunctions, they were right lateralized for both structures with a larger effect for subordinating conjunctions than for verbs. Moreover, our data revealed that the AN/P600 pattern was larger in late position than in early ones. Taken together, these results suggest that morphosyntactic complexity conveyed by the French subjunctive involves at least two neurocognitive processes thought to support an initial morphosyntactic analysis (AN) and a syntactic revision and repair (posterior P600). These two processes may be modulated as a function of both the element (i.e., subordinating conjunction vs verb) that triggers the subjunctive mode and the moment at which this element is used while sentence processing.

The Subjunctive as a Model of Grammatical Complexity: An Integrative Review of Issues Based on Combined Evidence from Mental Chronometry and Neurosciences.

The acquisition of a second language requires the construction or reconstruction of linguistic knowledge about the new language system. Learners of a second language have to acquire the linguistic structures of the second language by constructing or reassessing their own knowledge in the light of the new one. Some of these new linguistic structures may be more or less complex to process and/or difficult to acquire. In this review, we focus on an example of linguistic complexity in French, namely, the subjunctive. Through a discussion of some selected studies on the second language acquisition of the French subjunctive, our purpose is to argue that these findings, considered from a psycholinguistic perspective, could be fruitful for further research employing neuroscience techniques, such as electroencephalography or neuroimaging in order to better understand the neurocognitive processing of this complex structure both in French native speakers and in learners of French. Hence, we aim to contribute to exploring the question of linguistic transfer in the field of second language acquisition, the typological distance/relation between L1-L2, the syntactic acquisition of complex structures in adult second language learners, and the potential contributions of electroencephalography and functional magnetic resonance imaging to the processing of the subjunctive, selected as an example of linguistic complexity that has not yet received much attention.

Evidence from ERP and Eye Movements as Markers of Language Dysfunction in Dyslexia.

Developmental dyslexia is a complex reading disorder involving genetic and environmental factors. After more than a century of research, its etiology remains debated. Two hypotheses are often put forward by scholars to account for the causes of dyslexia. The most common one, the linguistic hypothesis, postulates that dyslexia is due to poor phonological awareness. The alternative hypothesis considers that dyslexia is caused by visual-attentional deficits and abnormal eye movement patterns. This article reviews a series of selected event-related brain potential (ERP) and eye movement studies on the reading ability of dyslexic individuals to provide an informed state of knowledge on the etiology of dyslexia. Our purpose is to show that the two abovementioned hypotheses are not necessarily mutually exclusive, and that dyslexia should rather be considered as a multifactorial deficit.

Manual and Spoken Cues in French Sign Language's Lexical Access: Evidence From Mouthing in a Sign-Picture Priming Paradigm.

Although Sign Languages are gestural languages, the fact remains that some linguistic information can also be conveyed by spoken components as mouthing. Mouthing usually tend to reproduce the more relevant phonetic part of the equivalent spoken word matching with the manual sign. Therefore, one crucial issue in sign language is to understand whether mouthing is part of the signs themselves or not, and to which extent it contributes to the construction of signs meaning. Another question is to know whether mouthing patterns constitute a phonological or a semantic cue in the lexical sign entry. This study aimed to investigate the role of mouthing on the processing of lexical signs in French Sign Language (LSF), according the type of bilingualism (intramodal vs. bimodal). For this purpose, a behavioral sign-picture lexical decision experiment was designed. Intramodal signers (native deaf adults) and Bimodal signers (fluent hearing adults) have to decide as fast as possible whether a picture matched with the sign seen just before. Five experimental conditions in which the pair sign-mouthing were congruent or incongruent were created. Our results showed a strong interference effect when the sign-mouthing matching was incongruent, reflected by higher error rates and lengthened reaction times compared with the congruent condition. This finding suggests that both groups of signers use the available lexical information contained in mouthing during accessing the sign meaning. In addition, deaf intramodal signers were strongly interfered than hearing bimodal signers. Taken together, our data indicate that mouthing is a determining factor in LSF lexical access, specifically in deaf signers.

Neuroplasticity in the phonological system: The PMN and the N400 as markers for the perception of non-native phonemic contrasts by late second language learners.

Second language (L2) learners frequently encounter persistent difficulty in perceiving certain non-native sound contrasts, i.e., a phenomenon called "phonological deafness". However, if extensive L2 experience leads to neuroplastic changes in the phonological system, then the capacity to discriminate non-native phonemic contrasts should progressively improve. Such perceptual changes should be attested by modifications at the neurophysiological level. We designed an EEG experiment in which the listeners' perceptual capacities to discriminate second language phonemic contrasts influence the processing of lexical-semantic violations. Semantic congruency of critical words in a sentence context was driven by a phonemic contrast that was unique to the L2, English (e.g.,/ɪ/-/i:/, ship - sheep). Twenty-eight young adult native speakers of French with intermediate proficiency in English listened to sentences that contained either a semantically congruent or incongruent critical word (e.g., The anchor of theship/*sheepwas let down) while EEG was recorded. Three ERP effects were found to relate to increasing L2 proficiency: (1) a left frontal auditory N100 effect, (2) a smaller fronto-central phonological mismatch negativity (PMN) effect and (3) a semantic N400 effect. No effect of proficiency was found on oscillatory markers. The current findings suggest that neuronal plasticity in the human brain allows for the late acquisition of even hard-wired linguistic features such as the discrimination of phonemic contrasts in a second language. This is the first time that behavioral and neurophysiological evidence for the critical role of neural plasticity underlying L2 phonological processing and its interdependence with semantic processing has been provided. Our data strongly support the idea that pieces of information from different levels of linguistic processing (e.g., phonological, semantic) strongly interact and influence each other during online language processing.

Language experience in LSF development: Behavioral evidence from a sentence repetition task.

In psycholinguistics and clinical linguistics, the Sentence Repetition Task (SRT) is known to be a valuable tool to screen general language abilities in both spoken and signed languages. This task enables users to reliably and quickly assess linguistic abilities at different levels of linguistic analysis such as phonology, morphology, lexicon, and syntax. To evaluate sign language proficiency in deaf children using French Sign Language (LSF), we designed a new SRT comprising 20 LSF sentences. The task was administered to a cohort of 62 children- 34 native signers (6;09-12 years) and 28 non-native signers (6;08-12;08 years)-in order to study their general linguistic development as a function of age of sign language acquisition (AOA) and chronological age (CA). Previously, a group of 10 adult native signers was also evaluated with this task. As expected, our results showed a significant effect of AOA, indicating that the native signers repeated more signs and were more accurate than non-native signers. A similar pattern of results was found for CA. Furthermore, native signers made fewer phonological errors (i.e., handshape, movement, and location) than non-native signers. Finally, as shown in previous sign language studies, handshape and movement proved to be the most difficult parameters to master regardless of AOA and CA. Taken together, our findings support the assumption that AOA is a crucial factor in the development of phonological skills regardless of language modality (spoken vs. signed). This study thus constitutes a first step toward a theoretical description of the developmental trajectory in LSF, a hitherto understudied language.

A review on the electroencephalography markers of Stroop executive control processes.

The present article on executive control addresses the issue of the locus of the Stroop effect by examining neurophysiological components marking conflict monitoring, interference suppression, and conflict resolution. Our goal was to provide an overview of a series of determining neurophysiological findings including neural source reconstruction data on distinct executive control processes and sub-processes involved in the Stroop task. Consistently, a fronto-central N2 component is found to reflect conflict monitoring processes, with its main neural generator being the anterior cingulate cortex (ACC). Then, for cognitive control tasks that involve a linguistic component like the Stroop task, the N2 is followed by a centro-posterior N400 and subsequently a late sustained potential (LSP). The N400 is mainly generated by the ACC and the prefrontal cortex (PFC) and is thought to reflect interference suppression, whereas the LSP plausibly reflects conflict resolution processes. The present overview shows that ERP constitute a reliable methodological tool for tracing with precision the time course of different executive processes and sub-processes involved in experimental tasks involving a cognitive conflict. Future research should shed light on the fine-grained mechanisms of control respectively involved in linguistic and non-linguistic tasks.

Impairment in Attention Focus During the Posner Cognitive Task in Children With ADHD: An Eye Tracker Study.

Attention is a major cognitive function that allows the individuals to focus selectively on a discrete stimulus while ignoring others. Visual information could be driven endogenously, when the goals or desires are voluntary, or exogenously, in response to salient visual events in the environment. Since subjects with attention deficit hyperactivity disorder (ADHD) show heightened distractibility during activities that require significant attentional engagement, we hypothesized that they may be more severely impaired in their ability to perform endogenous tasks than controls. To elicit endogenous and exogenous shifts of attention, we thus used a modified version of Posner's cueing task. We compared oculomotor performance measured by an eye tracker in a group of 31 children with ADHD (mean age = 9.1 ± 1.3 years) and age-, sex-, and IQ-matched typically developing children. Endogenous and exogenous conditions were explored in three distinct visual sub-conditions (valid, invalid, and neutral). We found that children with ADHD showed longer latency during endogenous conditions compared to TD children in invalid sub-conditions. They also performed more errors than controls, during the endogenous task in neutral sub-conditions and during exogenous task in neutral and invalid sub-conditions. Our study suggests that children with ADHD may allocate their attention resource toward the detection of exogenous targets with a deficit in their ability to perform endogenous task. We suggest also that they have a difficulty in the engagement of the inhibitory control system particularly during voluntary saccade performance. This could result from impaired interactions between the ventral and dorsal attention networks as well as in the frontal eye field, although neuroimaging studies are necessary to validate this hypothesis in the ADHD population.

Perception of lexical neutral tones in mandarin compounds: Electroencephalographic evidence from an oddball paradigm.

The present electroencephalographic (EEG) study was designed to investigate the perception of Mandarin neutral tone (T0) by adult Mandarin speakers. For this purpose, we examined the event-related brain potential (ERP) correlates of T0 processing in two-character Mandarin compounds. Eighteen native Mandarin speakers were tested using a modified oddball paradigm. Sixty strong-strong and 60 strong-weak (T0) disyllabic Mandarin compounds were selected from the Contemporary Chinese Dictionary. Participants performed one explicit task of stress discrimination (i.e., deciding whether the fourth word in sequences of 4 spoken words had the same stress pattern as the previous words or a different one) and one implicit task of passive listening. Behaviorally, accuracy showed that Mandarin listeners were able to correctly discriminate T0 from the canonical strong-strong stress pattern in 87.2% of cases. Neurophysiologically, larger N200 and P200 were observed for the infrequent strong-weak stress pattern compared to the canonical strong-strong one. Critically, a N325 was replicated in Mandarin, with a larger N325 for strong-weak than for strong-strong compounds. Consistently with a previous interpretation proposed by Böcker et al. (1999) for Dutch, we argue that the N325 might be a manifestation of the extraction of stress pattern in Mandarin also. Taken together, the present data on T0 perception in Mandarin are discussed in the context of the Prosody-Assisted-Processing (PAP) model (Isel et al., 2003), a cognitive model of spoken compound processing based on stress-timed languages, which postulates an early involvement of prosody in order to guide the morphological analysis at the lexical level.

Neurophysiological differentiation between preattentive and attentive processing of emotional expressions on French vowels.

The present electrophysiological study investigated the processing of emotional prosody by minimizing as much as possible the effect of emotional information conveyed by the lexical-semantic context. Emotionally colored French vowels (i.e., happiness, sadness, fear, and neutral) were presented in a mismatch negativity (MMN) oddball paradigm. Both the MMN, i.e., an event-related potential (ERP) component thought to reflect preattentive change detection, and the P3a, i.e., an ERP marker of involuntary orientation of attention toward deviant stimuli, were significantly modulated by the emotional deviants compared to the neutral ones. Critically, the largest amplitude (MMN, P3a) and the shortest peak latency (MMN) were observed for fear deviants, all other things being equal. Taken together, the present findings lend support to a sequential neurocognitive model of emotion processing (Scherer, 2001) which postulates, among other checks, a first stage of automatic emotion detection (MMN) followed by a second stage of subjective evaluation of the stimulus or event (P3a). Consistently with previous studies, our data suggest that among the six universal emotions, fear could have a special status probably because of its adaptive role in the evolution of the human species.

Inhibition Efficiency in Highly Proficient Bilinguals and Simultaneous Interpreters: Evidence from Language Switching and Stroop Tasks.

The present behavioral study aimed to examine the impact of language control expertise on two domain-general control processes, i.e. active inhibition of competing representations and overcoming of inhibition. We compared how Simultaneous Interpreters (SI) and Highly Proficient Bilinguals-two groups assumed to differ in language control capacity-performed executive tasks involving specific inhibition processes. In Experiment 1 (language decision task), both active and overcoming of inhibition processes are involved, while in Experiment 2 (bilingual Stroop task) only interference suppression is supposed to be required. The results of Experiment 1 showed a language switching effect only for the highly proficient bilinguals, potentially because overcoming of inhibition requires more cognitive resources than in SI. Nevertheless, both groups performed similarly on the Stroop task in Experiment 2, which suggests that active inhibition may work similarly in both groups. These contrasting results suggest that overcoming of inhibition may be harder to master than active inhibition. Taken together, these data indicate that some executive control processes may be less sensitive to the degree of expertise in bilingual language control than others. Our findings lend support to psycholinguistic models of bilingualism postulating a higher-order mechanism regulating language activation.

Multiple Language Use Influences Oculomotor Task Performance: Neurophysiological Evidence of a Shared Substrate between Language and Motor Control.

In the present electroencephalographical study, we asked to which extent executive control processes are shared by both the language and motor domain. The rationale was to examine whether executive control processes whose efficiency is reinforced by the frequent use of a second language can lead to a benefit in the control of eye movements, i.e. a non-linguistic activity. For this purpose, we administrated to 19 highly proficient late French-German bilingual participants and to a control group of 20 French monolingual participants an antisaccade task, i.e. a specific motor task involving control. In this task, an automatic saccade has to be suppressed while a voluntary eye movement in the opposite direction has to be carried out. Here, our main hypothesis is that an advantage in the antisaccade task should be observed in the bilinguals if some properties of the control processes are shared between linguistic and motor domains. ERP data revealed clear differences between bilinguals and monolinguals. Critically, we showed an increased N2 effect size in bilinguals, thought to reflect better efficiency to monitor conflict, combined with reduced effect sizes on markers reflecting inhibitory control, i.e. cue-locked positivity, the target-locked P3 and the saccade-locked presaccadic positivity (PSP). Moreover, effective connectivity analyses (dynamic causal modelling; DCM) on the neuronal source level indicated that bilinguals rely more strongly on ACC-driven control while monolinguals rely on PFC-driven control. Taken together, our combined ERP and effective connectivity findings may reflect a dynamic interplay between strengthened conflict monitoring, associated with subsequently more efficient inhibition in bilinguals. Finally, L2 proficiency and immersion experience constitute relevant factors of the language background that predict efficiency of inhibition. To conclude, the present study provided ERP and effective connectivity evidence for domain-general executive control involvement in handling multiple language use, leading to a control advantage in bilingualism.

Functional significance of the semantic P600: evidence from the event-related brain potential source localization.

Previous event-related potentials studies of sentence comprehension have usually associated syntactic repair/reanalysis processes with the P600 component. However, the functional significance of the P600 was recently questioned on the basis of the observation of P600 effects in response to the processing of semantically anomalous sentences. In the present study, we investigated the functional significance of the 'semantic P600' using a semantic violation paradigm with a focus-on-syntax instruction. Using a source localization analysis, we tested three alternative hypotheses on the function of the P600: (i) a syntactic function, (ii) an executive function, and (iii) a semantic/integrational function. We assumed that distinct neuronal generators should reflect each of these functions. Although the syntactic generators are expected to be mainly located in the left inferior frontal gyrus, the semantic generators should be observed in the left superior temporal gyrus as well as in the right anterior prefrontal cortex (semantic retrieval); moreover, the generator of executive function (conflict monitoring) should be found in the anterior cingulate cortex. Critically, we defined a dipole model using 17 dipoles, 14 of which were placed in the three regions of interest corresponding to our hypotheses, namely, syntactic, executive, and semantic regions. Our data showed that the P600 effect was significant in the anterior cingulate cortex and marginally significant in the right anterior prefrontal cortex. This finding suggests that the P600 might reflect more general mechanisms of conflict monitoring and semantic reinterpretation leading to a retrieval of world knowledge from long-term memory rather purely syntactic processes.

Neurodynamics of executive control processes in bilinguals: evidence from ERP and source reconstruction analyses.

The present study was designed to examine the impact of bilingualism on the neuronal activity in different executive control processes namely conflict monitoring, control implementation (i.e., interference suppression and conflict resolution) and overcoming of inhibition. Twenty-two highly proficient but non-balanced successive French-German bilingual adults and 22 monolingual adults performed a combined Stroop/Negative priming task while event-related potential (ERP) were recorded online. The data revealed that the ERP effects were reduced in bilinguals in comparison to monolinguals but only in the Stroop task and limited to the N400 and the sustained fronto-central negative-going potential time windows. This result suggests that bilingualism may impact the process of control implementation rather than the process of conflict monitoring (N200). Critically, our study revealed a differential time course of the involvement of the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC) in conflict processing. While the ACC showed major activation in the early time windows (N200 and N400) but not in the latest time window (late sustained negative-going potential), the PFC became unilaterally active in the left hemisphere in the N400 and the late sustained negative-going potential time windows. Taken together, the present electroencephalography data lend support to a cascading neurophysiological model of executive control processes, in which ACC and PFC may play a determining role.

Effect of language task demands on the neural response during lexical access: a functional magnetic resonance imaging study.

This study examined the effects of linguistic task demands on the neuroanatomical localization of the neural response related to automatic semantic processing of concrete German nouns combining the associative priming paradigm with functional magnetic resonance imaging (fMRI). To clarify the functional role of the inferior frontal gyrus (IFG) for semantic processing with respect to semantic decision making compared to semantic processing per se, we used a linguistic task that involved either a binary decision process (i.e., semantic categorization; Experiment 1) or not (i.e., silently thinking about a word's meaning; Experiment 2). We observed associative priming effects indicated as neural suppression in bilateral superior temporal gyri (STG), anterior cingulate cortex (ACC), occipito-temporal brain areas, and in medial frontal brain areas independently of the linguistic task. Inferior parietal brain areas were more active for silently thinking about a word's meaning compared to semantic categorization. A conjunction analysis of linguistic task revealed that both tasks activated the same left-lateralized occipito-temporo-frontal network including the IFG. Contrasting neural associative priming effects across linguistic task demands, we found a significant interaction in the right IFG. The present fMRI data give rise to the assumption that activation of the left inferior frontal gyrus (LIFG) in the semantic domain might be important for semantic processing in general and not only for semantic decision making. These findings contrast with a recent study regarding the role of the LIFG for binary decision making in the lexical domain (Wright et al. 2011).

Modulation of semantic integration as a function of syntactic expectations: event-related brain potential evidence.

This study investigated syntax-semantics interactions during spoken sentence comprehension. We showed that expectations of phrase-structure incongruencies, which were induced by the experimental instructions, although not actually present in the sentences, were able to block the process of semantic integration. Although this process is usually associated with an N400 event-related brain potential component, here we found a P600, that is, an event-related brain potential component that is thought to reflect syntactic revision. This finding lends support to neurophysiological models of sentence interpretation, which postulates that the lexical-semantic integration of a given word can take place only when syntactic analysis has been successfully completed.

Neural circuitry of the bilingual mental lexicon: effect of age of second language acquisition.

Numerous studies have proposed that changes of the human language faculty caused by neural maturation can explain the substantial differences in ultimate attainment of grammatical competences between first language (L1) acquirers and second language (L2) learners. However, little evidence on the effect of neural maturation on the attainment of lexical knowledge in L2 is available. The present functional magnetic resonance study addresses this question via a cross-linguistic neural adaptation paradigm. Age of acquisition (AoA) of L2 was systematically manipulated. Concrete nouns were repeated across language (e.g., French-German, valise(suitcase)-Koffer(suitcase)). Whereas early bilinguals (AoA of L2<3years) showed larger repetition enhancement (RE) effects in the left superior temporal gyrus, the bilateral superior frontal gyrus and the right posterior insula, late bilinguals (AoA of L2>10years) showed larger RE effects in the middle portion of the left insula and in the right middle frontal gyrus (MFG). We suggest that, as for grammatical knowledge, the attainment of lexical knowledge in L2 is affected by neural maturation. The present findings lend support to neurocognitive models of bilingual word recognition postulating that, for both early and late bilinguals, the two languages are interconnected at the conceptual level.

Syntactic and referential processes in second-language learners: event-related brain potential evidence.

Automatic phrase-building processes were investigated in second-language (L2) learners of French (native German speakers). Event-related brain potentials were recorded while participants listened to syntactically or semantically correct or incorrect French sentences containing a subject-modifying relative clause. Phrase structure violations in the subject-modifying relative clause leading to difficulties in reference processing of the subject noun in the main clause (syntactic condition) were associated with a frontal negativity (150-600 ms) followed by a late anterior negativity (750-1500 ms). Violations of the selectional restriction (semantic condition) elicited the classical N400 (300-600 ms). Taken together, our results suggest that automatic syntactic phrase-building processes can also be involved in L2 learners, at least when the word category violation occurs in a syntactically obligatory constituent such as predicative prepositional phrase.