Inferring native language from early bio-electrical activity

Analysis of postures for handwriting on touch screens without using tools

The act of handwriting affected the evolutionary development of humans and still impacts the motor cognition of individuals. However, the ubiquitous use of digital technologies has drastically decreased the number of times we really need to pick a pen up and write on paper. Nonetheless, the positive cognitive impact of handwriting is widely recognized, and a possible way to merge the benefits of handwriting and digital writing is to use suitable tools to write over touchscreens or graphics tablets. In this manuscript, we focus on the possibility of using the hand itself as a writing tool. A novel hand posture named FingerPen is introduced, and can be seen as a grasp performed by the hand on the index finger. A comparison with the most common posture that people tend to assume (i.e. index finger-only exploitation) is carried out by means of a biomechanical model. A conducted user study shows that the FingerPen is appreciated by users and leads to accurate writing traits.

Broca Pars Triangularis Constitutes a "Hub" of the Language-Control Network during Simultaneous Language Translation

Until now, several branches of research have fundamentally contributed to a better understanding of the ramifications of bilingualism, multilingualism, and language expertise on psycholinguistic-, cognitive-, and neural implications. In this context, it is noteworthy to mention that from a cognitive perspective, there is a strong convergence of data pointing to an influence of multilingual speech competence on a variety of cognitive functions, including attention, short-term- and working memory, set shifting, switching, and inhibition. In addition, complementary neuroimaging findings have highlighted a specific set of cortical and subcortical brain regions which fundamentally contribute to administrate cognitive control in the multilingual brain, namely Broca's area, the middle-anterior cingulate cortex, the inferior parietal lobe, and the basal ganglia. However, a disadvantage of focusing on group analyses is that this procedure only enables an approximation of the neural networks shared within a population while at the same time smoothing inter-individual differences. In order to address both commonalities (i.e., within group analyses) and inter-individual variability (i.e., single-subject analyses) in language control mechanisms, here I measured five professional simultaneous interpreters while the participants overtly translated or repeated sentences with a simple subject-verb-object structure. Results demonstrated that pars triangularis was commonly activated across participants during backward translation (i.e., from L2 to L1), whereas the other brain regions of the "control network" showed a strong inter-individual variability during both backward and forward (i.e., from L1 to L2) translation. Thus, I propose that pars triangularis plays a crucial role within the language-control network and behaves as a fundamental processing entity supporting simultaneous language translation.

How do bilinguals identify the language of the words they read?

How do bilinguals detect the language of the words they read? Recent electrophysiological research using the masked priming paradigm combining primes and targets from different languages has shown that bilingual readers identify the language of the words within approximately 200 ms. Recent evidence shows that language-detection mechanisms vary as a function of the orthographic markedness of the words (i.e., whether or not a given word contains graphemic combinations that are not legal in the other language). The present study examined how the sub-lexical orthographic regularities of words are used as predictive cues. Spanish-Basque bilinguals and Spanish monolinguals (control group) were tested in an Event-Related Potential (ERP) experiment, using the masked priming paradigm. During the experiment, Spanish targets were briefly preceded by unrelated Spanish or Basque words. Unrelated Basque words could contain bigram combinations that are either plausible or implausible in the target language (Spanish). Results show a language switch effect in the N250 and N400 components for marked Basque primes in both groups, whereas, in the case of unmarked Basque primes, language switch effects were found in bilinguals but not monolinguals. These data demonstrate that statistical orthographic regularities of words play an important role in bilingual language detection, and provide new evidence supporting the assumptions of the BIA+ extended model.

Electrophysiological explorations of the bilingual advantage: evidence from a Stroop task

Bilinguals have been shown to exhibit a performance advantage on executive control tasks, outperforming their monolingual counterparts. Although a wealth of research has investigated this 'bilingual advantage' behaviourally, electrophysiological correlates are lacking. Using EEG with a Stroop task that manipulated the stimulus onset asynchrony (SOA) of word and colour presentation, the current study addressed two facets of the bilingual advantage. The possibility that bilinguals experience superior conflict processing relative to monolinguals (a 'conflict-specific advantage') was investigated by comparing behavioural interference effects as well as the amplitude of the Ninc, a conflict-related ERP component occurring from approximately 300-500 ms after the onset of conflict. In contrast, the hypothesis that bilinguals experience domain-general, conflict-independent enhancements in executive processing (a 'non-conflict-specific advantage') was evaluated by comparing the control condition (symbol strings) between groups. There was some significant, but inconsistent, evidence for a conflict-specific bilingual advantage. In contrast, strong evidence emerged for a non-conflict-specific advantage, with bilinguals demonstrating faster RTs and reduced ERP amplitudes on control trials compared to monolinguals. Importantly, when the control stimulus was presented before the colour, ERPs to control trials revealed group differences before the onset of conflict, suggesting differences in the ability to ignore or suppress distracting irrelevant information. This indicates that bilinguals experience superior executive processing even in the absence of conflict and semantic salience, and suggests that the advantage extends to more efficient proactive management of the environment.

The timing and magnitude of Stroop interference and facilitation in monolinguals and bilinguals

Executive control abilities and lexical access speed in Stroop performance were investigated in English monolinguals and two groups of bilinguals (English-Chinese and Chinese-English) in their first (L1) and second (L2) languages. Predictions were based on a bilingual cognitive advantage hypothesis, implicating cognitive control ability as the critical factor determining Stroop interference; and two bilingual lexical disadvantage hypotheses, focusing on lexical access speed. Importantly, each hypothesis predicts different response patterns in a Stroop task manipulating stimulus onset asynchrony (SOA). There was evidence for a bilingual cognitive advantage, although this effect was sensitive to a number of variables including proficiency, language immersion, and script. In lexical access speed, no differences occurred between monolinguals and bilinguals in their native languages, but there was evidence for a delay in L2 processing speed relative to the L1. Overall, the data highlight the multitude of factors affecting executive control and lexical access speed in bilinguals.

The Investigation of Simultaneous Interpreters as an Alternative Approach to Address the Signature of Multilingual Speech Processing

In the field of cognitive neuroscience, understanding the functional, temporal, and anatomical characteristics of multilingual speech processing has previously been a topic of intense investigations. In this article, I will attempt to describe how the investigation of simultaneous interpreters can be used as a fruitful and alternative approach for better comprehending the neuronal signature of multilingual speech processing, foreign language acquisition, as well as the functional and structural adaptivity of the human brain in general. Thereby, I will primarily focus on the commonalities underlying different degrees of speech competence rather than on the differences. In this context, particular emphasis will be placed on the contribution of extra-linguistic brain functions which are necessary for accommodating cognitive and motor control mechanisms in the multilingual brain. Certainly, the framework outlined in this article will not replace the meanwhile established psycholinguistic or neuroscientific models of speech processing, but only attempts to provide a novel and alternative perspective.

Cognitive and electrophysiological correlates of the bilingual stroop effect

The color word Stroop effect in bilinguals is commonly half the magnitude when the written and naming languages are different (between) than when they are the same (within). This between-within language Stroop difference (BWLS) is likened to a response set effect, with greater response conflict for response relevant than irrelevant words. The nature of the BWLS was examined using a bilingual Stroop task. In a given block (Experiment 1), color congruent and incongruent words appeared in the naming language or not (single), or randomly in both languages (mixed). The BWLS effect was present for both balanced and unbalanced bilinguals, but only partially supported a response set explanation. As expected, color incongruent trials during single language blocks, lead to slower response times within than between languages. However, color congruent trials during mixed language blocks led to slower times between than within languages, indicating that response-irrelevant stimuli interfered with processing. In Experiment 2, to investigate the neural timing of the BWLS effect, event related potentials were recorded while balanced bilinguals named silently within and between languages. Replicating monolingual findings, an N450 effect was observed with larger negative amplitude for color incongruent than congruent trials (350-550 ms post-stimulus onset). This effect was equivalent within and between languages, indicating that color words from both languages created response conflict, contrary to a strict response set effect. A sustained negativity (SN) followed with larger amplitude for color incongruent than congruent trials, resolving earlier for between than within language Stroop. This effect shared timing (550-700 ms), but not morphology or scalp distribution with the commonly reported sustained potential. Finally, larger negative amplitude (200-350 ms) was observed between than within languages independent of color congruence. This negativity, likened to a no-go N2, may reflect processes of inhibitory control that facilitate the resolution of conflict at the SN, while the N450 reflects parallel processing of distracter words, independent of response set (or language). In sum, the BWLS reflects brain activity over time with contributions from language and color conflict at different points.

Intensive language training and attention modulate the involvement of fronto-parietal regions during a non-verbal auditory discrimination task

This event-related functional magnetic resonance imaging (fMRI) study was designed in such a manner so as to contribute to the present debate on behavioural and functional transfer effects associated with intensive language training. To address this novel issue, we measured professional simultaneous interpreters and control subjects while they performed a non-verbal auditory discrimination task that primarily relies on attention and categorization functions. The fMRI results revealed that the discrimination of the target stimuli was associated with differential blood oxygen level-dependent responses in fronto-parietal regions between the two groups, even though in-scanner behavioural results did not show significant group differences. These findings are in line with previous observations showing the contribution of fronto-parietal regions to auditory attention and categorization functions. Our results imply that language training modulates brain activity in regions involved in the top-down regulation of auditory functions.

Electrophysiological correlates of early processing of visual word recognition: N2 as an index of visual category feature processing

A fundamental question in second language learning is how the brain separates inputs from different languages into distinct representation systems prior to semantic activation. The present study investigated this question using a silent reading task in which Latin letters and simple Chinese characters (including real characters and pseudocharacters) appeared randomly for 100 milliseconds (ms). High-density event-related potentials were employed to record the electrophysiological correlates of visual word recognition prior to motor response. The results showed that real Chinese characters and pseudocharacters produced a larger N2 response than letters within 200-300ms time window. However, no significant differences between real Chinese characters and pseudocharacters were found. The separation of two languages into their own systems might occur in the time window when N2 was elicited. The segregation of real Chinese characters and pseudocharacters was observed in a later time window (350-450ms). The category feature processing of stimuli might be responsible for the N2 response; the processing allows stimuli of the same category to be analyzed in their specific units and distinguishes different stimuli.

New insights into name category-related effects: is the Age of Acquisition a possible factor?

BACKGROUND

Electrophysiological, hemodynamic and neuropsychological studies have provided evidence of dissociation in the way words belonging to different semantic categories (e.g., animals, tools, actions) are represented in the brain. The aim of the present study was to investigate whether a word's semantic domain may affect the amplitude and latency of ERP components, independently of any other factor.

METHODS

EEGs were recorded from 16 volunteers engaged in a lexical decision task (word/non-word discrimination) involving 100 words (flora and fauna names). This task allowed us to evaluate differences in processing between words belonging to different categories (fauna vs. flora) independently of task demands. All stimuli were balanced in terms of length, frequency of occurrence, familiarity and imageability. Low Resolution Electromagnetic Tomography (LORETA) was performed on ERP difference waves of interest.

RESULTS

Our findings showed that the two categories were discriminated as early as 200 ms post-stimulus, with larger responses to flora names over the left occipito-temporal areas, namely BA37 and BA20. Category-related ERP differences were also observed in the amplitudes of the later centro-parietal N400, posterior P300 and anterior LP components. Behavioral responses to words denoting fauna were more accurate than to words denoting flora.

CONCLUSION

Overall, it seems that it was easier to access the lexical properties of fauna, probably because of their biologically relevant status. The results are discussed in the light of the possible role played by different factors.

RP and N400 ERP components reflect semantic violations in visual processing of human actions

Event-related brain potentials (ERPs) were used to investigate the visual processing of actions belonging to the typical human repertoire. Two hundred and sixty coloured pictures representing persons differing in number, age and gender, engaged in simple actions, were presented to 23 right-handed students. Perception of meaningful actions (e.g., young woman trying shoes in shop) was contrasted with perception of actions lacking an understandable goal (e.g., businesswoman balancing on one foot in desert). The results indicated early recognition of comprehensible behaviour in the form of an enhanced posterior "recognition potential" (RP) (N250), which was followed by a larger negativity (N400) in response to incongruent actions. The results suggest that incoming visual information regarding human gestures is processed similarly to linguistic inputs from a conceptual point of view, thus eliciting a posterior RP when the action code is visually recognized and comprehended, and a later N400 when the action is not recognized or is difficult to integrate with previous knowledge.

Foreword to the special issue. "Before the N400: Early Latency Language ERPs"

As cognitive and neural models of language processing have developed, so have the ranks of language-related event-related potential (ERP) components. This special issue is intended to showcase current cutting-edge research on this topic, with an emphasis on those ERP components peaking earlier than the N400, and their implications for neurocognitive language models. Both reading and speech comprehension are addressed due to the close relationship between these two topics. As the contents of this special issue illustrate, the high temporal resolution of the ERP methodology makes it especially suitable for illuminating three fundamental questions about the language comprehension process: (1) How early is semantics? (2) In what order do these cognitive operations occur in? (3) To what extent are the cognitive operations serial and to what extent are they in parallel?

ERP measures of partial semantic knowledge: left temporal indices of skill differences and lexical quality

This study examines the sensitivity of early event-related potentials (ERPs) to degrees of word semantic knowledge. Participants with strong, average, or weak vocabulary skills made speeded lexical decisions to letter strings. To represent the full spectrum of word knowledge among adult native-English speakers, we used rare words that were orthographically matched with more familiar words and with pseudowords. Since the lexical decision could not reliably be made on the basis of word form, subjects were obliged to use semantic knowledge to perform the task. A d' analysis suggested that high-skilled subjects adopted a more conservative strategy in response to rare versus more familiar words. Moreover, the high-skilled participants showed a trend towards an enhanced "N2c" to rare words, and a similar posterior temporal effect reached significance approximately 650 ms. Generators for these effects were localized to left temporal cortex. We discuss implications of these results for word learning and for theories of lexical semantic access.