Brain responses to lexical attestedness and phonological well-formedness as revealed by fast periodic visual stimulation.

We investigated the mechanisms underlying the online-processing of phonological constraints using oddball fast-periodic visual stimulation coupled with EEG. We focused on the Sonority Sequencing Principle and examined whether steady-state visual evoked potentials (SSVEPs) are sensitive to the sonority constraint on syllable onsets. Native French speakers were presented with streams of CCVC non-words (C: consonant, V: vowel) at a fixed 6-Hz base rate. We manipulated the phonological well-formedness and lexical attestedness of CC onsets in two conditions. SSVPs were observed at the base rate associated to visual stimuli. As expected, they did not differ between conditions. Oddball SSVEPs were observed at 1.2 Hz (and its harmonics) and differed in the two conditions. These results showed that SSVEPs are sensitive to sublexical features. They also suggest that the processing of phonological constraints rely on mechanisms which could be dissociated from those underlying the processing of statistical properties of the lexicon.

Is heart rate variability biofeedback useful in children and adolescents? A systematic review.

BACKGROUND: Heart rate variability (HRV) is considered as an index of both physical and emotional health, and biofeedback aiming to increase the level of HRV has demonstrated extensive beneficial effects. Although HRV biofeedback is commonly and reliably applied in adults, the use of this technique, alone or in addition to other treatments, in children and adolescents has not been widely explored to date. METHODS: This systematic review following PRISMA guidelines covers all human studies using HRV biofeedback in children and adolescents. A literature search was conducted in PsycINFO, PubMed and Scopus, and a standardized methodological quality assessment was performed. RESULTS: Results showed the efficiency of HRV biofeedback sessions with children and adolescents to reduce physical and mental health-related symptoms and enhance well-being. CONCLUSIONS: These findings underline the therapeutic value of using HRV biofeedback as a complement to more conventional behavioural and cognitive interventions to help children to manage stress and/or pain. Capitalizing on the identified strengths and shortcomings of available results, we propose research avenues as well as evidence-based clinical guidelines for using HRV biofeedback in clinical paediatric settings.

Processing of numerical representation of fingers depends on their location in space.

Fingers can express quantities and thus contribute to the acquisition and manipulation of numbers as well as the development of arithmetical skills. As embodied entities, the processing of finger numerical configurations should, therefore, be facilitated when they match shared cultural representations and are presented close to the body. To investigate these issues, the present study investigated whether canonical finger configurations are processed faster than noncanonical configurations or spatially matched dot configurations, taking into account their location in the peripersonal or the extrapersonal space. Analysis of verbal responses to the enumeration of small and large numerosities showed that participants (N = 30) processed small numerosities faster than large ones and dots faster than finger configurations despite visuo-spatial matching. Canonical configurations were also processed faster than noncanonical configurations but for finger numerical stimuli only. Furthermore, the difference in response time between dots and fingers processing was greater when the stimuli were located in the peripersonal space than in the extrapersonal space. As a whole, the data suggest that, due to their motor nature, finger numerical configurations are not processed as simple visual stimuli but in relation to corporal and cultural counting habits, in agreement with the embodied framework of numerical cognition.

Assessing Mathematical School Readiness.

Early math skills matter for later formal mathematical performances, academic and professional success. Accordingly, it is important to accurately assess mathematical school readiness (MSR) at the beginning of elementary school. This would help identifying children who are at risk of encountering difficulties in math and then stimulate their acquisition of mathematical skills as soon as possible. In the present study, we present a new test that allows professionals working with children (e.g., teachers, school psychologists, speech therapists, and school doctors) to assess children's MSR when they enter formal schooling in a simple, rapid and efficient manner. 346 children were assessed at the beginning of 1st Grade (6-to-7-year-olds) with a collective test assessing early mathematical abilities (T1). In addition, children's math skills were evaluated with classical curriculum math tests at T1 and a year later, in 2nd Grade (T2, 7-to-8-year-olds). After assessing internal consistency, three tasks were retained for the final version of the MSR test. Test performance confirmed to be essentially unidimensional and systematically related to the scores children obtained in classical tests in 1st and 2nd Grade. By using the present MSR test, it is possible to identify pupils at risk of developing low math skills right from the start of formal schooling in 1st Grade. Such a tool is needed, as children's level in math at school beginning (or school readiness) is known to be foundational for their future academic and professional carrier.

A rapid, objective and implicit measure of visual quantity discrimination.

There is evidence that accurate and rapid judgments of visual quantities form an essential component of human mathematical ability. However, explicit behavioural discrimination measures of visual quantities are readily contaminated both by variations in low-level physical parameters and higher order cognitive factors, while implicit measures often lack objectivity and sensitivity at the individual participant level. Here, with electrophysiological frequency tagging, we show discrimination differences between briefly presented visual quantities as low as a ratio of 1.4 (i.e., 14 vs. 10 elements). From this threshold, the neural discrimination response increases with parametrically increasing differences in ratio between visual quantities. Inter-individual variability in magnitude of the EEG response at this population threshold ratio predicts behavioural performance at an independent number comparison task. Overall, these findings indicate that visual quantities are perceptually discriminated automatically and rapidly (i.e., at a glance) within the occipital cortex. Given its high sensitivity, this paradigm could provide an implicit diagnostic neural marker of this process suitable for a wide range of fundamental and clinical applications.

Early activation of Broca's area in grammar processing as revealed by the syntactic mismatch negativity and distributed source analysis.

Though activation of Broca's region in the combinatorial processing of symbols (language, music) has been revealed by neurometabolic studies, most previous neurophysiological research found the earliest grammar indices in the temporal cortex, with inferior-frontal generators becoming active at relatively late stages. We use the attention- and task-free syntactic mismatch negativity (sMMN) event-related potential (ERP) to measure rapid and automatic sensitivity of the human brain to grammatical information in participants' native language (French). Further, sources underlying the MMN were estimated by applying the Parametrical Empirical Bayesian (PEB) approach, with the Multiple Sparse Priors (MSP) technique. Results showed reliable grammar-related activation focused on Broca's region already in the 150-190 ms time window, providing robust documentation of its involvement in the first stages of syntactic processing.

Estimation abilities of large numerosities in Kindergartners.

The approximate number system (ANS) is thought to be a building block for the elaboration of formal mathematics. However, little is known about how this core system develops and if it can be influenced by external factors at a young age (before the child enters formal numeracy education). The purpose of this study was to examine numerical magnitude representations of 5-6 year old children at 2 different moments of Kindergarten considering children's early number competence as well as schools' socio-economic index (SEI). This study investigated estimation abilities of large numerosities using symbolic and non-symbolic output formats (8-64). In addition, we assessed symbolic and non-symbolic early number competence (1-12) at the end of the 2nd (N = 42) and the 3rd (N = 32) Kindergarten grade. By letting children freely produce estimates we observed surprising estimation abilities at a very young age (from 5 year on) extending far beyond children's symbolic explicit knowledge. Moreover, the time of testing has an impact on the ANS accuracy since 3rd Kindergarteners were more precise in both estimation tasks. Additionally, children who presented better exact symbolic knowledge were also those with the most refined ANS. However, this was true only for 3rd Kindergarteners who were a few months from receiving math instructions. In a similar vein, higher SEI positively impacted only the oldest children's estimation abilities whereas it played a role for exact early number competences already in 2nd and 3rd graders. Our results support the view that approximate numerical representations are linked to exact number competence in young children before the start of formal math education and might thus serve as building blocks for mathematical knowledge. Since this core number system was also sensitive to external components such as the SEI this implies that it can most probably be targeted and refined through specific educational strategies from preschool on.

Numerical and nonnumerical estimation in children with and without mathematical learning disabilities.

There are currently multiple explanations for mathematical learning disabilities (MLD). The present study focused on those assuming that MLD are due to a basic numerical deficit affecting the ability to represent and to manipulate number magnitude ( Butterworth, 1999 , 2005 ; A. J. Wilson & Dehaene, 2007 ) and/or to access that number magnitude representation from numerical symbols ( Rousselle & Noël, 2007 ). The present study provides an original contribution to this issue by testing MLD children (carefully selected on the basis of preserved abilities in other domains) on numerical estimation tasks with contrasting symbolic (Arabic numerals) and nonsymbolic (collection of dots) numbers used as input or output. MLD children performed consistently less accurately than control children on all the estimation tasks. However, MLD children were even weaker when the task involved the mapping between symbolic and nonsymbolic numbers than when the task required a mapping between two nonsymbolic numerical formats. Moreover, in the estimation of nonsymbolic numerosities, MLD children relied more than control children on perceptual cues such as the cumulative area of the dots. Finally, the task requiring a mapping from a nonsymbolic format to a symbolic format was the best predictor of MLD. In order to explain these present results, as well as those reported in the literature, we propose that the impoverished number magnitude representation of MLD children may arise from an initial mapping deficit between number symbols and that magnitude representation.

Symbolic and nonsymbolic number comparison in children with and without dyscalculia.

Developmental dyscalculia (DD) is a pervasive difficulty affecting number processing and arithmetic. It is encountered in around 6% of school-aged children. While previous studies have mainly focused on general cognitive functions, the present paper aims to further investigate the hypothesis of a specific numerical deficit in dyscalculia. The performance of 10- and 11-year-old children with DD characterised by a weakness in arithmetic facts retrieval and age-matched control children was compared on various number comparison tasks. Participants were asked to compare a quantity presented in either a symbolic (Arabic numerals, number words, canonical dots patterns) or a nonsymbolic format (noncanonical dots patterns, and random sticks patterns) to the reference quantity 5. DD children showed a greater numerical distance effect than control children, irrespective of the number format. This favours a deficit in the specialised cognitive system underlying the processing of number magnitude in children with DD. Results are discussed in terms of access and representation deficit hypotheses.

Effect of face familiarity on age decision.

The present experiment was planned to check whether the extraction of apparent age is affected by face identity (familiarity) or not. According to the traditional view, age estimation should be carried out independently of face identity, because it is one of the visually derived semantic codes (like gender and ethnicity). However, little is known about its underlying mechanisms. Moreover, some recent studies have cast doubt on the parallel thesis regarding facial expression, facial speech, ethnicity, and gender. Given the promising results of a pilot experiment (n=24), 16 Caucasian participants were enrolled in an "age decision" task on morphed faces derived from one old and one young source-face, in the proportion 70:30. The respondents had previously been familiarised with half the source faces by a learning procedure (associating the face, surname, occupation and city of residence of the person displayed), while the remaining half were unfamiliar. The results showed that age decision was affected by face familiarity, at least when the task was perceptually difficult enough. This adds support to the thesis that the identification of identity and the extraction of visually derived semantic codes are not made independently from each other. The status of age, within the visually derived semantic codes, is also discussed.