Are dates processed like words rather than like numbers? A study of transposition priming effects

Poster (2019, May)

Neuropsychological case-studies suggested that dates and encyclopedic numbers may be processed differently than unknown numbers. However, this issue was not yet investigated in reading in healthy ... [more ▼]

Neuropsychological case-studies suggested that dates and encyclopedic numbers may be processed differently than unknown numbers. However, this issue was not yet investigated in reading in healthy participants, so that it is unclear if dates are read like words and processed as lexical items, or like numbers where each position strictly defines the digit value in a base-10 system. Here, we compared processing of known dates to unknown numbers in a group of 26 experts (students and teachers in History). Participants performed an explicit recognition task on dates (e.g., 1789, 1945, …) and on acronyms (e.g., FNRS, HDMI, …), half known and half unknown. They were preceded by an identical prime (e.g., 1945-1945), a transposed-character prime (e.g., 1495-1945) or a substituted-character prime (e.g., 1635-1945). Results show that for dates, there is a significant transposition gain (-57ms), while for unknown numbers as well as for acronyms (known and unknown), the transposed-character prime induced a cost (from +17 to +257ms) rather than a gain. The facilitation due to transposed characters found here on dates is similar to what is observed in studies of lexical decision on words. Therefore, it suggests that dates may be processed with similar types of orthographical mechanisms than words. [less ▲]

Lateralization for faces in prereaders depends on the perceptual processing level: An EEG Fast Periodic Visual Stimulation study

Poster (2019, January)

The developmental origin of human adults’ right hemispheric lateralization to face stimuli is unclear, in particular because young infants’ right hemispheric advantage in face perception is no longer ... [more ▼]

The developmental origin of human adults’ right hemispheric lateralization to face stimuli is unclear, in particular because young infants’ right hemispheric advantage in face perception is no longer present in preschool children, before written language acquisition. Here we used fast periodic visual stimulation (FPVS) with scalp electrophysiology to test 52 preschool children (5 years old) at two levels of face processing (i.e., faces vs. objects, or discrimination between individual faces). While the contrast between faces and nonface objects elicits strictly bilateral occipital responses in children, discrimination of faces on the basis of identity in the same children is associated with a strong right hemispheric lateralization over the occipito-temporal cortex. Inversion of the face stimuli does not modulate right lateralization but significantly decreases the discrimination response. Furthermore, there is no relationship between right hemispheric lateralization in individual face discrimination and preschool levels of letter recognition. These observations suggest that right lateralization for face perception is essentially driven by the necessity to process faces at the level of identity. Overall, they also challenge the view that the adult right hemispheric lateralization for face perception emerges late and slowly during childhood due to increased competition with left lateralized posterior network for reading. [less ▲]

Spatial Skills First: The Importance of Mental Rotation for Arithmetic Skill Acquisition

in Journal of Numerical Cognition (2019)

The relation between visuospatial abilities and verbal number skills in preschool: Adding spatial language to the equation

Poster (2018, September)

Project NUMTEST: Assessing basic number competence without language

Poster (2018, June 28)

Although numerical skills are essential in modern societies, 5- 7 % of the population suffer from mathematical learning disabilities. Due to the hierarchical nature of mathematical knowledge, screening ... [more ▼]

Although numerical skills are essential in modern societies, 5- 7 % of the population suffer from mathematical learning disabilities. Due to the hierarchical nature of mathematical knowledge, screening during the earliest stages of learning is essential to intervene efficiently. While different screening tools exist, they rely on verbal instructions and task content, hampering their usefulness in linguistically heterogeneous young school populations. We developed a computerized task that requires subjects to encode both auditory and visual numerical information to successfully respond to the task’s demands. For task instruction, participants were presented a video showing a person correctly solving three easy items of the task, before moving on to a practice session of three different items. If any item was solved incorrectly, the entire practice session was repeated for the participant. We administered the task to a sample of first grade students and collected participant’s performance in standardized addition, subtraction and number comparison (1 & 2-digit) tasks. A multivariate analysis with practice repetition as between-subject factor on the four standardized control measures revealed that participants that repeated the practice session scored significantly lower in three out of four dependent measures. These results suggest that the immediate understanding (i.e. practice items solved correctly on the first try) of our task, requiring deductive reasoning and an abstract, format-independent representation of quantity, is able to differentiate between high and low performers on standardized measures of basic math competence non-verbally at an early stage of learning. Implications and limitations will be discussed. [less ▲]

Automatic discrimination of digits and letters in first graders and adults: an EEG Fast Periodic Visual Stimulation study.

Poster (2018, June)

Both letters and digits are arbitrary visual shapes that are distinguished into categories only after cultural acquisition. The observation that digits are easier to identify than letters has been ... [more ▼]

Both letters and digits are arbitrary visual shapes that are distinguished into categories only after cultural acquisition. The observation that digits are easier to identify than letters has been repeatedly reported in the literature (Shubert, 2017). In the present study, we used a Fast Periodic Visual Stimulation approach with EEG recordings to assess the automatic discrimination of letters and digits from each other in 1st grade children (N=17) and in adults (N=18). Participants viewed 40 sec sequences (3 repetitions per condition) of frequent stimuli (letters or digits) at a fast periodic rate (adults: 10Hz, children: 6Hz), in which rare stimuli (the other category of alphanumeric symbols) were periodically inserted (every five items, e.g., adults: at 2Hz, children: at 1.2Hz). Results showed discrimination responses in both groups in posterior occipito-temporal regions with clear changes in lateralization patterns. In children, stimuli contained only single elements. Responses were right-lateralized for digits among letters, and revealed a trend for left-lateralization for letters among digits. In adults, when stimuli contained only 1 character, both letters and digits gave rise to responses in the RH. However, when strings of characters were presented, then letters were discriminated from digits in the LH. These findings show a developmental pattern where single elements in children seem to be processed like strings of elements in adults. [less ▲]

Surmonter les barrières linguistiques avec « MaGrid » - un outil de formation de pré-mathématiques pour un contexte scolaire multilingue

Scientific Conference (2018, January 11)

Le contexte scolaire luxembourgeois est caractérisé par le multilinguisme et une population scolaire hétérogène, ce qui nécessite la mise en place de pratiques pédagogiques qui prennent en compte ... [more ▼]

Le contexte scolaire luxembourgeois est caractérisé par le multilinguisme et une population scolaire hétérogène, ce qui nécessite la mise en place de pratiques pédagogiques qui prennent en compte l’hétérogénéité des élèves. Dans le domaine des mathématiques, qui semble être non-verbal à première vue, des résultats scientifiques montrent que les enfants dont la langue maternelle est différente de la langue d’instruction, atteignent sur des tests d’aptitudes pré-mathématiques des résultats significativement inférieurs à ceux de leurs camarades natifs. Ceci est d’autant plus inquiétant, sachant que ces aptitudes pré-mathématiques sont prédictives des apprentissages ultérieurs. Par conséquent, nous avons développé l’outil de formation de pré-mathématiques non-verbale « MaGrid ». « MaGrid » permet à chaque enfant de bénéficier pleinement d’une instruction préscolaire en mathématiques, indépendamment de ses compétences langagières. Cet outil se caractérise par sa nature visuelle et il est implémenté sur tablette tactile. Jusqu’à présent, nous avons implémenté et évalué « MaGrid » lors de deux études scientifiques. Les résultats quantitatifs des évaluations empiriques sont prometteurs, comme ils montrent des effets positifs sur les habilités entraînées chez les enfants ayant utilisé cet outil comparé à un groupe contrôle. Dans une première étude, l’outil a été utilisé auprès de cinq classes durant 10 semaines, comprenant deux séances de 20 minutes par semaine. Les résultats lors de petites épreuves spécifiques ont été comparés aux résultats d’élèves de cinq classes n’ayant pas d’entraînement spécifique, et des effets d’intervention ont été observés. Dans une deuxième étude, nous nous sommes focalisés sur un groupe d’enfants de langue minoritaire (le portugais). « MaGrid » a été utilisé lors d’un programme d’intervention de pré-mathématiques s’étendant sur les deux années scolaires de l’école préscolaire. Les analyses préliminaires ont abouti à des résultats positifs. Des effets bénéfiques se sont manifestés sur différentes mesures de pré-mathématiques chez les enfants ayant suivi notre programme par rapport aux enfants du groupe contrôle. [less ▲]

A rapid, objective and implicit measure of visual quantity discrimination

in Neuropsychologia (2018), 111

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 ... [more ▼]

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. [less ▲]

Enjeux soulevés par la technologie dans l’évaluation de compétences

Scientific Conference (2018)

Implicit and explicit number-space associations differentially relate to interference control in young adults with ADHD

in Frontiers in Psychology (2018)