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See detailAssessing the cerebral correlates of non-symbolic number processing with fast periodic visual stimulation
Guillaume, Mathieu UL; Mejias, Sandrine; Rossion, Bruno et al

Poster (2017)

Some authors recently challenged the claim that numerical processes specifically handle non-symbolic magnitudes and they alternately suggested that general visual and/or control executive processes could ... [more ▼]

Some authors recently challenged the claim that numerical processes specifically handle non-symbolic magnitudes and they alternately suggested that general visual and/or control executive processes could explain performance in number comparison tasks. To further investigate this issue, we set up an EEG paradigm in which we recorded neural responses to the passive viewing of different arrays of basic visual forms. The stimuli sequence followed a fast and sinusoidal contrast modulation at the frequency of 10Hz (ten items per second). Visual properties of elements randomly changed from item to item, but their number was manipulated: in a control condition, arrays always contained the same number, and in the experimental conditions, the number periodically changed (each eight iteration, at 1.25Hz). We varied the numerical ratio between the frequent and the rare number throughout the experimental conditions. We recorded significant responses on occipital and parietal electrodes to the oddball frequency and its harmonics during our experimental conditions. Crucially, the strength of the signal was proportionally larger when the numerical ratio was larger. The results suggest that implicit and passive viewing of quick sequence of arrays was sufficient to automatically elicit neural synchronisation to numerical magnitudes without any explicit involvement of higher general cognitive processes. [less ▲]

Detailed reference viewed: 58 (6 UL)
Peer Reviewed
See detailDiscrimination of Numerosities in children studied by means of Fast Periodic Visual Stimulation
Mejias, Sandrine; Rossion, Bruno; Schiltz, Christine UL

Poster (2014)

We are constantly dealing with quantities in our environment. This ability to process numerical magnitude is present in infants (Izard et al., 2009), a variety of animal species (Flombaum et al., 2005 ... [more ▼]

We are constantly dealing with quantities in our environment. This ability to process numerical magnitude is present in infants (Izard et al., 2009), a variety of animal species (Flombaum et al., 2005) and in tribes with small number words lexicon (Pica et al., 2004). It implies that our brain is able to extract the total number of items in a scene, regardless of perceptual interference (non-numerical properties of the stimuli). However, this ability seems to be refined through development (Halberda et al., 2012), due to visual-perception maturation and/or educational environment, e.g. when learning arithmetic. Here, we measured rapidly and objectively 6-to-12-y.o. children’s sensitivity to (non-)symbolic numerical stimuli (dots or Arabic numbers), using fast periodic visual stimulation (FVPS) as implemented in a repetition-suppression paradigm (Rossion & Boremanse, 2011). Children were presented with stimuli appearing at 3.5 items/second (fundamental frequency=3.5 Hz), for 60 seconds. Half of the sequences consisted of different stimuli at every cycle of stimulation (e.g., “10”, “18”, “12”,...), the other half of sequences were composed of same stimuli (“10”) repeated throughout the whole sequence. We observed a large increase of the EEG response at the fundamental frequency (a steady-state visual evoked potential; Regan, 1966) over the lateral parieto-occipital electrodes sites. This response was reduced when the same stimulus was repeated, especially for symbolic stimuli. These results are correlated to children’s age and visual-perception, arithmetic and non-symbolic numerical abilities (L-POST, KRT, Panamath). They indicate that FPVS of (non-)symbolic numerosities is a promising tool to study children’s sensitivity to numerical magnitude. [less ▲]

Detailed reference viewed: 65 (6 UL)
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See detailThe development of number symbol processing: A fast periodic visual stimulation study
Mejias, Sandrine; Rossion, Bruno; Schiltz, Christine UL

Poster (2014)

In our cultures the meaning of number symbols is acquired and reinforced through education. Accordingly, it is critical to understand how children become experts in the use of Arabic numbers (AN). Here ... [more ▼]

In our cultures the meaning of number symbols is acquired and reinforced through education. Accordingly, it is critical to understand how children become experts in the use of Arabic numbers (AN). Here, we used fast periodic visual stimulation (FPVS) combined with a repetition-suppression paradigm (Rossion & Boremanse, 2011) to measure rapidly and objectively the sensitivity to symbolic numerical stimuli of 6-to-12-y.o. children (n=20) and adults (n=11). Participants were presented four sequences: two of AN and two of AN-like sham stimuli. Half of the sequences consisted of different stimuli (“10”, “18”, “12”,...), the other half of same stimuli (“10”) presented repeatedly. Stimuli appeared at 3.5 items/second (fundamental frequency=3.5 Hz), for 60 seconds. We observed a large increase of the EEG response at 3.5 Hz (a steady-state visual-evoked potential; Regan, 1966) over parieto-occipital electrodes. This response was larger during different than same sequences, especially when participants saw real (vs. sham) AN. The amplitude of this specific response to numbers increased with children’s age. Moreover its location changed from posterior occipital electrodes in childhood to more lateral parietal electrodes in adulthood. These results indicate that FPVS of AN is a promising tool to study the sensitivity to numerical magnitude in children and adults. [less ▲]

Detailed reference viewed: 88 (3 UL)
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See detailEstimation abilities of large numerosities in preschool children
Mejias, Sandrine; Schiltz, Christine UL

Poster (2013, October)

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 ... [more ▼]

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. [less ▲]

Detailed reference viewed: 18 (0 UL)
Peer Reviewed
See detailHow the human brain discriminates numerosities: A steady-state visual-evoked potentials study
Mejias, Sandrine; Rossion, Bruno; Schiltz, Christine UL

Poster (2013, May 28)

This study aimed at measuring rapidly and objectively human adults' sensitivity to (non)symbolic numerical stimuli, using the steady-state visual-evoked potentials (1) response in the context of ... [more ▼]

This study aimed at measuring rapidly and objectively human adults' sensitivity to (non)symbolic numerical stimuli, using the steady-state visual-evoked potentials (1) response in the context of repetition suppression (2). It aimed to demonstrate the feasibility of the method and evaluate its potential to tap into the basic numerical representation systems that can be assumed to underlie symbolic and non-symbolic magnitude comparisons. Following a short duration experiment, we observed a large reduction of signal specifically at the 3.5 Hz response, over the occipito-temporo-parietal cortex. This reduction was greater for symbolic than non-symbolic control stimuli. This first observation of repetition suppression to fast periodic stimulation of symbolic and non-symbolic numerosities in the human brain offers a promising tool to study the sensitivity to numerosities in the human brain in adults, but also especially in children. [less ▲]

Detailed reference viewed: 28 (1 UL)
Peer Reviewed
See detailEstimation abilities of large numerosities in preschool children: Do they depend on school grade and socio-economic background?
Mejias, Sandrine; Schiltz, Christine UL

Poster (2013, March 01)

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 ... [more ▼]

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. [less ▲]

Detailed reference viewed: 35 (0 UL)
Peer Reviewed
See detailHow the human brain discriminates numerosities: A steady-state visual-evoked potentials study
Mejias, Sandrine; Rossion, Bruno; Schiltz, Christine UL

Poster (2013)

This study aimed at measuring rapidly and objectively human adults' sensitivity to (non)symbolic numerical stimuli, using the steady-state visual-evoked potentials (1) response in the context of ... [more ▼]

This study aimed at measuring rapidly and objectively human adults' sensitivity to (non)symbolic numerical stimuli, using the steady-state visual-evoked potentials (1) response in the context of repetition suppression (2). It aimed to demonstrate the feasibility of the method and evaluate its potential to tap into the basic numerical representation systems that can be assumed to underlie symbolic and non-symbolic magnitude comparisons. Following a short duration experiment, we observed a large reduction of signal specifically at the 3.5 Hz response, over the occipito-temporo-parietal cortex. This reduction was greater for symbolic than non-symbolic control stimuli. This first observation of repetition suppression to fast periodic stimulation of symbolic and non-symbolic numerosities in the human brain offers a promising tool to study the sensitivity to numerosities in the human brain in adults, but also especially in children. [less ▲]

Detailed reference viewed: 36 (7 UL)
Full Text
Peer Reviewed
See detailEstimation abilities of large numerosities in Kindergartners.
Mejias, Sandrine; Schiltz, Christine UL

in Frontiers in psychology (2013), 4

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 ... [more ▼]

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. [less ▲]

Detailed reference viewed: 57 (0 UL)
Full Text
See detailEstimation abilities of large numerosities in preschool children
Mejias, Sandrine; Schiltz, Christine UL

Presentation (2012, February 17)

Detailed reference viewed: 13 (1 UL)