Attentional shifts induced by uninformative number symbols modulate neural activity in human occipital cortex

in Neuropsychologia (2012), 50

Number processing interacts with space encoding in a wide variety of experimental paradigms. Most intriguingly, the passive viewing of uninformative number symbols can shift visuo-spatial attention to ... [more ▼]

Number processing interacts with space encoding in a wide variety of experimental paradigms. Most intriguingly, the passive viewing of uninformative number symbols can shift visuo-spatial attention to different target locations according to the number magnitude, i.e., small/large numbers facilitate processing of left/right targets, respectively. The brain architecture dedicated to these attention shifts associated with numbers currently remains unknown. Evoked potential recordings indicate that both early and late stages are involved in this spatio-numerical interaction, but the neuro-functional anatomy needs to be specified. Here we use, for the first time, functional magnetic resonance imaging (fMRI) to investigate attentional orienting following uninformative Arabic digits. We show that BOLD response in occipital visual regions was modulated by the congruency between digit magnitude (small/large) and target side (left/right). Additionally, we report higher BOLD responses following large (8, 9) compared to small (1, 2) digits in two bilateral parietal regions, yielding a significant effect of digit magnitude. We propose and discuss the view that encoding of semantic representations related to number symbols in parietal cortex led to shifts in visuo-spatial attention and enhanced visual processing in the occipital cortex according to number-space congruency rules. [less ▲]

The interaction between number and space processing and math achievement in adults

Poster (2012, September 07)

Behavioral studies show a relation between numbers and space (for a review see De Hevia et al., 2008). One instance of this link is the SNARC (Spatial Numerical Association of Response Codes) effect ... [more ▼]

Behavioral studies show a relation between numbers and space (for a review see De Hevia et al., 2008). One instance of this link is the SNARC (Spatial Numerical Association of Response Codes) effect, consisting in faster reaction times responding to small/large digits with the left/right hand respectively (Dehaene et al. 1993). The SNARC effect has often been replicated, but it is also characterized by high inter-subject variability (Wood et al. 2006 a,b). Although differences in mathematical skills are an obvious candidate source for SNARC variability, this variable has not yet been explored systematically. For the present study, three groups of participants were recruited amongst University students; one group included only participants reporting specific problems related to numerical processing, and two control groups differing in the math requirements of their field of study (i.e. science students vs. literature students). Results confirmed that the three groups differed substantially in basic arithmetic scores [F(2,92)=19.97, p<0.001] as well as in the strength of their SNARC effect [F(2,92)=7.12, p=0.001]. The science group had the highest arithmetic score and the smallest SNARC effect and the problem report group had the lowest arithmetic score and the strongest SNARC effect, with the literature group lying in between. Rearranging the groups based on arithmetic performance yielded the same results. Correlation analyses confirmed this finding by revealing a strong relation between arithmetic scores and SNARC effect independently of group constitution [r=-0.28, p<0.01]. Different hypotheses in the context of the relevant literature are discussed. [less ▲]

Orientation tuning for faces in the Fusiform Face Area and Primary Visual Cortex

Scientific Conference (2012, September)

The effect of language and mode on two-digit magnitude judgments in German-French bilingual adults

Presentation (2012, July 17)

The study examined the effect of language and presentation mode on numerical processing skills in German-French bilinguals. This bilingual combination is particularly interesting because the order of two ... [more ▼]

The study examined the effect of language and presentation mode on numerical processing skills in German-French bilinguals. This bilingual combination is particularly interesting because the order of two digit number words is inversed in both languages: decade-unit in French but unit-decade in German. Further, previous studies used written number word presentations as verbal notation to activate language, which are, however, rarely used in everyday life. The present study therefore tackled the question whether two-digit magnitude judgments are affected by the presentation mode (visual Arabic vs. auditory words) and the language (German vs. French)? Data stem from proficient German-French bilinguals (mean age: 25,3 years. The within-subject design involved two-digit number pair comparisons presented visually and auditory in German and in French. In line with previous studies, participants responded faster and more accurately on compatible than on incompatible trials in the visual Arabic presentation mode in both languages (compatibility effect): In compatible number pairs, the decades and units concord to the same magnitude decision (e.g. 23_57; decade: 2<5 and unit:3<7) whereas decade and units discord (47_82; decade: 4<8 but 7>2) for incompatible number pairs. In the auditory mode, the results showed a tendency for a regular compatibility effect in German and an inverse compatibility effect in French with participants responding faster on incompatible trials suggesting that bilinguals process numerical tasks in the language of presentation similar to monolinguals using the same language. Conclusively, the results imply differential numerical processing according to the presentation mode (visual Arabic vs. auditory words) and the language (German vs. French). [less ▲]

Que fait un professeur d`université qui travaille dans le domaine des neurosciences cognitives?

Conference given outside the academic context (2012)

How does language affect numerical processing? The role of the teaching language on two-digit magnitude judgments in German-French bilingual 7- to-11 graders

Poster (2012, May)

Estimation abilities of large numerosities in preschool children

Presentation (2012, February 17)

The SNARC effect – Does it depend on the level of mathematical training?

Scientific Conference (2012, February 10)

The effect of number syntax on two-digit magnitude judgments in German-French bilinguals.

Poster (2012, February)

The study examined the effect of language and presentation mode on numerical processing skills in German-French bilinguals. This bilingual combination is particularly interesting because the order of two ... [more ▼]

The study examined the effect of language and presentation mode on numerical processing skills in German-French bilinguals. This bilingual combination is particularly interesting because the order of two digit number words is inversed in both languages: decade-unit in French but unit-decade in German. Further, previous studies used written number word presentations as verbal notation to activate language, which are, however, rarely used in everyday life. The present study therefore tackled the question whether two-digit magnitude judgments are affected by the presentation mode (visual Arabic vs. auditory words) and the language (German vs. French)? Data stem from adult participants (mean age: 25,3 years) who were proficient German-French bilinguals. The within-subject design involved two-digit number pair comparisons presented visually and auditory in German and in French. In line with previous studies, participants responded faster and more accurately on compatible than on incompatible trials in the visual Arabic presentation mode in both languages (compatibility effect): In compatible number pairs, the decades and units concord to the same magnitude decision (e.g. 23_57; decade: 2<5 and unit:3<7) whereas decade and units discord (47_82; decade: 4<8 but 7>2) for incompatible number pairs. In the auditory mode, the results showed a tendency for a regular compatibility effect in German and an inverse compatibility effect in French with participants responding faster on incompatible trials suggesting that bilinguals process numerical tasks in the language of presentation similar to monolinguals using the same language. Conclusively, the results imply differential numerical processing according to the presentation mode (visual Arabic vs. auditory words) and the language (German vs. French). [less ▲]

A developmental investigation of the SNARC effect using a colour discrimination task.

Poster (2012)

How do number-space interactions develop from childhood to adulthood? The SNARC effect (Spatial Numerical Association of Response Codes) reflects the finding that participants respond faster to small ... [more ▼]

How do number-space interactions develop from childhood to adulthood? The SNARC effect (Spatial Numerical Association of Response Codes) reflects the finding that participants respond faster to small numbers with their left hand and to large numbers with their right hand during a number classification task. Typically assessed through magnitude-independent parity judgment tasks, the SNARC effect is thought to show the automaticity of the number-space link. Using a parity task on children Berch et al. (1999) found a SNARC effect no earlier than from 9.2 years onwards. However, we hypothesise that parity judgments might be inappropriate to assess younger children. Therefore a more age-appropriate colour judgment task (implicit) and a magnitude judgement task (explicit) were designed and tested on 363 children from kindergarten to Grade 6 (5.8-12 years). The experimental tasks were complemented by a brief assessment of arithmetic skills. The results revealed overall significant SNARC effects [colour task t(355)=2.6, p<0.01; magnitude task t(340)=4.7, p<0.001], which interacted with grade [colour task F(6,355)=2.18; p<0.05; magnitude task F(6,340)=2.09; p=0.05]. Most interestingly, even the kindergartners already display both effects [colour task t(28)=1.96; p<0.05; magnitude task t(24)=1.7; p=0.05]. These results show explicit and implicit access to numerical magnitude in children as young as 5.8 years. [less ▲]