References of "Guillaume, Mathieu 50001907"
     in
Bookmark and Share    
Full Text
See detailAre parity and magnitude status of Arabic digits processed automatically? An EEG study using the fast periodic visual stimulation
Poncin, Alexandre UL; Van Rinsveld, Amandine; Guillaume, Mathieu UL et al

Presentation (2017, February 22)

Many studies have shown that humans can easily extract numerical characteristics of single digits such as numerical magnitude and parity status. We investigated whether spontaneous processing of magnitude ... [more ▼]

Many studies have shown that humans can easily extract numerical characteristics of single digits such as numerical magnitude and parity status. We investigated whether spontaneous processing of magnitude or parity status can be observed when participants are passively presented with sequences of briefly displayed Arabic digits. We assessed the parity processing by presenting seven odd digit numbers followed by one even digit (and reverse) with a sinusoidal contrast modulation at a frequency of 10HZ in one-minute sequences. The same paradigm and frequencies were used to investigate magnitude processing (i.e. seven digits smaller than five followed by one digit larger than five; and reverse) and control condition (i.e. sequence of 1-4-6-9 followed by 2-3-7 or 8). We observed a strong EEG activation on right parietal electrodes and a weaker activation on left parietal electrodes in all conditions. Left and right activations were stronger in the parity than in the other conditions, reflecting an automatic retrieval of parity information conveyed by the Arabic digits. The weaker activation during the magnitude task could reflect a more complicated access of the information corresponding to magnitude status. Right activations during the control task could be due to the fact that subjects can quickly learn to categorize numbers arbitrarily. These neuronal activation patterns are consistent with the neuro-imaging literature describing the localization of basic numerical processing. Our findings indicate that magnitude and parity status are extracted automatically from Arabic digits, even when numerical stimuli are presented without instructions at a high presentation rate. [less ▲]

Detailed reference viewed: 12 (1 UL)
Peer Reviewed
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: 26 (3 UL)
Full Text
Peer Reviewed
See detailMental arithmetic in the bilingual brain: Language matters.
Van Rinsveld, Amandine; Dricot, Laurence; Guillaume, Mathieu UL et al

in Neuropsychologia (2017), 101

How do bilinguals solve arithmetic problems in each of their languages? We investigated this question by exploring the neural substrates of mental arithmetic in bilinguals. Critically, our population was ... [more ▼]

How do bilinguals solve arithmetic problems in each of their languages? We investigated this question by exploring the neural substrates of mental arithmetic in bilinguals. Critically, our population was composed of a homogeneous group of adults who were fluent in both of their instruction languages (i.e., German as first instruction language and French as second instruction language). Twenty bilinguals were scanned with fMRI (3T) while performing mental arithmetic. Both simple and complex problems were presented to disentangle memory retrieval occuring in very simple problems from arithmetic computation occuring in more complex problems. In simple additions, the left temporal regions were more activated in German than in French, whereas no brain regions showed additional activity in the reverse constrast. Complex additions revealed the reverse pattern, since the activations of regions for French surpassed the same computations in German and the extra regions were located predominantly in occipital regions. Our results thus highlight that highly proficient bilinguals rely on differential activation patterns to solve simple and complex additions in each of their languages, suggesting different solving procedures. The present study confirms the critical role of language in arithmetic problem solving and provides novel insights into how highly proficient bilinguals solve arithmetic problems. [less ▲]

Detailed reference viewed: 70 (9 UL)
Peer Reviewed
See detailCardinal and ordinal processing in spatial neglect
Sosson, Charlotte UL; di Luca, Samuel UL; Guillaume, Mathieu UL et al

Poster (2016, January)

Patients with spatial neglect do not only have difficulties in orienting attention in physical space but also in representational space, especially with respect to the mental representation of numbers ... [more ▼]

Patients with spatial neglect do not only have difficulties in orienting attention in physical space but also in representational space, especially with respect to the mental representation of numbers. Indeed, in a study by Zorzi et al. (2012) neglect patients were particularly slow when asked to compare the number 4 to the standard number 5, suggesting difficulties to process numbers on the left side of an internal standard. This difficulty was observed in a magnitude judgement, but not in a parity task, implying a dissociation between explicit and implicit processing of numerical magnitude. The present study aimed at replicating these findings and extending them to non-numerical sequences in order to complement the data obtained on bisection tasks (Zamarian, et al., 2007). Sixteen right-sided brain damaged patients with neglect (N+ =6; 4 females; all right handers; mean age: 55 +/- 8,7) and without neglect (N- =10; 2 females; all right hander; mean age: 48 +/- 6.2) participated in the study. They were administered the following tasks: a magnitude and a parity judgement task; an ordinal judgement task on numbers and on letters and a consonant/vowel classification task. For each task and each patient, a linear regression was computed in which the difference between the response times for the left effector (index finger) and the right effector (middle finger) was predicted by number magnitude. A negative slope will indicate the presence of a SNARC-like effect. We compared the negative slopes of the two patient groups using a Chi-square. Considering the proportion of SNARC-like effects, it appeared that, on one hand, N+ patients showed fewer SNARC-like effects than N- patients during magnitude judgements on numbers. Thus confirming the findings by Zorzi et al. (2012). On the other hand, N+ patients behaved similarly to N- patients for the parity judgements on numbers and for the order judgements both on numbers and letters. This last result suggest a dissociation between the spatial representation of magnitude and of order in N+ patients. These results point towards a specific impairment in explicit access to number magnitude in spatial hemineglect. [less ▲]

Detailed reference viewed: 64 (14 UL)
Peer Reviewed
See detailDoes body motion influence arithmetic problem solving
Sosson, Charlotte UL; Guillaume, Mathieu UL; Schuller, Anne-Marie UL et al

Poster (2015, September)

Recent evidence indicates that body movements can influence number processing (Hartmann, et al., 2012) and arithmetic problem solving (Lugli, et al., 2013). Thus it was for instance observed that moving ... [more ▼]

Recent evidence indicates that body movements can influence number processing (Hartmann, et al., 2012) and arithmetic problem solving (Lugli, et al., 2013). Thus it was for instance observed that moving the arm rightward and upward led to better performance during additions and leftward and downward during subtractions (Wiemers, et al., 2014). These results could be explained by the fact that left/right body motion can be (in)compatible with the attentional motion towards the left/right on the mental number line known to underlie subtractions/additions (i.e. operational momentum effect) (McCrink, et al., 2007; Lindemann, et al., 2011). The compatible situations (i.e. leftwards motion - subtraction and rightwards motion - addition) thus are expected to facilitate arithmetic performance compared to incompatible ones. The present study was designed to test this hypothesis during arithmetic problem solving using: (1) physical passive rotary whole-body motion and (2) virtual environment mimicking a similar passive body motion. Findings of the present study confirm the classical effects known to play a role in arithmetic problem solving. They also revealed that passive rotary whole-body motion - implemented physically or by virtual reality - had no particular effect on the solving of calculations. This is in contrast with previous studies that showed an influence of active head/arm or passive translational movements on numerical task performance. [less ▲]

Detailed reference viewed: 26 (6 UL)
Peer Reviewed
See detailFunctional connectivity and structural analyses in the bilingual brain: implications for arithmetic.
Van Rinsveld, Amandine UL; Dricot, Laurence; Guillaume, Mathieu UL et al

Poster (2015, June)

Do bilinguals use the same brain networks than monolinguals when they solve arithmetic problems? We investigated this question by using resting-state functional connectivity and cortical thickness ... [more ▼]

Do bilinguals use the same brain networks than monolinguals when they solve arithmetic problems? We investigated this question by using resting-state functional connectivity and cortical thickness measurements. Recent studies highlighted differences of functional connectivity (e.g. Grady et al., 2015) and of brain structure (e.g. Klein et al., 2014) between bilinguals and monolinguals. However, no study so far has linked these differences to arithmetic problem solving, a cognitive skill that may at least partially rely on language processing. Our study population was composed of carefully selected German-French bilinguals (N = 20) who acquired each language at the same age, leading to high proficiency levels in both languages. These bilinguals all attended university in their second language at the time of the experiment, namely French. Therefore we selected a control group of French-speaking monolinguals (N = 12). Structural and functional images of brain activity were collected using a 3T MRI scanner. Functional scans of resting-state were acquired during a 6-minute session, with eyes closed. A 3D T1-weighted data set encompassing the whole brain was acquired to provide detailed anatomy (1 mm3), which was used both for the co-registration of functional data and for morphometric analyses. Prior to the scanning session, all participants took a behavioral test measuring their arithmetic skill. For the resting-state part of the study, we generated spheres based on ROIs reported in the literature as magnitude manipulation- and language-related areas during arithmetic problem solving (Klein et al. 2013), and addition-related areas reported in a recent meta-analysis (Arsalidou & Tayor, 2011). We used these spheres as seed regions for the analyses. We correlated resting activations between these regions and compared these correlations in bilinguals versus monolinguals. Results showed significantly higher correlations between the three seed regions in monolinguals than in bilinguals (all ts > 2.306; ps < .05), suggesting that regions used to solve arithmetic problems form a different network in bilinguals than in monolinguals. To control for general differences between both populations, we also created two spheres in areas not specifically related to neither arithmetic nor language regions. There were no significant differences between groups in terms of correlations of these regions with resting-state activations. These results suggest that the differences observed in arithmetic problem solving regions could not account for by general differences between groups. In the second part of the study, we aimed at verifying whether the differences in functional connectivity we observed between bilinguals and monolinguals coincide with structural brain differences. We measured and compared cortical thickness in both groups. Then we compared the correlations between cortical thickness and arithmetic skill in both groups (considering differences with corrected p < .001). Cortical thickness of areas commonly associated to language or number processing correlated differently with arithmetic skill as a function of the group: Higher cortical thickness of left pars triangularis, bilateral superior parietal gyri and precuneus positively correlated with arithmetic skill in monolinguals but negatively correlated with arithmetic skill in bilinguals. These results highlight that there are different relations between brain structure and arithmetic skills in bilinguals and monolinguals. In conclusion the current study provides new evidence for differences between bilinguals’ and monolinguals’ brain networks engaged in arithmetic problem solving, even without any arithmetic task during the data acquisition. These findings based on functional connectivity and brain structure analyses also reveal the general involvement of language in arithmetic problem solving in bilingual as well as non-bilingual individuals. [less ▲]

Detailed reference viewed: 39 (8 UL)
Peer Reviewed
See detailNeural correlates of arithmetic problem solving in bilinguals: an fMRI study.
Van Rinsveld, Amandine UL; Dricot, Laurence; Guillaume, Mathieu UL et al

Poster (2015, May)

Detailed reference viewed: 47 (1 UL)
Peer Reviewed
See detailDoes body motion influence arithmetic
Sosson, Charlotte UL; Guillaume, Mathieu UL; Schuller, Anne-Marie UL et al

Poster (2015, March)

« Embodiment theory » proposes that bodily actions impact the quality of mental representations. Two recent studies (Loetscher, et al., 2008; Hartmann, et al., 2011) have shown that leftward movements of ... [more ▼]

« Embodiment theory » proposes that bodily actions impact the quality of mental representations. Two recent studies (Loetscher, et al., 2008; Hartmann, et al., 2011) have shown that leftward movements of the head or the body enhanced small number generation while rightward movements increased the generation of larger numbers. The present study aimed to investigate the influence of passive whole-body movement on arithmetic-problem solving. Our design was elaborated in the context of operational momentum effect (Pinhas, & Fischer, 2008; McCrink, et al., 2007). In the domain of arithmetic this effect refers to the fact that outcomes of additions are systematically estimated to be larger than the outcomes of subtractions and vice versa for subtraction (Knops, et al., 2009; Lindemann, et al., 2011). Interestingly this bias is present for non-carry but not for carry problems. To account for the operational momentum effect it has been proposed that subtractions involve an attentional motion towards the left of the mental number line and additions towards the right inducing the above-mentioned under- and over-estimation. In line with these findings we reasoned that passive body motion might orient attention towards the side of the body movement and consequently enhance the attentional shifts supposed to underlie the operational momentum effects that occur during numerical tasks. In the present paradigm participants were sitting blindfolded on a swivel chair. While they were rotated alternatively 180° towards the left and the right with a pace of 49°/sec., they were asked to orally solve different kinds of calculations presented via headphones. Calculations consisted in additions and subtractions (first operand: from 1 to 98; second operand: from 1 to 13 and results: from 3 to 89) that were composed of carry and non-carry problems and had different levels of difficulty (easy: results from 1 to 9; medium: results from 11 to 19; difficult: from 21 to 89). Contrary to our predictions, results indicate that the direction of passive body motion (i.e. leftwards vs. rightwards) did not influence arithmetic performance. Indeed the ANOVA for repeated measures with the factor Motion (left, right), Problem type (carry, non-carry) and Operation type (addition, subtraction) revealed no main effect of motion (F(1,33)= 0,856, p=0.361). In contrast we observed a main effect of Problem type (F(1,33)=29.065, p<0.001), a main effect of Operation type (F(1,33)= 20,721, p<0.001) and a significant interaction of Problem type x Operation type (F(1,30)=5.605,p=0.024). As would be expected from the results observed with classical stationary experiment settings, participants were more accurate while solving additions than subtractions and made less errors with non-carry problems. Moreover the carry effect was larger for subtractions than additions. Analyses of the reaction times led to the same conclusions. These results indicate that orally solving arithmetic problems is not influenced by the direction (leftwards vs. rightwards) of passive rotary body-motion. This finding contrasts with previous observations that active head movements and/or passive translational movements impacts numerical task performance. Future studies which systematically contrast the effects of the different movement types on numerical tasks should help to clarify this discrepancy. [less ▲]

Detailed reference viewed: 18 (2 UL)
Peer Reviewed
See detailArithmetic in the bilingual brain: an fMRI study
Van Rinsveld, Amandine UL; Dricot, Laurence; Guillaume, Mathieu UL et al

Scientific Conference (2015, March)

Using fMRI we observed that solving addition and multiplication problems induced activation in several fronto-parietal regions in both German-French bilingual and French monolingual adults. However ... [more ▼]

Using fMRI we observed that solving addition and multiplication problems induced activation in several fronto-parietal regions in both German-French bilingual and French monolingual adults. However, during complex addition frontal regions showed systematically higher activation levels in bilinguals than monolinguals, both when bilinguals computed in German (math-acquisition language) and in French. [less ▲]

Detailed reference viewed: 44 (7 UL)
Full Text
Peer Reviewed
See detailAssessing the Approximate Number System: no relation between numerical comparison and estimation tasks
Guillaume, Mathieu UL; Gevers, Wim; Content, Alain

in Psychological Research (2015)

Whether our general numerical skills and the mathematical knowledge that we acquire at school are entwined is a debated issue, which many researchers are still striving to investigate. The findings ... [more ▼]

Whether our general numerical skills and the mathematical knowledge that we acquire at school are entwined is a debated issue, which many researchers are still striving to investigate. The findings reported in the literature are actually inconsistent; some studies emphasised the existence of a relationship between the acuity of the Approximate Number System (ANS) and arithmetic competence, while some others did not observe any significant correlation. One potential explanation of the discrepancy might stem from the evaluation of the ANS itself. In the present study, we correlated two measures used to index ANS acuity with arithmetic performance. These measures were the Weber fraction (w), computed from a numerical comparison task and the Coefficient of Variation (CV), computed from a numerical estimation task. Arithmetic performance correlated with estimation CV but not with comparison w. We further investigated the meaning of this result by taking the relationship between w and CV into account. We expected a tight relation as both these measures are believed to assess ANS acuity. Crucially however, w and CV did not correlate with each other. Moreover, the value of w was modulated by the congruity of the relation between numerical magnitude and non-numerical visual cues, potentially accounting for the lack of correlation between the measures. Our findings thus challenge the overuse of w to assess ANS acuity and more generally put into question the relevance of correlating this measure with arithmetic without any deeper understanding of what they are really indexing. [less ▲]

Detailed reference viewed: 51 (5 UL)
Peer Reviewed
See detailArithmetic in the Bilingual Brain: an fMRI study
Van Rinsveld, Amandine UL; Dricot, Laurence; Guillaume, Mathieu UL et al

Scientific Conference (2014, May)

How do bilinguals solve arithmetic problems in their different languages? We investigated this question with functional magnetic resonance imaging (fMRI) by exploring the neural substrates of arithmetic ... [more ▼]

How do bilinguals solve arithmetic problems in their different languages? We investigated this question with functional magnetic resonance imaging (fMRI) by exploring the neural substrates of arithmetic processing in bilinguals in comparison to monolinguals. Bilingual participants were highly proficient both in German and French as they attended primary school in German and secondary school and higher education in French. This bilingual combination is particularly interesting because the order of two-digit number words is inversed in these languages: decade-unit in French but unit-decade in German. 21 German-French bilinguals and 12 French-speaking monolinguals were scanned while performing different types of arithmetic problems: additions of different complexity levels (from simple to complex additions) and multiplication facts. We presented different types of operations in order to disentangle arithmetic computation from pure memory retrieval that occurs in very simple additions or multiplications. Arithmetic problems were presented via headsets in a verification paradigm and bilinguals performed the tasks in both languages. Results showed that all arithmetic tasks elicited a broad fronto-parietal network in both groups and for both of bilinguals’ language sessions. However, we observed that complex additions involved more left frontal activity (i.e. inferior frontal gyrus, anterior cingulate gyrus) in bilinguals than in monolinguals. It is important to notice that these frontal activation differences occurred both for the arithmetic acquisition language (i.e. German) and the second language (i.e. French). These BOLD differences between bilingual and monolingual participants were observed despite the fact that both groups solved the arithmetic problems with equivalent accuracy rates. Moreover, localization of the regions activated by complex additions in bilinguals differed from the typical activation pattern reported for mental arithmetic in recent meta-analyses (Arsalidou & Taylor, 2011). Taken together, our results indicate that highly proficient bilinguals rely on differential activation patterns than monolinguals to solve complex additions. The differences in left frontal activations might reflect different degrees of language-related automaticity when computing complex arithmetic problems. Executive functions that are necessary to control language context and access for bilinguals’ respective languages might also play a role. Further insights about the role of language in arithmetic solving process in bilingual and non-bilingual individuals will be discussed. [less ▲]

Detailed reference viewed: 327 (12 UL)
Peer Reviewed
See detailThe influence of body motion on random number generation
Sosson, Charlotte UL; Guillaume, Mathieu UL; Van Rinsveld, Amandine UL et al

Poster (2014)

Knowledge and thinking are constrained by sensory-motor processes. This increasingly influential view has been termed the “embodiment theory” and proposes that bodily actions directly impact the quality ... [more ▼]

Knowledge and thinking are constrained by sensory-motor processes. This increasingly influential view has been termed the “embodiment theory” and proposes that bodily actions directly impact the quality of mental representations. The present study specifically aimed to investigate the influence of passive whole-body movement on numerical cognition. Two recent studies (Loetscher, et al., 2008; Hartmann, et al. 2011) indeed indicate that head or body movements can induce a shift of the attention on the mental number line. More precisely, leftward movements seemed to enhance small number generation while rightward movements led to larger number generation. The current study investigated this effect by using a non-motorized rotating chair. Concretely, while seated, participants were cyclically rotated 40 times for a movement amplitude of 90° from left to right and vice versa at an average frequency of 0.3 Hz. During each 90° movement segment they had to randomly produce numbers ranging between 1 and 30, but for methodological reasons the six extreme numbers were excluded from the analysis. The results indicate that the average number produced during leftward movement was smaller than the average number produced during rightward movement. These findings confirm the impact of passive whole-body movement on the production of numerical stimuli, indicating that rotation-movements of the body can displace attention on the mental number line. [less ▲]

Detailed reference viewed: 78 (19 UL)
Peer Reviewed
See detailNeural correlates of the acquisition of a motor expertise with extended practice: A fMRI study
Borragan Pedraz, Guillermo; Guillaume, Mathieu UL; Atas, Anne et al

Poster (2013)

Detailed reference viewed: 68 (1 UL)
Full Text
Peer Reviewed
See detailDifferences in the acuity of the Approximate Number System in adults: The effect of mathematical ability
Guillaume, Mathieu UL; Nys, Julie; Mussolin, Christophe et al

in Acta psychologica (2013), 144(3), 506-512

It is largely admitted that processing numerosity relies on an innate Approximate Number System (ANS), and recent research consistently observed a relationship between ANS acuity and math ability in ... [more ▼]

It is largely admitted that processing numerosity relies on an innate Approximate Number System (ANS), and recent research consistently observed a relationship between ANS acuity and math ability in childhood. However, studies assessing this relationship in adults led to contradictory results. In this study, adults with different levels of mathematical expertise performed two tasks on the same pairs of dot collections, based either on numerosity comparison or on cumulative area comparison. Number of dots and cumulative area were congruent in half of the stimuli, and incongruent in the other half. The results showed that adults with higher math ability obtained lower Weber fractions in the numerical condition than participants with lower math ability. Further, adults with lower math ability were more affected by the interference of the continuous dimension in the numerical comparison task, whereas conversely higher-expertise adults showed stronger interference of the numerical dimension in the continuous comparison task. Finally, ANS acuity correlated with arithmetic performance. Taken together, the data suggest that individual differences in ANS acuity subsist in adulthood, and that they are related to math ability. [less ▲]

Detailed reference viewed: 39 (3 UL)
Peer Reviewed
See detailProcedural and magnitude-based strategies in solving complex additions: Insights from fMRI
Guillaume, Mathieu UL; Peigneux, Philippe; Borragan Pedraz, Guillermo et al

Poster (2013)

Detailed reference viewed: 17 (1 UL)
Peer Reviewed
See detailProcedural and magnitude-based strategies in solving complex additions
Guillaume, Mathieu UL; Content, Alain

Scientific Conference (2013)

Detailed reference viewed: 5 (0 UL)
Peer Reviewed
See detailWeber Fraction as an index of the acuity of the ANS and its relationship to arithmetic performance by adults
Guillaume, Mathieu UL; Mussolin, Christophe; Nys, Julie et al

Scientific Conference (2012)

Detailed reference viewed: 37 (0 UL)
Peer Reviewed
See detailThe relation between the acuity of the ANS and general arithmetic performance
Guillaume, Mathieu UL; Mussolin, Christophe; Nys, Julie et al

Scientific Conference (2012)

Detailed reference viewed: 24 (0 UL)