References of "Schiltz, Christine 50003015"
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See detailEstimation abilities of large numerosities in preschool children
Mejias, Sandrine; Schiltz, Christine UL

Presentation (2012, February 17)

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See detailThe SNARC effect – Does it depend on the level of mathematical training?
Hoffmann, Danielle UL; Mussolin, Christophe; Schiltz, Christine UL

Scientific Conference (2012, February 10)

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See detailShifts of spatial attention cued by irrelevant numbers: Electrophysiological evidence from a target discrimination task
Schuller, Anne-Marie UL; Hoffmann, Danielle UL; Schiltz, Christine UL

Poster (2012, February 10)

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects ... [more ▼]

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects as event-related potentials (ERPs) at centro-parietal sites. Since both studies used target detection tasks, it remains currently unknown whether similar results would be obtained with a discrimination task. We used ERPs to test whether digit cues also induce attention shifts when participants perform a feature-discrimination task on targets. ERPs were recorded whereas subjects discriminated the colour of lateral targets that were preceded by a central non-predictive digit. Analysis of cue-locked controlateral vs. ipsilateral ERP activity showed the emergence of early preparatory attention-directing components in parietal and frontal regions. Moreover, target-locked P1 components at occipito-parietal sites were significantly modulated by digit magnitude-target side congruency. These results demonstrate that irrelevant digit cues also bias sensory processing when embedded in a feature-discrimination task. [less ▲]

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See detailThe effect of number syntax on two-digit magnitude judgments in German-French bilinguals.
Van Rinsveld, Amandine UL; Ugen, Sonja UL; Schiltz, Christine UL et al

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 ▲]

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See detailLocal discriminability determines the strength of holistic processing for faces in the fusiform face area.
Goffaux, Valerie; Schiltz, Christine UL; Mur, Marieke et al

in Frontiers in psychology (2012), 3

Recent evidence suggests that the Fusiform Face Area (FFA) is not exclusively dedicated to the interactive processing of face features, but also contains neurons sensitive to local features. This suggests ... [more ▼]

Recent evidence suggests that the Fusiform Face Area (FFA) is not exclusively dedicated to the interactive processing of face features, but also contains neurons sensitive to local features. This suggests the existence of both interactive and local processing modes, consistent with recent behavioral findings that the strength of interactive feature processing (IFP) engages most strongly when similar features need to be disambiguated. Here we address whether the engagement of the FFA into interactive versus featural representational modes is governed by local feature discriminability. We scanned human participants while they matched target features within face pairs, independently of the context of distracter features. IFP was operationalized as the failure to match the target without being distracted by distracter features. Picture-plane inversion was used to disrupt IFP while preserving input properties. We found that FFA activation was comparably strong, irrespective of whether similar target features were embedded in dissimilar contexts(i.e., inducing robust IFP) or dissimilar target features were embedded in the same context (i.e., engaging local processing). Second, inversion decreased FFA activation to faces most robustly when similar target features were embedded in dissimilar contexts, indicating that FFA engages into IFP mainly when features cannot be disambiguated at a local level. Third, by means of Spearman rank correlation tests, we show that the local processing of feature differences in the FFA is supported to a large extent by the Occipital Face Area, the Lateral Occipital Complex, and early visual cortex, suggesting that these regions encode the local aspects of face information. The present findings confirm the co-existence of holistic and featural representations in the FFA. Furthermore, they establish FFA as the main contributor to the featural/holistic representational mode switches determined by local discriminability. [less ▲]

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See detailA developmental investigation of the SNARC effect using a colour discrimination task.
Hoffmann, Danielle UL; Hornung, Caroline UL; Mussolin, Christophe et al

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 ▲]

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See detailWhen numbers act as attentional cues: behavioral, EEG and fMRI investigations
Schiltz, Christine UL

Presentation (2011, December 16)

Detailed reference viewed: 108 (7 UL)
See detailLe cerveu à l`école
Schiltz, Christine UL

Conference given outside the academic context (2011)

Detailed reference viewed: 36 (2 UL)
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See detailThe horizontal tuning of face perception relies on the processing of intermediate and high spatial frequencies
Goffaux, Valerie; van Zon, Jaap; Schiltz, Christine UL

in Journal of Vision (2011), 11(10), 1-9

It was recently shown that expert face perception relies on the extraction of horizontally oriented visual cues. Pictureplane inversion was found to eliminate horizontal, suggesting that this tuning ... [more ▼]

It was recently shown that expert face perception relies on the extraction of horizontally oriented visual cues. Pictureplane inversion was found to eliminate horizontal, suggesting that this tuning contributes to the specificity of face processing. The present experiments sought to determine the spatial frequency (SF) scales supporting the horizontal tuning of face perception. Participants were instructed to match upright and inverted faces that were filtered both in the frequency and orientation domains. Faces in a pair contained horizontal or vertical ranges of information in low, middle, or high SF (LSF, MSF, or HSF). Our findings confirm that upright (but not inverted) face perception is tuned to horizontal orientation. Horizontal tuning was the most robust in the MSF range, next in the HSF range, and absent in the LSF range. Moreover, face inversion selectively disrupted the ability to process horizontal information in MSF and HSF ranges. This finding was replicated even when task difficulty was equated across orientation and SF at upright orientation. Our findings suggest that upright face perception is tuned to horizontally oriented face information carried by intermediate and high SF bands. They further indicate that inversion alters the sampling of face information both in the orientation and SF domains. [less ▲]

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See detailScrambling horizontal face structure: behavioral and electrophysiogical evidence for a tuning of visual face processing to horizontal information
Goffaux, Valerie; Schiltz, Christine UL; Jacques, Corentin

Poster (2011, August)

Filtering faces to remove all but the horizontal information largely preserves behavioral signatures of face-specific processing, including the face inversion effect (FIE). Conversely, preserving only ... [more ▼]

Filtering faces to remove all but the horizontal information largely preserves behavioral signatures of face-specific processing, including the face inversion effect (FIE). Conversely, preserving only vertical information abolishes this effect. In contrast to previous studies which used filtering, the present studies manipulated orientation content of face images by randomizing Fourier phase spectrum in a narrow horizontal orientation band (H-randomization) or vertical orientation band (V-randomization). Phase-randomization was performed on face images in which spatial frequency amplitude spectrum (SF-AS) was either left unaltered or equalized across all SF orientations. We further investigated the time course of horizontal tuning using event-related potentials (ERP). We observed that (i) upright faces were best discriminated when the horizontal structure was preserved (ie V-randomization) compared to H-randomization; (ii) this phase-randomization effect was eliminated by inversion, resulting in (iii) a smaller FIE for H-randomized than V-randomized faces. This pattern was still present but was less consistent when SF-AS was equalized across SF orientations, suggesting that SF-AS in horizontal orientation contributes to the horizontal tuning of face perception. ERP evidence of horizontal tuning for upright face processing was observed in the N170 time-window, a well-known face-sensitive electrophysiological component. The N170 was delayed for H-randomized compared to V-randomized faces. Additionally, and in line with behavioural data, face inversion increased N170 latency to a smaller extent for H-randomized compared to V-randomized. Altogether, our findings indicate that horizontal tuning is a robust property of face perception that arises early in high-level visual cortex. [less ▲]

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See detailRelationships between number and space processing in adults with and without dyscalculia
Mussolin, Christophe; Martin, Romain UL; Schiltz, Christine UL

in Acta Psychologica (2011), 138

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding ... [more ▼]

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding atypical math development. Adults with a diagnosis of dyscalculia (DYS) during childhood were compared to adults with average or high abilities in mathematics across two bisection tasks. Participants were presented with Arabic number triplets and had to judge either the number magnitude or the spatial location of the middle number relative to the two outer numbers. For the numerical judgment, adults with DYS were slower than both groups of control peers. They were also more strongly affected by the factors related to number magnitude such as the range of the triplets or the distance between the middle number and the real arithmetical mean. By contrast, adults with DYS were as accurate and fast as adults who never experienced math disability when they had to make a spatial judgment. Moreover, number–space congruency affected performance similarly in the three experimental groups. These findings support the hypothesis of a deficit of number magnitude representation in DYS with a relative preservation of some spatial mechanisms in DYS. Results are discussed in terms of direct and indirect number–space interactions. [less ▲]

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See detailInteractions between number and space processing in adults with dyscalculia
Mussolin, Christophe; Schiltz, Christine UL

Poster (2011, May 27)

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding ... [more ▼]

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding atypical math development. Adults with a diagnosis of dyscalculia (DYS) during childhood were compared to adults with average or high abilities in mathematics across two bisection tasks. Participants were presented with Arabic number triplets and had to judge either the number magnitude or the spatial location of the middle number relative to the two outer numbers. For the numerical judgment, adults with DYS were slower than both groups of control peers. They were also more strongly affected by the factors related to number magnitude such as the range of the triplets or the distance between the middle number and the real arithmetical mean. By contrast, adults with DYS were as accurate and fast as adults who never experienced math disability when they had to make a spatial judgment. Moreover, number-space congruency affected performance similarly in the three experimental groups. These findings support the hypothesis of a deficit of number magnitude representation in DYS with a relative preservation of some spatial mechanisms in DYS. Results are discussed in terms of direct and indirect number-space interactions. [less ▲]

Detailed reference viewed: 51 (0 UL)
See detailFace Perception: fMRI and Prosopagnosia
Schiltz, Christine UL

Presentation (2011, May 17)

Detailed reference viewed: 47 (1 UL)
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See detailContribution of Spatial Frequency and Orientation to upright and inverted face perception
Goffaux, Valerie; Van Zon, Jaap; Hestermann, Dietmar et al

Poster (2011, May)

It was recently shown that expert face perception relies on the extraction of horizontally oriented visual cues. Picture-plane inversion was found to eliminate horizontal, suggesting that this tuning ... [more ▼]

It was recently shown that expert face perception relies on the extraction of horizontally oriented visual cues. Picture-plane inversion was found to eliminate horizontal, suggesting that this tuning contributes to the specificity of face processing. The present experiments sought to determine the spatial frequency (SF) scales supporting the horizontal tuning of face perception. Participants were instructed to match upright and inverted faces that were filtered both in the frequency and orientation domains. Faces in a pair contained horizontal or vertical ranges of information in low, middle, or high SF (LSF, MSF, or HSF). Our findings confirm that upright (but not inverted) face perception is tuned to horizontal orientation. Horizontal tuning was the most robust in the MSF range, next in the HSF range, and absent in the LSF range. Moreover, face inversion selectively disrupted the ability to process horizontal information in MSF and HSF ranges. This finding was replicated even when task difficulty was equated across orientation and SF at upright orientation. Our findings suggest that upright face perception is tuned to horizontally oriented face information carried by intermediate and high SF bands. They further indicate that inversion alters the sampling of face information both in the orientation and SF domains. [less ▲]

Detailed reference viewed: 42 (0 UL)
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See detailScrambling horizontal face structure: behavioral and electrophysiogical evidence for a tuning of visual face processing to horizontal information
Jacques, Corentin; Schiltz, Christine UL; Collet, Kevin et al

Poster (2011, May)

Recent psychophysical evidence indicates that a central feature of human face processing is its tuning to horizontally-oriented information. Specifically, filtering faces to remove all but the horizontal ... [more ▼]

Recent psychophysical evidence indicates that a central feature of human face processing is its tuning to horizontally-oriented information. Specifically, filtering faces to remove all but the horizontal information largely preserves behavioral signatures of face-specific processing, including the face inversion effect (FIE). Conversely, preserving only vertical information abolishes these effects. The purpose of the present experiments was twofold. First, in contrast to previous studies which used filtering, we manipulated orientation content of face images by randomizing Fourier phase spectrum in a narrow horizontal orientation band (H-randomization) or vertical orientation band (V-randomization). Phase-randomization was performed on face images in which spatial frequency amplitude spectrum (SF-AS) was either left unaltered or equalized across all SF orientations. Second, we investigated the time course of tuning to horizontal information using event-related potentials (ERP). Picture-plane inversion was used to evaluate whether the effects of orientation of phase-randomization arise due to inherent stimulus properties or to face-specific perceptual biases. In two psychophysics experiments, we observed that (1) upright faces were best discriminated when the horizontal structure was preserved (i.e. V-randomization) compared to H-randomization. (2) This phase-randomization effect was eliminated by inversion, resulting in (3) a smaller FIE for H-randomized than V-randomized faces. Although this pattern was still present when SF-AS was equalized across SF orientations, it was less consistent, suggesting that SF-AS in horizontal orientation contributes to the horizontal tuning of face perception. Consistent ERP evidence of horizontal tuning for upright face processing was observed in the N170 time-window, a well-known face-sensitive electrophysiological component. The N170 was delayed for H-randomized compared to V-randomized faces. Additionally, and in line with behavioural data, face inversion increased N170 latency to a smaller extent for H-randomized compared to V-randomized faces. Altogether, our findings indicate that horizontal tuning is a robust property of face perception that arises early in high-level visual cortex. [less ▲]

Detailed reference viewed: 85 (0 UL)
Peer Reviewed
See detailShifts of spatial attention cued by irrelevant numbers: Electrophysiological evidence from a target discrimination task
Schuller, Anne-Marie UL; Hoffmann, Danielle UL; Schiltz, Christine UL

Poster (2011, April)

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects ... [more ▼]

Fischer et al. demonstrated that a centrally presented number can shift attention to the left/right when its magnitude is small/large. Two electrophysiological studies described these attentional effects as event-related potentials (ERPs) at centro-parietal sites. Since both studies used target detection tasks, it remains currently unknown whether similar results would be obtained with a discrimination task. We used ERPs to test whether digit cues also induce attention shifts when participants perform a feature-discrimination task on targets. ERPs were recorded whereas subjects discriminated the colour of lateral targets that were preceded by a central non-predictive digit. Analysis of cue-locked controlateral vs. ipsilateral ERP activity showed the emergence of early preparatory attention-directing components in parietal and frontal regions. Moreover, target-locked P1 components at occipito-parietal sites were significantly modulated by digit magnitude-target side congruency. These results demonstrate that irrelevant digit cues also bias sensory processing when embedded in a feature-discrimination task. [less ▲]

Detailed reference viewed: 91 (3 UL)
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See detailLongitudinal predictors of early mathematics: Number-specific versus domain-general mechanisms?
Hornung, Caroline UL; Brunner, Martin; Schiltz, Christine UL et al

Poster (2011, February 11)

Longitudinal predictors of early mathematics: Number-specific versus domain-general mechanisms? What is a good basis for developing mathematical competencies? While some authors propose that number ... [more ▼]

Longitudinal predictors of early mathematics: Number-specific versus domain-general mechanisms? What is a good basis for developing mathematical competencies? While some authors propose that number-specific abilities primarily contribute to early math development, other authors suggest that domain-general abilities are key. [less ▲]

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See detailWhen numbers act as attentional cues: behavioral and fMRI investigations
Goffaux, Valerie; Hoffmann, Danielle UL; Martin, Romain UL et al

Poster (2011, February 11)

Detailed reference viewed: 33 (1 UL)