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Magnitude representations in Williams syndrome: differential acuity in time, space and number processing.

Rousselle L, Dembour G, Noël MP - PLoS ONE (2013)

Bottom Line: Participants with WS showed lower acuity (manifested by a higher Weber fraction) than their verbal matched peers when processing numerical and spatial but not temporal magnitudes, indicating that they do not present a domain-general dysfunction of all magnitude processing.Conversely, they do not differ from non-verbal matched participants in any of the three tasks.Finally, correlational analyses revealed that non-numerical and numerical acuity indexes were both related to the first mathematical acquisitions but not with later arithmetical skills.

View Article: PubMed Central - PubMed

Affiliation: Center of Cognitive Neurosciences, Psychological Sciences Research Institute, Catholic University of Louvain, Louvain-la-Neuve, Belgium.

ABSTRACT
For some authors, the human sensitivity to numerosities would be grounded in our ability to process non-numerical magnitudes. In the present study, the developmental relationships between non numerical and numerical magnitude processing are examined in people with Williams syndrome (WS), a genetic disorder known to associate visuo-spatial and math learning disabilities. Twenty patients with WS and 40 typically developing children matched on verbal or non-verbal abilities were administered three comparison tasks in which they had to compare numerosities, lengths or durations. Participants with WS showed lower acuity (manifested by a higher Weber fraction) than their verbal matched peers when processing numerical and spatial but not temporal magnitudes, indicating that they do not present a domain-general dysfunction of all magnitude processing. Conversely, they do not differ from non-verbal matched participants in any of the three tasks. Finally, correlational analyses revealed that non-numerical and numerical acuity indexes were both related to the first mathematical acquisitions but not with later arithmetical skills.

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Related in: MedlinePlus

Accuracy data as a function of the ratio.Each panel respectively shows the percentage of correct responses as a function of the ratio in the numerical (A), spatial (B) and temporal (C) comparison tasks presented with logistic regression curves.
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pone-0072621-g002: Accuracy data as a function of the ratio.Each panel respectively shows the percentage of correct responses as a function of the ratio in the numerical (A), spatial (B) and temporal (C) comparison tasks presented with logistic regression curves.

Mentions: As displayed in Figure 2, participants’ performance varied as a function of the ratio between the magnitudes to be compared. In order to assess the precision of the underlying magnitude representations, the Weber fraction (w) was estimated individually from the participants’ correct responses in each task. There are several ways to define a Weber fraction and the approach taken here is the one inspired by Pica et al. [74] and Halberda and Feigenson [73] (see Supplement S1 for an extensive description of the Weber fraction estimation method). As our group samples were extremely disparate in terms of chronological and developmental age, it was important to compare each WS participant to his own verbal matched control. Such paired comparison was not possible using an analysis of variance model. Therefore, Weber fraction were analysed separately in each task using paired-sample T-tests.


Magnitude representations in Williams syndrome: differential acuity in time, space and number processing.

Rousselle L, Dembour G, Noël MP - PLoS ONE (2013)

Accuracy data as a function of the ratio.Each panel respectively shows the percentage of correct responses as a function of the ratio in the numerical (A), spatial (B) and temporal (C) comparison tasks presented with logistic regression curves.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3755976&req=5

pone-0072621-g002: Accuracy data as a function of the ratio.Each panel respectively shows the percentage of correct responses as a function of the ratio in the numerical (A), spatial (B) and temporal (C) comparison tasks presented with logistic regression curves.
Mentions: As displayed in Figure 2, participants’ performance varied as a function of the ratio between the magnitudes to be compared. In order to assess the precision of the underlying magnitude representations, the Weber fraction (w) was estimated individually from the participants’ correct responses in each task. There are several ways to define a Weber fraction and the approach taken here is the one inspired by Pica et al. [74] and Halberda and Feigenson [73] (see Supplement S1 for an extensive description of the Weber fraction estimation method). As our group samples were extremely disparate in terms of chronological and developmental age, it was important to compare each WS participant to his own verbal matched control. Such paired comparison was not possible using an analysis of variance model. Therefore, Weber fraction were analysed separately in each task using paired-sample T-tests.

Bottom Line: Participants with WS showed lower acuity (manifested by a higher Weber fraction) than their verbal matched peers when processing numerical and spatial but not temporal magnitudes, indicating that they do not present a domain-general dysfunction of all magnitude processing.Conversely, they do not differ from non-verbal matched participants in any of the three tasks.Finally, correlational analyses revealed that non-numerical and numerical acuity indexes were both related to the first mathematical acquisitions but not with later arithmetical skills.

View Article: PubMed Central - PubMed

Affiliation: Center of Cognitive Neurosciences, Psychological Sciences Research Institute, Catholic University of Louvain, Louvain-la-Neuve, Belgium.

ABSTRACT
For some authors, the human sensitivity to numerosities would be grounded in our ability to process non-numerical magnitudes. In the present study, the developmental relationships between non numerical and numerical magnitude processing are examined in people with Williams syndrome (WS), a genetic disorder known to associate visuo-spatial and math learning disabilities. Twenty patients with WS and 40 typically developing children matched on verbal or non-verbal abilities were administered three comparison tasks in which they had to compare numerosities, lengths or durations. Participants with WS showed lower acuity (manifested by a higher Weber fraction) than their verbal matched peers when processing numerical and spatial but not temporal magnitudes, indicating that they do not present a domain-general dysfunction of all magnitude processing. Conversely, they do not differ from non-verbal matched participants in any of the three tasks. Finally, correlational analyses revealed that non-numerical and numerical acuity indexes were both related to the first mathematical acquisitions but not with later arithmetical skills.

Show MeSH
Related in: MedlinePlus