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Project

The role of third variables in the relationship between non-symbolic and symbolic numbers skills

Humans are endowed with the ability to extract and manipulate the numerical information present in the environment, commonly referred to as “number sense”. Evidence show that the number sense is an innate, evolutionary mechanism that allows to process approximate and non-symbolic numerical quantities (●●●). In addition, during their first years of life humans learn to operate with a symbolic systems for numbers, that includes notations such as number words (“three”) and Arabic digits (“3”). Children acquire the meaning of the number symbols, by linking them to the quantity they refer to (“three” corresponds to “●●●”). The symbolic numbers system subserve, later on, the acquisition of mathematical skills. How the ability of processing non-symbolic numbers relates to symbolic numbers knowledge and math skills is still a matter of debate. The purpose of the project presented here is to investigate the relationship between these two systems from a developmental perspective, with a focus on the role of other cognitive factors in determining the acquisition of symbolic numbers and math skills. With the first study, we aimed at delving into the methodology that is most commonly used to measure non-symbolic number processing: the numerosity comparison task. The performance in this task is classically interpreted as a pure index of approximate number system acuity (ANS acuity) and it is used to evaluate the level of maturation of this system during development. In Study 1, we designed two experiments with adults to evaluate the effect of the trials list composition, what we refer to as contextual factors, on the performance in the numerosity comparison. In Experiment 1 we demonstrated that the more complex is the pattern of covariation between numerical and non-numerical cues at the level of the global task, the more participants will rely on numerical ratios to solve the task; in Experiment 2 we showed that the accuracy in the numerosity comparison is affected when trials with easier or more difficult numerical ratios are added. We concluded that contextual factors should be taken into account when interpreting the results of a numerosity comparison task. [Attila Kr1] Studies 2 and 3 represent a first attempt to directly investigate the role of other cognitive factors on the relationship between non-symbolic and symbolic numbers knowledge (Study 2) and math skills (Study 3) in children. In Study 2, we measured in a sample of preschoolers (113 children, 2.5- to 4-years-old) non-symbolic numbers skills, symbolic number knowledge and inhibitory skills. The aim of this study is to demonstrate that inhibitory skills during this age range have a moderating role on the correlation found in literature between non-symbolic number skills and symbolic number knowledge. In Study 3, we tested a sample of 146 first graders with two versions of the numerosity comparison task; a standardized math test covering word problems skills, arithmetic fluency and procedural calculation; two tasks to assess inhibitory skills and a math anxiety test. Our aim is to investigate whether the relationship between non-symbolic number processing and math skills is impacted by a) the features of the tests employed for such measurements; b) inhibitory skills and c) math anxiety.

Date:1 Nov 2019 →  Today
Keywords:Numerical Cognition, Developmental Psychology
Disciplines:Behavioural neuroscience
Project type:PhD project