Grant: Discovery Grants Program - Individual

From calculating a monthly grocery budget to solving differential equations in high school, numbers are pervasive in all facets of our personal and professional lives. The overarching theme of my NSERC-supported research program is to combine behavioural and brain-imaging methods to investigate the development of foundational numerical skills. We share with other species an ability to process the numerical value of sets of items (e.g., that there are approximately 10 apples in a fruit basket). This ability to process numerical information without reference to a symbol (e.g., "10") is referred to as `non-symbolic' number processing. In contrast, numerical symbols (e.g., Arabic numerals and number words) are uniquely human and are learnt over child development. While it may seem intuitive that symbolic number development should be influenced by the pre-existing non-symbolic number processing ability, we have shown it is children's development of symbolic number processing that influences changes in non-symbolic number processing rather than vice-a-versa. These findings raise the question of how the development of symbolic number influences the way in which non-symbolic representations of number are processed? We predict that children's developing symbolic number processing skills allows them to focus on the number of items in a set, thereby reducing the influence of distracting characteristics of the set, such as the area it occupies, its density etc. We will test this hypothesis using a longitudinal research design in which children will be followed from age 5-8 years. Using behavioral and neuroimaging methods, we will estimate the influence of symbolic and non-symbolic number-processing on each other over time and examine how symbolic number development increases the ability to focus on numerical sets in the world. This work will enhance our understanding of how culture and learning shapes and changes inborn skills. It has been posited that non-symbolic number processing tasks, such as comparing which of two dot arrays contains more dots, reflect an underlying Approximate Number System (ANS). However, researchers have used a variety of different tasks to measure the ANS. Do all of these non-symbolic number processing tasks measure the same thing? Rather than making this assumption, we will probe the degree to which there does exist a common underlying construct (latent variable). We will do so in both children and adults to better understand developmental similarities and differences in relationships between non-symbolic tasks and the ANS. This work could impact the design of early numeracy screening tools. Together, these investigations will advance our understanding of the developmental dynamics underlying number processing and its measurement. In addition, the resulting data have the potential to impact early numeracy screening and to facilitate children's numerical development through the design of evidence-based tools.