Understanding the Nature and Nuances of Spatial-Numerical Associations: Insights from Internal, External, and Neurophysiological Factors

The enduring link between numerical and spatial cognition suggests the presence of an intrinsic spatial-numerical association among many individuals, or an internal ‘mental number line’ with a tendency to associate small numbers with the left side of space and larger numbers with the right. The cognitive mechanisms, physiology and proposed innateness of spatial-numerical associations are consistently a topic of interest and contention for researchers as they attempt to uncover the functional significance of this internal number-space representation for wider mathematical performance. It cannot be denied that a great deal of variability as a result of individual factors is frequently observed in the presentation and salience of number-space mappings. An exploration of the potential malleability and differing internal representations of the mental number line as a function of these individual differences might offer new insights into how spatial-numerical information is represented and eventually, an updated perspective on its role in broader cognitive and mathematical processes. With the above in mind, the current dissertation aimed to understand the influence of internal emotional factors (particularly domain-specific anxieties) and external cognitive factors (particularly reading/writing habits) on the stability or flexibility in number space mappings. These concepts are explored in two separate behavioural studies implementing a fast-paced directional number-line estimation paradigm, reinforced across multiple conditions and iterations to tap into both numerical and overtly spatial mechanisms recruited during number-space mapping. Results communicate compelling dissociations in how internal (emotional) and external (cognitive) factors shape the direction and salience of number-space mapping in different populations. A further aim of the dissertation is to explore the neurophysiological underpinnings in potential variability in spatial-numerical associations based on the findings of the behavioural studies. An investigation using pupillometry uncovered covert shifts of spatial attention in response to numerical magnitudes across multiple axes with variances in salience, suggesting neurophysiological evidence of multiple or spatially dynamic presentations of number-space associations. Finally, an in-depth discussion of the findings is provided as they relate to avenues for future research conducted from the perspective of a dynamic or malleable number-space mapping system and implications for both behavioural and neurophysiological research, educational methods and intervention are explored.