Examining the Neural Correlates of Number Line Estimation in 4- to 6-Year-Old Children

• In Event: Breaking Barriers to Better Understand Early Cognitive Development: Novel Task-Based fMRI Paradigms in Young Children

Abstract

The number line estimation (NLE) task, in which participants indicate a numeral’s corresponding spatial location on a number line, is a robust predictor of mathematical competence (Schneider et al., 2018). Longitudinal developmental research suggests that, even prior to extensive formal math education, young children’s performance on the NLE task is predictive of both their concurrent and future calculation abilities (Berteletti et al., 2010; Gunderson et al., 2012). Although the NLE task is a commonly used measure of spatial-mathematical abilities, little is known about the neural mechanisms underlying the NLE task (Kanayet et al., 2017; Vogel et al., 2012). Moreover, despite many advances in developmental neuroimaging (Cantlon, 2020), there is no work to date using fMRI to evaluate the neural mechanisms of the NLE task in children. One possible reason for the limited work on this topic may be task-related motion. The NLE task typically requires that children mark their response on the number line using a pencil or a computer mouse. Thus, because fMRI is highly sensitive to even very small movements (>5mm), we designed a novel NLE-comparison task to minimize task-related motion. In this task, children (4 – 6 years old) indicated which, of two presented locations on the number line, was closer to the target numeral’s location. We found that children’s accuracy on this task was significantly correlated with their accuracy on a traditional NLE task, r(12) = .61, p = .02. Using task-based fMRI, we then evaluated the neural correlates of NLE. Children completed an independent localizer during which they viewed four different stimulus categories (faces, numerals, shapes, and words), presented in a block design. Number-specific areas were defined as areas that exhibited greater activation to numerals than the mean activation of the other three categories (faces, shapes, and words). During the experimental runs, children completed blocks of trials composed of either the NLE-comparison task or a color comparison task. We then asked whether the localized number-specific areas responded significantly more to the NLE-comparison blocks than the color comparison blocks. Preliminary analyses found significantly greater activation in the right intraparietal sulcus during the NLE task than the control color judgment task, corroborating similar work examining the neural correlates of the NLE task in adults (Vogel et al., 2012). The present findings provide initial validation of the use of the NLE-comparison task as both a behavioral and neural measure of number line estimation. Data collection is on-going, with at least 30 participants in the fMRI study, as well as an additional 30 participants in an otherwise identical study using functional near infrared spectroscopy (fNIRS), expected by the conference presentation. Additional analyses will examine the effects of age, gender, handedness, and behavioral math/spatial skills, on NLE-specific neural activation.

Authors

• Lauren Aulet, Carnegie Mellon University
  Presenting Author

• Jessica F. Cantlon, Carnegie Mellon University