The Prenatal Concept of number: Evidence of Visual Processing of Information before Birth

Dunn, Kirsty (2024) The Prenatal Concept of number: Evidence of Visual Processing of Information before Birth. In: XXIV ICIS 2024 Convergence, 2024-07-08 - 2024-07-11.

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Abstract

Much debate has surrounded the ontogeny of human understanding of the physical world, be this a capacity present at birth or, alternatively, learned through development and experience of the world, either passively or as a conscious construction of knowledge by the infant. This debate is well illustrated through the investigation of infants’ understanding of number. Many assume that establishing the presence of a number system in very young infants provides evidence for genetic underpinnings (e.g. Wynn, 1992). As with many visually assessed cognitive capacities though, the study of the development of numerical processing does not extend to prenatal research, primarily due to the technical complexities of delivering visual stimuli and measuring behavioural responses by foetuses. We consequently aimed to address the question of whether processing of number sets can be detected before birth using visual stimuli and methodology more akin to postnatal studies with controls developed in the infancy literature (e.g. Clearfield et al., 2001; Starkey et al., 1990). In the first sample, 88 foetuses were tested at 34 weeks gestation. Using a custom-made light source, sets of two and three dots were presented on alternate trials (order counterbalanced across the sample) for 45 seconds (fig. 1). Stimuli were held stationary for the trial to the periphery of the foetal face and light levels continually increased and decreased to control for variance in amount of luminance between conditions. This was then repeated for a second block, for a total of three minutes. Using 4D ultrasound, foetal head movements related to the visual stimuli were measured (fig. 2). Foetuses were excluded where good-quality imaging could not be obtained. In the final sample, 43 fetuses turned significantly longer towards than away from the 2-dots display, Wilcoxon rank, z = 2.309, p = 0.021 (fig. 3). However, they showed no difference in preference for turning towards compared with away from three dots. Results are consistent with those reported in neonatal research indicating differential attention to number sets (Coubart et al, 2014). In a second sample of 71 foetuses, behavioural coding is currently underway to compare foetal looking in the same paradigm to 1- compared to 2- dot number sets. This work provides evidence for the utility of applying postnatal visual experimental techniques to a prenatal sample when coupled with ultrasound behavioural measures. Further, this work indicates an emerging concept of number before birth and before postnatal experience. In this poster we explore the potential contributions of both genetics and prenatal experience on development.