Sleep and Sensory Processing in Infants at Elevated and Typical Likelihood for Autism

De Laet, Anna (2024) Sleep and Sensory Processing in Infants at Elevated and Typical Likelihood for Autism. Doctoral thesis, University of East Anglia.

Preview

PDF Download (5MB) | Preview

Abstract

Undisturbed sleep is important at any age, but especially during development, when sleep is necessary for healthy brain maturation. However, during sleep, the brain continues to receive and process sensory input from the environment, awaking if necessary. The brain needs to achieve the right balance between processing sufficient input and protecting underlying processes from sensory disturbance. This thesis aims to understand the mechanisms that link disrupted sleep and sensory sensitivities, two symptoms that are common in autistic individuals, starting early in development. One potential reason why these symptoms often co-occur is that ineffective gating of sensory input disrupts sleep, though other reasons include sleep difficulties causing sensory issues, or both symptoms sharing an underlying cause. This thesis investigated whether there is support for a causal relationship from sensory processing differences to sleep difficulties, focussing on infancy. First we showed that an objective neural measure of sensory gating predicts sleep onset latency in 10 month-old infants, but not night awakenings (Chapter 2). A first indicator that poor gating of sensory input may drive at least some aspects of sleep difficulties. To further explore causality, we analysed a longitudinal secondary dataset with measurements of sensory profiles and sleep onset and maintenance at 5, 10 and 14 months in infants at typical and elevated likelihood for autism (Chapter 3). We examined the directionality of effects – whether sleep difficulties predict sensory differences or vice versa – but found no evidence for either. Instead we found that infants that woke up frequently at night tended to have heightened sensory profile across the course of the study, indicative of a common underlying mechanism driving both sleep and sensory profiles. Then we conducted an experimental study to assess the effect of sensory input on sleep and the interaction with sensory profiles (Chapter 5). We investigated sleep protective markers, such as slow waves and sleep spindles, and arousibility. Before doing so, we ensured that these measures could be reliably detected in our infant dataset by improving the performance of an automated algorithm originally designed for adults (Chapter 4). We found tentative evidence that sensory input during sleep disrupts sleep spindle production only in infants that are more hypersensitive. We also found that infants with heightened sensory profiles tended to have lower slow wave activity and higher arousal levels, irrespective of the sensory environment. These findings indicate that already early in development sleep and sensory processing are intertwined. We find more support for a common underlying mechanism driving both sleep and sensory differences, rather than sensory differences causing sleep difficulties.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Social Sciences > School of Psychology
Depositing User:	Chris White
Date Deposited:	17 Feb 2025 11:43
Last Modified:	17 Feb 2025 11:43
URI:	https://ueaeprints.uea.ac.uk/id/eprint/98513
DOI:

Downloads

Actions (login required)

View Item