A groundbreaking study from the University of East Anglia has unveiled new insights into the delicate nature of sleep among infants, particularly those with a heightened likelihood of developing autism. This research, published in the esteemed journal Sleep, explores how sensory sensitivity influences the quality and depth of sleep, revealing crucial neurological underpinnings that may help explain early developmental challenges seen in these children.
At its core, the study investigates the impact of environmental stimuli on infant sleep architecture, with a focus on deep, restorative sleep. Deep sleep, often identified by slow-wave activity in the brain, is vital for cognitive development and emotional regulation. By analyzing brainwave patterns captured via electroencephalography (EEG) during naps, researchers could discern that infants with increased sensory sensitivities exhibit shallower slow waves, indicating a compromised depth of sleep, even when the total duration remained unaffected.
In their experimental design, researchers enrolled 41 infants aged between eight and eleven months, stratifying participants based on familial risk factors for autism — specifically, whether an older sibling had an autism diagnosis. This approach allowed the team to capture a spectrum of sensory processing profiles. Each infant participated in two nap sessions: one in a quiet room and another in an environment punctuated with intermittent auditory stimuli roughly equivalent to the volume of normal conversational speech. This nuanced setup provided a controlled lens to observe how sensory input alters sleep dynamics in real-world contexts.
The data revealed that noisy environments significantly disrupted the deep sleep of infants with heightened sensory sensitivity. Surprisingly, even within quiet settings, these infants still demonstrated notably reduced slow-wave amplitude, suggesting an intrinsic neurophysiological difference in their sleep patterns that transcends external auditory interference. This phenomenon points to a form of sensory decoupling dysfunction during sleep, wherein the brain’s capacity to filter and dampen sensory input is less effective, compromising sleep quality.
Professor Teodora Gliga, who spearheaded the research at UEA’s School of Psychology, emphasized the novel understanding provided by these findings. “Our capacity to measure infants’ brainwaves during sleep illuminates how sensory processing differences manifest in early life, particularly affecting sleep depth,” she explained. “While it might appear that these infants sleep as long as others, the quality of that rest is fundamentally distinct, which could have profound implications for their neural development going forward.”
Such disruptions in sleep are not trivial. Deep sleep stages underpinned by robust slow-wave activity facilitate synaptic plasticity and memory consolidation, mechanisms that are particularly critical during infancy, a period marked by rapid brain growth and cognitive maturation. Shallow sleep may therefore exacerbate or reflect underlying neurodevelopmental vulnerabilities, underscoring why some infants at higher risk for autism face challenges not only in behavioral domains but also in fundamental physiological processes such as sleep.
Moreover, the study draws crucial attention to the interplay between an infant’s intrinsic sensory profile and extrinsic environmental factors. The fact that deep sleep was disrupted even in quiet conditions suggests that therapeutic approaches solely focused on minimizing environmental noise may not be sufficient. Instead, interventions might need to consider neurobiological mechanisms that enhance sensory gating — the brain’s ability to inhibit irrelevant sensory information during sleep — to improve overall sleep quality.
Dr. Anna de Laet, now a researcher at King’s College London and the study’s first author, highlighted the hereditary nature of autism and its associated sensory sensitivities. “By including infants with and without familial risk, we captured early sensory traits that precede diagnosable autism by years,” she noted. “These traits do not confirm an eventual diagnosis, but they reveal how fundamental sensory processing differences influence vital functions like sleep.”
The methodology employed sophisticated EEG monitoring to non-invasively assess infant brain activity during naturalistic sleep. The technical precision of these measurements allowed for the observation of subtle changes in slow-wave amplitude, a neurophysiological metric closely linked to sleep depth. This level of granularity had rarely been achieved in such young populations, positioning this study at the frontier of developmental neurophysiology and sleep research.
Families participating in the research contributed critical behavioral data through detailed questionnaires, enriching the neurophysiological findings with contextual insights into infants’ typical sensory behaviors. The integration of subjective parental reports with objective brain monitoring forms a comprehensive picture of how sensory sensitivities manifest in daily life and during periods of rest.
This work has broader implications beyond autism risk. Sensory sensitivities are common across various neurodevelopmental and mental health conditions, meaning that insights into sleep quality disruptions could inform intervention strategies for a wide array of children exhibiting atypical sensory processing. Understanding the neural basis of sensory decoupling during sleep might pave the way for novel therapies targeting the enhancement of sleep quality, which in turn could ameliorate cognitive and emotional outcomes.
Importantly, the study, funded by the Wellcome Trust, calls for expanded research into mechanisms that support sensory filtering during sleep and how these can be bolstered either through behavioral interventions or pharmacological means. Advancing this line of inquiry holds promise for improving the quality of life for sensitive infants and their families by addressing the foundational role sleep plays in neurodevelopment.
In summary, this pioneering investigation sheds light on the nuanced relationship between sensory processing and sleep integrity in infants at risk for autism. It highlights that the shallowness of deep sleep — rather than its duration — may be a critical biomarker of early neurodevelopmental divergence. These findings open new avenues for understanding and potentially mitigating sleep-related difficulties in neurodivergent populations from the earliest stages of life.
Subject of Research: People
Article Title: Sound asleep: Sensory decoupling during sleep depends on an infant’s sensory profile
News Publication Date: 20-Feb-2026
Web References: 10.1093/sleep/zsag010
Image Credits: Jenny Jones
Keywords: Autism, Sleep, Neurophysiology, Sensory stimuli, Cognitive development, Developmental disorders, Infants, Auditory perception
