Summary: For babies with a higher likelihood of autism, \u201cquiet\u201d might not be quiet enough. A new study reveals that infants with high sensory sensitivity struggle to achieve deep, restorative sleep\u2014even in peaceful environments.<\/p>\n
By monitoring brainwaves, researchers found that while these babies spend the same amount of time in \u201cdeep sleep\u201d as others, the quality of that sleep is significantly shallower. Their brain\u2019s slow waves are weaker, indicating a failure to fully \u201cdecouple\u201d from the sensory world. This discovery helps explain why neurodivergent infants are often \u201ceasily bothered\u201d and provides a new lens for supporting early brain development.<\/p>\n
Key Facts<\/p>\n
Shallower Deep Sleep: Highly sensitive infants have smaller and weaker slow waves during deep sleep, meaning their rest is less restorative even if the duration is normal.Sensory Decoupling Failure: Most brains \u201cshut out\u201d the world during deep sleep. In sensitive infants, the brain remains partially reactive to external sounds, like gentle beeps.Impact of Noise: When napping in even moderately noisy environments, the deep sleep of these infants is considerably more disrupted than that of their less-sensitive peers.Early Predictor: Sensory sensitivity is a common trait in neurodivergent infants and often emerges well before a formal autism diagnosis (which typically happens around age three).Beyond Noise Reduction: While a quiet room helps, these infants still experience shallower sleep in perfect silence, suggesting an internal \u201cwiring\u201d difference in how they process sensory input.<\/p>\n
Source: University of East Anglia<\/p>\n
Babies with an increased likelihood of autism may struggle to settle into deep, restorative sleep, according to a new study from the University of\u00a0East\u00a0Anglia.<\/p>\n
Researchers\u00a0studied\u00a0the link between sleep and\u00a0sensory sensitivity,\u00a0which is common in\u00a0neurodivergent\u00a0infants.<\/p>\n
They found that\u00a0when\u00a0babies with this trait napped in a noisy environment, their deep sleep was considerably disrupted.<\/p>\n
But even in a quiet room,\u00a0those\u00a0with high sensory sensitivity\u00a0still slept more lightly\u00a0\u2013\u00a0suggesting that both their\u00a0unique\u00a0sensory wiring and their surroundings\u00a0influence how well they rest.<\/p>\n
The work reveals important clues\u00a0about why some babies,\u00a0especially those who are highly sensitive to sensory\u00a0input, are\u00a0more likely to\u00a0struggle to\u00a0achieve\u00a0restorative sleep.<\/p>\n
Prof Teodora Gliga,\u00a0from UEA\u2019s School of Psychology,\u00a0who\u00a0led the study,\u00a0said:\u00a0\u201cMany parents tell us their baby seems \u2018easily bothered\u2019 by sounds or sensations\u00a0and we are now beginning to see how that sensitivity can affect their sleep.<\/p>\n
\u201cBy monitoring babies\u2019 brainwaves, we could see clear differences in how deeply\u00a0infants\u00a0slept in response to sound.<\/p>\n
\u201cMore sensitive infants didn\u2019t spend less time in deep sleep\u00a0\u2013\u00a0their deep sleep was simply shallower. The slow waves that define this stage were smaller and weaker, showing that while the duration was similar, the depth and quality of their sleep were reduced.<\/p>\n
\u201cOur results show that even everyday sounds can make it harder for some babies to stay in deep sleep, especially those with naturally heightened sensory responses.\u201d<\/p>\n
Some babies in the study were at higher likelihood of developing autism, not because they show diagnosable features at such a young age, but because they have an older autistic sibling.<\/p>\n
How the research happened<\/p>\n
Dr\u00a0Anna de Laet, first author on the study,\u00a0and now at King\u2019s College London,\u00a0said: \u201cAutism is a highly heritable condition. We included infants both with and without an older autistic sibling to capture a wide range of sensory sensitivities, which are common in autism and emerge early in development, often well before a diagnosis is possible.<\/p>\n
\u201cThese sensitivity traits don\u2019t mean a baby will develop autism, which we can\u2019t diagnose reliably before the age of three, but they help us study how early sensory differences might shape sleep in infancy.\u201d<\/p>\n
To understand these patterns, families visited the UEA sleep lab,\u00a0where each baby completed two naps\u00a0\u2013\u00a0one in a quiet room and one in a room where gentle beeps, about as loud as a normal conversation,\u00a0were played every few seconds.<\/p>\n
Researchers recorded babies\u2019 brain activity during sleep and compared sleep depth between the two conditions.<\/p>\n
Parents also completed questionnaires about their baby\u2019s typical behaviours and sensory sensitivities, which could be linked to their sleep quality.<\/p>\n
A total of\u00a041 babies between\u00a0eight\u00a0and\u00a011 months contributed to the data for the final analysis.<\/p>\n
Good sleep \u2018vital\u2019 for brain development<\/p>\n
Prof Gliga\u00a0said: \u201cReducing noise may help particularly sensitive babies, but it\u2019s not enough on its own. Their sleep was still shallower in quiet environments.<\/p>\n
\u201cGood sleep is vital for brain development and emotional well\u2011being, so understanding these differences is key to providing better support for families.\u201d<\/p>\n
The authors highlight the need for further research into how deep sleep might be better supported in these infants, potentially by strengthening the brain\u2019s ability to filter sensory input during sleep.<\/p>\n
Funding: This study was funded by Wellcome.<\/p>\n
\u2018Sound asleep: Sensory decoupling during sleep depends on an infant\u2019s sensory profile\u2019\u00a0is published in the journal\u00a0Sleep.<\/p>\n
Additional collaborators:\u00a0Prof\u00a0Rachael Bedford, Queen Mary\u00a0University of London\u00a0and\u00a0Dr\u00a0Alpar Lazar, UEA.<\/p>\n
Key Questions Answered:Q: My baby wakes up at every little sound\u2014does this mean they have autism?<\/p>\n
A: Not necessarily. Sensory sensitivity is a trait that can be linked to autism, but it also exists in many neurotypical children. This study looked at infants with autistic siblings to understand the hereditary nature of these patterns, but sensitivity alone is just one piece of a much larger developmental puzzle.<\/p>\n
Q: Can I \u201cfix\u201d my baby\u2019s shallow sleep with a white noise machine?<\/p>\n
A: Reducing noise is a great first step, but the study found that sensitive babies still had shallower sleep in quiet rooms. The goal for future research is to find ways to help the brain \u201cstrengthen\u201d its ability to filter sensory input during sleep.<\/p>\n
Q: Why is deep sleep so important for infants?<\/p>\n
A: Deep sleep is the \u201cclean-up and filing\u201d phase for the brain. It\u2019s vital for memory consolidation, emotional regulation, and overall brain development. If sleep is consistently shallow, it can affect how a baby processes the world when they are awake.<\/p>\n
Editorial Notes:This article was edited by a Neuroscience News editor.Journal paper reviewed in full.Additional context added by our staff.About this autism and sleep research news<\/p>\n
Author: Jordan Bacon<\/a>
Source: University of Eas<\/a>t<\/a> Anglia<\/a>
Contact: Jordan Bacon \u2013 University of East Anglia
Image: The image is credited to Neuroscience News<\/p>\n