The findings on how infants explore their environment using touch may represent a potential target for early intervention. New findings from researchers at Birkbeck, the University of East Anglia and the University of Cambridge show that the way babies’ brains respond to repeated touch predicts later behavioural features of autism in toddlerhood.
In most individuals, sensory stimuli, such as noises, textures or vibrations, activate parts of the brain devoted to the processing of sensory information. When the same sensation is repeated, the brain dampens its response, leading to a process called “habituation”. Habituation is a fundamental mechanism that enables the “filtering out” of unimportant sensations, such as the continuing sound of air conditioning whirring or the constant feeling of clothes on the skin. As such, habituation is essential to focusing on new sensory information and preventing senses getting overloaded. Children with autism or Attention-Deficit Hyperactivity Disorder (ADHD) often show signs of sensory overload, particularly when experiencing touch. As such, the researchers wanted to find out if the brain not dampening its response (decreased brain habituation) to repeated touch (tactile) stimuli predicts later behaviour characteristics of autism and ADHD, which may explain the frequent co-occurrence of these conditions.
Infant siblings of children with autism and/or ADHD (who are at elevated likelihood for the development of these conditions themselves) and infant siblings of children without the disorders were tested when they were 10 months of age. Brain responses were recorded whilst infants’ feet were stimulated with repeated pairs of gentle vibrations. The researchers also collected judgements from parents of the infants’ touch-related behaviours through a set of questionnaires. Measures of autistic and ADHD traits were then collected from the same participants when they were 24 months old. Results showed that the babies who later had more autism features in their behaviour, had reduced brain habituation to repeated touch when they were 10 months of age. Importantly, results from the study also indicated that those infants who explored their environment using touch despite their decreased habituation of brain responses developed fewer autistic traits at 24 months.
Elena Serena Piccardi, Research Fellow and Teaching Assistant at Birkbeck commented: “Sensory experiences in the first years of life are essential for infants to build a model of the world and themselves. Our research indicates not only that reduced habituation of brain responses in infancy predicts the extent of autism features in toddlerhood, but also that the way infants explore their environment using touch (also known as “tactile sensory seeking”) may represent a potential target for early intervention. “As part of our ongoing research, we are interested in characterizing individual differences in infants’ and children’s sensory seeking behaviours – whether children are active and engaged in their environment or not. Babies’ earliest learning happens through their senses. Thus, this research will help us understand why different children may prefer different sensory experiences, but also what experiences different children may need more of, and when and how to introduce them, so to best support their early learning.”
Dr. Teodora Gliga, Assistant Professor at the University of East Anglia, added: “Neurodevelopmental studies of autism have rarely investigated the perception of touch, in contrast with the frequent report of increased sensitivity to touch from individuals with autism. Given that this is associated with poor sleep and with eating difficulties in young children, studies such as ours may offer therapeutic insights into many of the symptoms associated with autism.” This research received funding from the UK Medical Research Council, the Wellcome Trust, the Innovative Medicine Initiative and the MQ Charity, and has been published in the Journal of Neurodevelopmental Disorders.
Source: Birkbeck, University of London