Somatosensory prediction in the premature neonate brain” project

5 senses for kids Foundation 2022 Scientific Research Award winning project in partnership with the Society for Neuroscience.

The research “Somatosensory prediction in the premature neonate brain” is led by Dr Victoria Dumont, post-doctoral researcher and psychologist. Non-profit public research.

COMETE Research Unit, UMR-S 1075 INSERM/UNICAEN
Pôle de Formation et de Recherche en Santé
2 rue des Rochambelles F-14032 CAEN Cedex 5

Scientific context of the project “Somatosensory prediction in the brain of premature newborns

• Prematurity (i.e. birth before 37 weeks of amenorrhea) concerns more than one birth in ten.
• These births occur during the 3rd trimester of gestation, which is an extremely important period of pregnancy, particularly because of the intensity of brain development during these last 3 months.
• Prematurity is a major developmental risk for newborns who leave the neonatal unit alive.
• 4 out of 10 premature babies have a disorder during childhood.
• These disorders associated with prematurity are numerous, affecting all spheres of development: cerebral, cognitive, motor, sensory, emotional, and social.
• There is an increased prevalence of atypical sensory profiles in these children, particularly in visual, auditory and tactile modalities. Follow-up studies also show an increased risk of neurodevelopmental disorders in childhood, such as Autism Spectrum Disorders and Attention Deficit Hyperactivity Disorder.
• These disorders are frequently associated with tactile processing peculiarities: these children may exhibit tactile defence behaviours(i.e. avoidance), or difficulties in habituation, i.e. filtering irrelevant sensory information.

Project issues

• Due to the risk factor of premature birth, the early environment and the associated sensory stimuli, particularly tactile, are increasingly incriminated in the occurrence of these disorders.
• Until now, little attention has been paid to the study of how preterm infants process tactile information. Yet touch is the most primitive form of connection to the external world: it is the first sense to appear during foetal development. Omnipresent at birth, it is on this fundamental sensory modality that the more distal modalities and cognition will subsequently develop (Rigato et al., 2017). In the context of preterm birth, newborns are subjected to mostly novel and maladaptive tactile information, very different from that of the uterine environment, both in terms of quality and quantity.
• The study of tactile processing in the neonatal period could be the key to understanding the origins of cognitive development and to find the first markers of neurodevelopmental vulnerability in these preterm newborns.

Project objectives

• We assume that touch is the first basis of learning and that the mechanisms of information processing implemented via this tactile input will condition the way in which the newborn will subsequently understand the stimuli produced by other types of sensoriality. However, in the context of developmental difficulties, sensory atypia and cognitive disorders are present in the same children.
• Moreover, these sensory atypia precede the symptoms that will be used to make a diagnosis of a neurodevelopmental disorder. In at-risk populations such as premature newborns, these disorders are four to five times more frequent, yet it is not yet known whether sensory atypia are the cause of cognitive disorders.
• The aim of the project was therefore to characterise these skills at birth. We assessed, 4 weeks before the equivalent age of term, the capacity of the brain of preterm newborns born between 31 and 32 weeks of amenorrhoea to process tactile stimulation (within the somatosensory cortex). We also wanted to evaluate their ability to anticipate(i.e. sensory prediction) repeated tactile stimulation according to the regularity of its presentation (either at identical or irregular intervals). Finally, we wanted to study their ability to habituate to tactile stimulation(i.e. suppression by repetition) by comparing the amplitude of the brain response during the 13-minute tactile stimulation protocol. The overall brain responses within the somatosensory cortex were assessed by Diffusion Spectroscopy (DCS), which involves sending low-intensity infrared light through the skull to measure the blood oxygen concentration that increases in response to neuronal activity. This tool has the advantage of being non-invasive and silent.
• This study started between 2016 and 2019.

Results and impacts of the project

• Our study has shown for the first time that preterm infants are already able to form sensory predictions: after several repetitions of the vibration, they expect it. When the intervals of tactile stimulation were the same, their brain stopped reacting to the stimulation because it was very predictable and neither painful nor pleasant: the brain ignored it and saved its resources for something else.
• In the case of irregular tactile stimuli, brain activity increases in the time interval when the tactile event is likely to occur, so attention remains focused on this likely but not completely predictable stimulation.

This work shows that preterm infants do not passively undergo their environment but will learn from their experiences and regulate their brain activity accordingly.

• We are currently investigating the prognostic value of these somatosensory prediction abilities at birth in this vulnerable population on their later neurocognitive development.
• To do so, we are including 90 preterm neonates born between 24 and 34 weeks of amenorrhoea. All newborns have an Electroencephalogram (EEG) and Near Infrared Spectroscopy (NIRS) during the tactile stimulation sequence before discharge.

For more information:

• Read more about the published article: Somatosensory prediction in the premature neonate brain – ScienceDirect

• About the other projects of 5 senses for kids Foundation