Hiccuping is something we all experience and while we typically associate the uncomfortable reflex with digestive issues or reflux, there could be another reason why we hiccup.
A new study in the journal Clinical Neurophysiology took brain scans of infants and found that hiccups, caused by sudden contractions of the diaphragm muscle, could be vital in the development of newborn brains.
Neuroscientists, from University College London (UCL), discovered that each time a newborn baby hiccups, it triggers a wave of brain signals which could help the baby learn how to regulate their breathing.
“The reasons for why we hiccup are not entirely clear, but there may be a developmental reason, given that foetuses and newborn babies hiccup so frequently,” lead author of the study, Kimberley Whitehead, explained.
Pre-term infants, babies who are born more than three weeks before the due date, are particularly prone to hiccups as they spend approximately 1% of their time, around 15 minutes a day, hiccuping.
And as many pregnant women will also testify hiccuping can also happen while babies are still in the womb, sometimes as early as nine weeks into the pregnancy.
READ MORE: What actually causes hiccups?
For the study, researchers looked at the brain scans of 13 pre-term and full-term babies, ranging from 30 to 42 weeks gestational age.
Brain activity was recorded with electrodes attached to the scalp, while hiccuping movements were monitored with sensors on the babies’ torso.
The research suggests the contractions of the hiccups teach the baby's brain to monitor its ventilation muscles so that breathing can eventually be controlled voluntarily by moving the diaphragm up and down.
“The activity resulting from a hiccup may be helping the baby's brain to learn how to monitor the breathing muscles so that eventually breathing can be voluntary controlled by moving the diaphragm up and down,” said the study’s senior author, Dr Lorenzo Fabrizi, from UCL Neuroscience, Physiology & Pharmacology.
“When we are born, the circuits which process body sensations are not fully developed, so the establishment of such networks is a crucial developmental milestone for newborns,” he continued.
Although the cause of hiccups in adults still remains a bit of a mystery, certain things like stress, excitement or eating and drinking can trigger the muscle contraction, but the findings of the research prompted study authors to consider whether adult hiccups could also be a reflex, which is left over from infancy.
“Our findings have prompted us to wonder whether hiccups in adults, which appear to be mainly a nuisance, may in fact by a vestigial reflex, left over from infancy when it had an important function,” Kimberley Whitehead added.