Want to know something wild? Scientists don’t know why we hiccup. Everyone hiccups once in a while and we just cannot figure out why. In fact, pre-term babies spend an estimated 1% of their time hiccupping – that’s 15 wild minutes per day. But now a new UCL-led study could at least try explaining why that could be.
This study involved 13 newborn infants in a neonatal ward. All of them had bouts of hiccups, which is completely normal and nothing to worry about. Scientists recorded their brain activity with EEG (electroencephalography) electrodes placed on the scalp. This non-invasive method allows researching the brain without even disturbing the baby too much. Scientists also recorded body movements of these infants to know when exactly they are hiccuping.
Scientists notices that every hiccup results in three waves travelling across the cortex. The third one is the weakest one and is similar to that evoked by a noise. This makes scientists think that this is actually how newborns are calibrating their bodies – brains are registering how contractions of the diaphragm muscle feel and sound like. This eventually leads to a better control of the breathing function, which is incredibly important for speech and survival. It could also help developing other neural circuits, necessary for gaining normal control over regular bodily functions.
Research associate Kimberley Whitehead, one of the authors of the study, said: “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”.
In the early life stages humans are learning how to use their bodies. For example, infants are spending a lot of time just looking at their own fingers trying to move them. They are also watching adults and experimenting a lot. They are checking, which muscle does what. This is how they are basically learning the function of each muscle. Or at least that’s what we think.
Adults do hiccup a lot too though. This, as scientists said, could be a vestigial reflex, but it could also be some unknown reaction. Hopefully, scientists will soon figure out why people hiccup and will help those who simply cannot stop hiccuping. But for that more research is needed.