The brains of babies "light up" in a similar way to adults when exposed to a painful stimulus, suggesting they feel pain much like adults do, a first of its kind study using MRI on infant pain has found.
The study by Oxford University researchers looked at 10 healthy infants aged between one and six days old and 10 healthy adults aged 23-36 years.
During the research, babies, accompanied by parents and clinical staff, were placed in a Magnetic Resonance Imaging (MRI) scanner where they usually fell asleep.
MRI scans were then taken of the babies' brains as they were 'poked' on the bottom of their feet with a special retracting rod creating a sensation 'like being poked with a pencil' - mild enough that it did not wake them up.
These scans were then compared with brain scans of adults exposed to the same pain stimulus.
The researchers found that 18 of the 20 brain regions active in adults experiencing pain were active in babies.
Scans also showed that babies' brains had the same response to a weak 'poke' as adults did to a stimulus four times as strong.
The findings suggest that not only do babies experience pain much like adults but that they also have a much lower pain threshold.
The researchers said that it is now possible to see pain 'happening' inside the infant brain and it looks a lot like pain in adults.
"Our study suggests that not only do babies experience pain but they may be more sensitive to it than adults," said Dr Rebeccah Slater of Oxford University's Department of Paediatrics, lead author of the report.
"We have to think that if we would provide pain relief for an older child undergoing a procedure then we should look at giving pain relief to an infant undergoing a similar procedure," said Slater.
"Recent studies in adults have shown that it is possible to detect a neurological signature of pain using MRI," Slater said.
"In the future we hope to develop similar systems to detect the 'pain signature' in babies' brains: this could enable us to test different pain relief treatments and see what would be most effective for this vulnerable population who can't speak for themselves," Slater added.
The research was published in the journal eLife.
