Tokyo: Children who are left without direct parental care for extended periods of time show larger gray matter volumes in the brain and may also show delay in brain development, according to a new study.
The researchers wanted to study children who are left in the care of relatives for a period of more than six months without direct parental care.
"Previous studies support the hypothesis that parental care can directly affect brain development in offspring. We looked at children who were left with relatives when the parents left to seek employment far from home," said study author Yuan Xiao from the Sichuan University in China.
MRI exams from 38 left-behind children (ages seven to 13) were compared to MRI exams from a control group of 30 children (ages seven to 14) living with their parents.
The researchers then compared the gray matter volume between the two groups and measured the intelligence quotient (IQ) of each participant to assess cognitive function.
They found larger gray matter volumes in multiple brain regions, especially in emotional brain circuitry, in the left-behind children compared to children living with their parents.
"Our study provides the first empirical evidence showing that the lack of direct parental care alters the trajectory of brain development in left-behind children," Xiao stated.
Since larger gray matter volume may reflect insufficient pruning and maturity of the brain, the negative correlation between the gray matter volume and IQ scores suggests that growing without parental care may delay brain development.
The study was presented recently at the annual meeting of the Radiological Society of North America (RSNA).