Children often confront their parents over some or the other issue. Perhaps scientists have now found out why kids show such behaviour.
Researchers at Washington University and Oregon Health and Science University suggest that children's brains are organised differently than adults'.
However, the same study also provides parents with a rejoinder: hile the overarching organization scheme differs, one of the most important core principals of adult brain organization is present in the brains of children as young as 7.
"Regardless of how tempting it might be to assume otherwise, a normal child's brain is not inherently disorganized or chaotic. It's differently organized but at least as capable as an adult brain," says senior author Dr. Steven E. Petersen, the James McDonnell Professor of Cognitive Neuroscience at Washington University School of Medicine in St. Louis.
Scientists previously revealed four brain networks with varying responsibilities in the adult brain. Two of those networks appear to be co-captains in charge of most voluntary brain function. The networks typically involve tight links between several brain regions that are physically distant from each other.
In the new study, this is where the organizational contrast arises. The researchers observed that instead of having networks made of brain regions that are distant from each other but functionally linked, most of the tightest connections in a child's brain are between brain regions that are physically close to each other.
Lead researchers Dr. Damien A. Fair, a former Washington University graduate student who is now associated with Oregon Health and Science University, and Alexander L. Cohen, a current Washington University graduate student, directed analysis of data from 210 subjects ranging from 7 to 31 years old.
"We took a group of the youngest subjects, analysed their results, then dropped data from the youngest and added data from the next-oldest and redid the analysis until we had worked our way through all subjects. The result was a detailed movie of how the organizational transition from a child's brain to an adult's brain takes place. It clearly shows a switch from localized networks based on physical proximity to long-distance networks centred on functionality," Fair says.
Scientists already knew that children had many fewer long-distance links among brain regions than adults, but when they looked more closely, they found there were enough of these links and nodes with multiple connections to establish small-world organization.
The researchers set the lower limit for study subjects at 7 years of age because the brain is approximately 95 percent of its adult size at this age, but they are currently examining ways to adapt the study to the changing physical geography of younger brains.
They have also begun looking at the same phenomena in subjects with brain injuries and developmental disorders.
The study has been published online in PLoS Computational Biology.