Aging changes how people view themselves and others through 'mind wandering', GUMC researchers have indicated.
Neuroscientists at Georgetown University Medical Center have shown why children and young adolescents veer toward the egocentric rather than the introspective.
In findings the researchers say that the five scattered regions in the brain that make up the default-mode network (DMN) have not started working in concert in youngsters aged six to nine. These areas light up in an fMRI scan, but not simultaneously.
The DMN is only active when the mind is at rest and allowed to wander or daydream. This network is believed to be key in how a person introspectively understands themselves and others, and forms beliefs, intentions, and desires through autobiographical memory.
By ages 10 to 12, the researchers found that these diffuse regions start functioning together as a unit, and at ages 13 to19, they acted in concert, just like they do in adults.
"These results suggest that children develop introspection over time as their brains develop," said the study's first author, neuroscientist Stuart Washington, who will be presenting the results.
"Before then they are somewhat egocentric, which is not to mean that they are negatively self-centered, but they think that everyone views the world in the same way they do. They lack perspective in that way."
Previous research has suggested that the DMN is not well synchronized in many autistic individuals, Washington said.
An example that illustrates the difference between an egocentric and an introspective view is the simple puzzle, Washington said: Jane" walks into a room, and puts a marble in a closet, and then "Bill" comes in and takes the marble out of the closet and puts it into a box. Jane comes back in and looks for the marble and she has not spoken to Bill. Where does she look for the marble?
The right answer, of course, is that she looks in the closet. But many autistic individuals say Jane looks in the box, "because they know that the marble is in the box and they think that everyone else knows that," Washington says.
The team gave the participants a task to perform, but the scientists were actually interested in recording brain activity that took place after the task was over, when the patients were told to rest.
In the group of children ages six to nine, the researchers saw the same kind of lack of synchronicity seen in older autistic children, Washington said.
The older participants in this study were, the more in sync the DMN functioned, reaching a plateau in adulthood, he said.
The study has been presented at the annual meeting of the Society for Neuroscience in San Diego.