TV violence linked to poor reasoning

Can television content affect a person's brain development and functioning? Yes, warns a new study.

Young adults who watched more violence on television showed indications of less mature brain development and poorer executive functioning, according to researchers from Indiana University's school of medicine.

"We found that the more violence a participant viewed on TV, the worse they performed on tasks of attention and cognitive control," said lead author Tom A. Hummer from Indiana University.

"On the other hand, the overall amount of TV watched was not related to performance on any executive function tests," he added.

The study was done on 65 healthy males with normal IQ and aged between 18 and 29.

Participants completed a series of psychological tests measuring inhibitory control, attention and memory.

After the conclusion of the tests, MRI scans were used to map brain structure.

Executive function is the ability to formulate plans, make decisions, reason and solve problems, regulate attention, and inhibit behaviour in order to achieve goals.

"When we looked at the brain scans of young men with higher violent television exposure, there was less volume of white matter connecting the frontal and parietal lobes, which can be a sign of less maturity in brain development," he said.

White matter is the tissue in the brain that insulates nerve fibres connecting different brain regions, making functioning more efficient.

In typical development, the amount or volume of white matter increases as the brain makes more connections until about age 30, improving communication between regions of the brain.

Connections between the frontal and parietal lobes are thought to be especially important for executive functioning.

The study was published online in the journal Brain and Cognition.