THE brain undergoes changes in adolescence that suppress fearful experiences learned in childhood, said a study released on Monday that could explain why teenagers act so brashly at times.
Scientists studied the fear responses of mice for clues about how adolescents would react to situations that resembled prior experiences that involved pairing of electric shocks and tonal noises.
When they compared how adolescent mice showed a freeze reaction, compared to younger and older mice, they found that the teenagers did not freeze at the same rate, and that they were suppressing their reactions to contextual fear.
An examination of the brain activity in the adolescent mice showed that the two areas of the brain associated with processing experiences of fear - the basal amygdala and the hippocampus - were exhibiting lower levels of activity.
It wasn't that the teen mice failed to learn to be afraid, it was just that their brains weren't sending the same signals as the brains of baby or adult mice did.
While it might be exasperating for parents, the lack of fear response could prove useful because it comes at a time when adolescents are exploring and testing the bounds of their independence, which they could not do if they were paralysed by fear.
