Washington, Mar 29 : A new study has confirmed what many parents have believed till now - that their teenage offspring's brain is very much different from those of children and adults.
According to a new research, which used MRI to examine the brains of volunteers, natural changes in adolescents' brains affect their cognition, emotion and behaviour.
The researchers found that brain gray matter increases in volume until the early teens, then decreases until old age.
The data for the research was based on the NIMH Longitudinal Brain Imaging Project, which began in 1989.
Participants visit the NIMH at approximately two-year intervals for brain imaging, neuropsychological and behavioral assessment and collection of DNA.
As of September 2007, approximately 5000 scans from 2000 subjects have been acquired. Of these, 387 subjects, aged 3 to 27 years, have remained free of any psychopathology and served as the models for typical brain development.
From the analysis, three themes emerged. The first is functional and structural increases in connectivity and integrative processing as distributed brain modules become more and more integrated.
Using a literary metaphor, maturation would not be the addition of new letters but rather of combining earlier formed letters into words, and then words into sentences and then sentences into paragraphs.
The second is a general pattern of childhood peaks of gray matter (frontal lobe, parietal lobe, temporal lobe and occipital lobe) followed by adolescent declines. As parts of the brain are overdeveloped and then discarded, the structure of the brain becomes more refined.
The third theme is a changing balance between limbic/subcortical and frontal lobe functions that extends well into young adulthood as different cognitive and emotional systems mature at different rates.
The cognitive and behavioral changes taking place during adolescence may be understood from the perspective of increased "executive" functioning, a term encompassing a broad array of abilities, including attention, response inhibition, regulation of emotion, organization and long-range planning.
"Adolescence is a time of substantial neurobiological and behavioral change, but the teen brain is not a broken or defective adult brain. The adaptive potential of the overproduction/selective elimination process, increased connectivity and integration of disparate brain functions, changing reward systems and frontal/limbic balance, and the accompanying behaviors of separation from family of origin, increased risk taking, and increased sensation seeking have been highly adaptive in our past and may be so in our future," said Dr. Jay N. Giedd, MD of the National Institute of Mental Health (NIMH).
"These changes and the enormous plasticity of the teen brain make adolescence a time of great risk and great opportunity," he added.
The study 'The Teen Brain: Insights from Neuroimaging' is published in the Journal of Adolescent Health.