PAM Task 9 Teen brain
Learning goals:
1. Neurologic and behavioural development of adolescent brain
2. Problems with decision making
3. Implications for policy making
1. Neurologic and behavioural development of adolescent brain
The frontal lobes are home to key components of the neural circuitry underlying “executive
functions” such as planning, working memory, and impulse control and are not fully
developed until halfway through the second decade of life. Myelination in PFC not until 20s.
the neural connections between the amygdala (limbic structure for emotional processing) and
the cortices that compromise frontal lobes become denser during adolescence -> emotional
maturity.
3 robust changes in behavior for adolescents:
1. Increased novelty seeking
2. Increased risk taking
3. Social affiliation shift towards peers
Although the behaviors may lead to danger, they have an evolutionary advantage by
encouraging separation from the comfort and safety of the natal family to find a mate, which
decreases the chances of inbreeding, and to foster the development and acquisition of
independent survival skills.
In a task when having to ignore light, teenagers do this as good as adults but show much more
activity in frontal regions (involved in planning and executing actions) compared to adults.
The teen brain undergoes a major remodelling that may be responsible for their propensity to
take risks, seek out new experiences and fail to restrain inappropriate responses. Adolescents
are three or four times more likely to die than children past infancy because they take more
risks. Some (social/emotional) abilities keep maturing well into the twenties. The teenage
remodelling is analogous to the ‘developmental window’ that allows the brain to be molded
by experience in infancy.
By around the age of 12, a child’s brain has the size, folding, weight and regional
specialization of an adult’s, but it has a long way to go to reach adulthood.
White matter: The volume increases linearly with age, increasing less in females than in
males. The net increase across ages 4 to 22 was 12.4%. Did not significantly differ among
various lobes.
Grey matter: Changes in volume were nonlinear and regionally specific. Gray matter in the
frontal and parietal lobes increased during pre-adolescence with a maximum size occurring
between 10 and 12 years, followed by a decline during post-adolescence, however, pre- and
post-adolescent slopes were steeper for parietal than for frontal lobes. Temporal-lobe gray
matter also followed a nonlinear developmental course, but maximum size was not reached
until 16/17 years, with a slight decline thereafter. Occipital-lobe gray matter increased linearly
over the age range, without significant decline or leveling. The absolute size of the cortical
gray matter was approximately 10% larger in boys, and peaked slightly earlier in girls, but the
shapes of the curves were not significantly different between boys and girls. If the increase is
related to a second wave of overproduction of synapses, it may indicate a critical stage of
development when the environment or activities of the teenager may guide selective synapse
Learning goals:
1. Neurologic and behavioural development of adolescent brain
2. Problems with decision making
3. Implications for policy making
1. Neurologic and behavioural development of adolescent brain
The frontal lobes are home to key components of the neural circuitry underlying “executive
functions” such as planning, working memory, and impulse control and are not fully
developed until halfway through the second decade of life. Myelination in PFC not until 20s.
the neural connections between the amygdala (limbic structure for emotional processing) and
the cortices that compromise frontal lobes become denser during adolescence -> emotional
maturity.
3 robust changes in behavior for adolescents:
1. Increased novelty seeking
2. Increased risk taking
3. Social affiliation shift towards peers
Although the behaviors may lead to danger, they have an evolutionary advantage by
encouraging separation from the comfort and safety of the natal family to find a mate, which
decreases the chances of inbreeding, and to foster the development and acquisition of
independent survival skills.
In a task when having to ignore light, teenagers do this as good as adults but show much more
activity in frontal regions (involved in planning and executing actions) compared to adults.
The teen brain undergoes a major remodelling that may be responsible for their propensity to
take risks, seek out new experiences and fail to restrain inappropriate responses. Adolescents
are three or four times more likely to die than children past infancy because they take more
risks. Some (social/emotional) abilities keep maturing well into the twenties. The teenage
remodelling is analogous to the ‘developmental window’ that allows the brain to be molded
by experience in infancy.
By around the age of 12, a child’s brain has the size, folding, weight and regional
specialization of an adult’s, but it has a long way to go to reach adulthood.
White matter: The volume increases linearly with age, increasing less in females than in
males. The net increase across ages 4 to 22 was 12.4%. Did not significantly differ among
various lobes.
Grey matter: Changes in volume were nonlinear and regionally specific. Gray matter in the
frontal and parietal lobes increased during pre-adolescence with a maximum size occurring
between 10 and 12 years, followed by a decline during post-adolescence, however, pre- and
post-adolescent slopes were steeper for parietal than for frontal lobes. Temporal-lobe gray
matter also followed a nonlinear developmental course, but maximum size was not reached
until 16/17 years, with a slight decline thereafter. Occipital-lobe gray matter increased linearly
over the age range, without significant decline or leveling. The absolute size of the cortical
gray matter was approximately 10% larger in boys, and peaked slightly earlier in girls, but the
shapes of the curves were not significantly different between boys and girls. If the increase is
related to a second wave of overproduction of synapses, it may indicate a critical stage of
development when the environment or activities of the teenager may guide selective synapse
