Structural changes

Synaptic pruning

• Universal process.

• The basis of human learning.

• Synaptic connections are eliminated.

• Neurons that are frequently used develop stronger connections, but those that are not used or are used very little will be. eliminated.

• Neural remodeling is essential for brain maturation.

Structure and composition of the cerebral cortex

• In the frontal lobes (related to executive functions): the increase in white matter

continues (earlier in women than in men).

• There is a reduction in grey matter through the pruning of dendritic connections that were not used during childhood → this increases the brain's efficiency (fewer neural connections but stronger, more homogeneous, and effective).

• It starts in the posterior areas of the brain and moves forward to the more anterior areas, reaching the prefrontal cortex by the end of adolescence.

Physical development of the brain

Cortical and Subcortical Systems:

Amygdala: It participates in emotional and instinctive reactions > more active in early adolescence.

Frontal lobes: They are associated with problem-solving, reasoning, goal setting, planning, emotional regulation, and impulse control (executive functions) > more active in late adolescence.

• This can explain the tendency to seek out emotions and novelty, as well as the difficulty in focusing on long-term goals.

Socioemotional network and Cognitive control network

The characteristic risk-seeking behaviour of adolescence appears to result from the interaction of two brain networks::

Socioemotional network:

• Sensitive to social and emotional stimuli (e.g., peer influence) → its

activity increases during puberty..

Cognitive control network:

• Regulates responses to stimuli → matures more gradually and over a

longer period of time.

• Due to the slow and extensive brain development during adolescence, it is highly susceptible to environmental influences, both positive and negative (e.g., drugs).

The importance of cognitive stimulation during adolescence → bidirectional impact.

• Activities and experiences determine which connections are preserved and strengthened.

• Strengthened connections in certain brain areas enable greater cognitive control over functions.