Summary of Argument

Proposition of Law of Amici Curiae: Courts may take account of scientific evidence about adolescent brain development when addressing constitutional limitations on juvenile sentencing. The human brain undergoes significant structural, functional, and chemical changes during adolescence. Significant changes in brain structure take place during adolescence including synaptic pruning and myelination. Significant changes in brain function take place during adolescence. These changes involve functional brain maturation and executive function, functional brain maturation and reward processing, and functional brain maturation and socio-emotional cognition. Significant changes in brain chemistry related to reward processing take place during adolescence.

Summary of Argument

The proposition of law presented by the amici curiae argues that courts should consider the scientific evidence surrounding adolescent brain development when determining constitutional limitations on juvenile sentencing. The argument rests on the premise that the human brain undergoes substantial structural, functional, and chemical transformations during adolescence, impacting decision-making, impulse control, and risk assessment.

Significant structural changes occur within the adolescent brain, including synaptic pruning, the elimination of unused neural connections, and myelination, the process of forming myelin sheaths around nerve fibers, which improves signal transmission. These structural modifications contribute to the brain's ongoing development and refinement.

Functionally, the adolescent brain experiences notable changes in executive function, reward processing, and socio-emotional cognition. Executive function, encompassing planning, decision-making, and self-regulation, continues to mature throughout adolescence. Reward processing, the brain's response to pleasurable stimuli, exhibits heightened sensitivity in adolescents compared to adults. Furthermore, socio-emotional cognition, the ability to understand and manage emotions, undergoes significant development during this period.

In terms of brain chemistry, adolescence is characterized by alterations in reward processing systems, particularly those involving dopamine, a neurotransmitter associated with pleasure and motivation. These chemical changes contribute to adolescents' heightened susceptibility to reward and their potential for impulsive behaviors.

Summary of Argument

The argument presented proposes that courts should consider scientific evidence regarding adolescent brain development when determining constitutional limits on juvenile sentencing. It highlights the significant structural, functional, and chemical changes that occur in the brain during adolescence.

During adolescence, the brain undergoes significant structural changes, including synaptic pruning and myelination. Synaptic pruning eliminates unnecessary connections, while myelination strengthens existing connections, enhancing efficiency and speed.

Significant functional changes also occur during adolescence. These include:

• Functional Brain Maturation and Executive Function: This involves the development of self-control, planning, and decision-making abilities.

• Functional Brain Maturation and Reward Processing: Adolescents experience heightened sensitivity to reward and risk, which can influence impulsive behavior.

• Functional Brain Maturation and Socio-Emotional Cognition: The ability to understand and regulate emotions, as well as navigate social situations, continues to develop throughout adolescence.

Adolescence also sees significant changes in brain chemistry, particularly related to reward processing. These changes can explain why adolescents may be more prone to impulsive behavior and risk-taking.

Summary of Argument

The argument presented is that judges should consider scientific evidence about how adolescent brains develop when deciding on punishments for young offenders. This argument is based on the fact that the human brain continues to change and mature significantly throughout adolescence.

During this period, the brain undergoes changes in both its structure and function. For example, the brain gets rid of unnecessary connections (synaptic pruning) and strengthens the remaining connections by adding a fatty substance called myelin (myelination).

The way the brain functions also changes. Areas related to planning, decision-making, and impulse control (executive function) continue to develop. The brain's response to rewards also matures, as does the ability to understand and manage emotions (socio-emotional cognition).

Finally, the balance of chemicals in the brain that play a role in reward processing also changes during adolescence.

Summary of Argument

The law is about how courts should think about teenagers when deciding punishments. Scientists say the brains of teenagers are still growing and changing. This means their brains are not fully developed. Teenagers' brains are still forming connections and getting stronger. They are also learning how to control their actions and think about the future. This is why courts should consider the way a teenager's brain works when deciding on a punishment.