- Brain maturation study was initiated by the legal system that needed to ascertain if an individual can be held responsible for a crime.
- The brain matures at different rates for people and some regions of the brain maturing at faster rate even within the same individual, says Harvard psychologist.
- Studies found that some 8-year-old brains were more mature than some 25-year-old brains
Human brain maturation is a complex and yet dynamic process that is imaged using MRI over a period of time. The legal age to vote is 18, and the law across the world defines that brain matures between the age of 10 to 20 years. However, neuroscientists are still divided about this generalization on the maturation process of the brain. According to a group of scientists, different parts of the brain mature at different ages.
Harvard University Psychologist Leah Somerville used recent advancements in technology to try and define when the brain matures and the opinion is published in the Journal Neuron. The need to define when the maturation of the brain occurs began as a scientific pursuit but more recently the U.S legal system has asked for further information on the the age of brain maturation to understand when an individual may be treated as an adult. This question is of specific importance during criminal proceedings, though the Harvard University scientist started the study with an aim to provide an answer, the complexity of the definition made it seem futile. This was because, different regions of the brain matured at different rates, making it difficult to pinpoint a specific age of brain maturation.
The Harvard Psychologists identified the following 5 signs of aging.
- There were structural changes that were identified between an adult brain and an adolescent brain: The amount of grey matter was reduced while the amount of white matter was increased.
- The maturation of the brain is not associated with specific time points: There are individual variations. Different parts of the brain were found to mature at a different age, with some parts not maturing even after the individual reached 30 years of age.
- The plasticity of the brain is dynamic: The ability of the brain to interact with the environment, grow neurons and to add connections is dynamic. The study found that the ability of the brain to create new interactions is not associated with age, as in the study there were some 8-year-old brains were found to be more mature than some 25-year-old brains.
Discerning whether a brain is mature or immature is not an easy task as there are many factors that play a role. The only strong point is that the adolescent brain is very different from an adult brain, however, there is no overnight transformation that occurs which result in a mature adult brain. The legal age, fixed at 18 years, may not be the age at which the brain matures for everyone, and even if it was for some, it would have taken a considerable period of transformation.
The scientists hope to provide a definition for brain maturation that can be used by the legal system to create a reliable system of determination. Identifying when an individual is responsible for his actions will afford better convictions.
"We want to help policymakers understand that the idea of maturity itself just can't be static. The brain is constantly changing, but in ways that are more subtle than the major developmental events that we think about in childhood and adolescence," added Dr. Somerville.
Brain studies has a lot of relevance not only to identify age of maturation but also to identify the cause of many disorders associated with the brain like Alzheimer's or Attention Deficit Hyperactivity Disorder (ADHD). Though ADHD is not a debilitating condition, it could affect the development of the child. ADHD is characterized by an increase in grey matter as well as reduction in brain size in certain portions of the brain.
Studies conducted on children with schizophrenia showed that there was an increased reduction in white matter, 3-4% per year when compared to 1-2% per year for healthy controls. The studies also found a reduction in the parietal region of the brain which is associated with language and thinking, explaining the symptoms associated with the condition.
The study conducted by The Harvard University psychologist is the first step towards understanding the complexities of brain maturation. Though the study has been aimed at assigning criminal proceedings against individuals who could be held responsible for a crime, further studies could aid in identifying the causes for diseases or to improve brain acumen.
As our understanding of brain maturation process improves, there could be an individual evaluation to qualify as an adult in a society and one may need to go through a procedure before they enjoy certain adult privileges in life.
- Mapping brain maturation - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3113697/)