Is the brain getting old? And if so, at what rate? When does it reach its peak? And can a 65 year old keep his brain young?

While measurements such as height and weight give a relatively clear picture of a person’s physical development, in the case of brain development, much less can be measured and thus learned.

To better understand its function, an international team of researchers collected brain scan data from a number of separate studies with a total sample of 101,457 brains at each age stage. The CT scan of the youngest brain belonged to a 16-week-old fetus, while the oldest brain came from a 100-year-old woman.

From this vast range of data, some startling facts emerged.

• The thickness of the cerebral cortex, filled with folds of the outer layer of the brain responsible for processes such as speech, perception and consciousness, reaches its peak at the age of two years.
• The volume of gray matter, which is made up of nerve cell bodies, peaks in childhood, around the age of seven.
• White matter, made up of connections between neurons that allow areas of the brain to communicate quickly, peaks around age 30 and begins to decline later in adult life.
• The size of the ventricles, the fluid-filled cavities of the brain, increases rapidly in later life, with larger size associated with some neurodegenerative diseases.

“The absolute differences in the size of these traits are somewhat minor. They are useful in terms of comparing benchmarks for each age given the power of these processes,” explains Jacob Zeitlitz, co-leader of the study and research fellow at the University of Pennsylvania’s Brain Life Institute.

As we age, brain development becomes more and more variable. Even different parts of the brain, such as areas responsible for vision or speech, reach their milestones at different ages, notes Sahar Ahmad, a researcher at the University of North Carolina School of Medicine who specializes in neuroimaging of brain development.

newborn age

The brain of babies, like a sponge, absorbs all kinds of information from the outside world.

For example, in the first year of life, infants can learn any language, although this ability is quickly limited by the sounds or signs they hear or see.

In addition, important cellular and genetic processes take place. While most neurons are created at birth, other types of brain cells, such as glia, grow and mature rapidly during the first few years of life. Glial cells continue to mature for many decades.

2-10 years

From around 18 months of age, the brain switches to learning, which includes both strengthening important connections and cutting back on unused ones.

Babies lose about half of their newly formed brain synapses in a process called “synaptic pruning,” which allows them to control more basic and complex functions. At the same time, myelination takes place, a process in which parts of neurons are isolated by a fatty protein, myelin, which increases rapidly in childhood and beyond.

Adolescence, 10-19 years old

Between the ages of 10 and 19, there are dynamic changes in the brain networks involved in learning how to process emotions and motivation as teens begin to move away from the safety of the family home.

“In adolescence, you must learn to stand up for yourself, because you do not have the same protection from your parents as you did when you were young. Learning the boundaries of social norms is exactly what defines adolescence, preparing a person to become a functioning adult,” explains M. T. Casey, professor of neuroscience at Barnard College.

20-39

It is often believed that between 25 and 29 years of age, brain development has reached its peak. This myth is partly based on the observation that white matter, a measure of “speed” of information processing, peaks at this age.

However, scientists say that the brain does not stop developing.

As the brain ages in 30-40 years synaptic plasticityIt is believed that the ability of the nervous system to change its structure and function throughout life in response to life changes is redefined rather than diminished.

“The system is just it starts to work differently. It’s moving towards something maybe a little more strategic and long-term than “I have to remember exactly what it is and be fast and smart like I was in my 20s,” explains Mark Harnett, assistant professor of brain and in Cognitive Science at MIT, which studies how neurons interact in circuits and networks that drive complex behavior.

40 and above

When we lose our keys or forget our name, we may worry that our brains aren’t working the way they used to. But a new study debunks the notion that plasticity, the brain’s ability to respond to change, is declining in the brains of adults and older adults.

Harnett’s research recently showed the presence of “silent synapses”, that is, connections that remain inactive until they are activated to form new memories in adult mice. These synapses have been associated with early development, but Harnett and colleagues confirm their widespread presence in adult brains at different ages.

These findings show how the brain can change drastically in adulthoodchanges the view of scientists on brain aging.

“Everyone believes that with age, plasticity disappears, and neurons just die. Here we find something really powerful. The adult cortex has all these silent synapses and all this extra plasticity potential. It’s incredible, we didn’t know this existed, it’s exciting,” says Harnett.

From the age of 40, life shifts into the more demanding roles of adulthood—career, family, and helping the next generation. Experiences such as exposure to stress and increased levels of toxins can dramatically affect the development and aging of the brain.

A 50-year-old who has an active social life and regularly plays sports, travels, or volunteers may have a “younger” brain than a more isolated 50-year-old who rarely participates in social processes.

65 onwards

As we age, the brain shrinks in size and its functions may begin to decline. However, many older people have access to more wisdom based on life experience.

Source: Washington Post.