The Science of Learning, Part 4: Brain Plasticity at Different Ages

The Science of Learning – a 6-Part Series

Part 4: Brain Plasticity at Different Ages

For over a century we’ve known that learning is brain-based. Part 1 of this series introduced the concept of brain plasticity – the brain's ability to change, at any age.

Baby Brains

At birth, each neuron in your cerebral cortex has approximately 2,500 synapses. This number grows rapidly through infanthood. By the time you’re two or three, you have approximately 15,000 synapses per neuron – about twice that of the average adult brain. As people age, however, old neural connections are deleted, through a process called synaptic pruning.

Teen Brains

What is going on inside that unfathomable phenomenon we call a teen brain? Luckily, new scientific theories are emerging that may help solve the mystery. These theories focus on the rate at which modern-day children develop and mature.

The biological and chemical changes of puberty affect the parts of the brain that respond to rewards. Scientists believe that teens “overestimate” rewards – they value them more intensely than adults do. Also, the teen brain (like any other) is seeking control over its environment. However, throughout the past centuries, children have been taking on adult roles (autonomy, responsibility, marriage, offspring) later and later in life. Therefore, as adulthood is delayed, a conflict arises between the control impulse, and the fact that the child has not yet had enough experience to develop the skills necessary for self-control and autonomy. For example, the teen has the drive for sex, power and respect, but their brain lacks the expertise to handle those situations maturely.

So what can we do? Many scientists advocate a graduated system in which teenagers slowly acquire more freedom and more skill. They encourage any activity that sets the child on the path to real responsibilities, experience and control, such as:

• Apprenticeships
• “Take your child to work” events
• Hands-on learning opportunities
• Summer jobs
• Experiential, career-oriented workshops

Fatiguing Brains

Science has also shown that the rate at which brain function increases is directly related to how meaningful or interesting the lesson/task is to the learner.

The brain is a muscle, and like muscle tissue, neural systems fatigue quickly. After 3-5 minutes focused on a single type of activity, neurons become less responsive and need a rest. They can recover quickly, but they need to switch to a different type of activity. In other words, neurons are seeking novelty, and with it, they gain efficiency.

What does this tell us, as educators? Facts must be linked to “real-life” context. A lecture of unrelenting factual material will be tuned out after a few minutes. Re-engage the students’ brains by providing anecdotes that add context. The anecdotes will be most effective when they affect the emotional parts of the students’ brains – humor, empathy, excitement – or apply directly to their lives.

Aging Brains

If scientists still believe that “Practice makes perfect,” do they also believe “You can’t teach an old dog new tricks?” On the contrary. The science of brain plasticity has proven that cognitive function can improve at any age, and cognitive decline can be reversed.

The real problem may be that we’re no longer forced to learn new things. By the time we’re in our 30’s or 40’s we’re generally settled into a career and are reusing the abilities we learned earlier. We’ve mastered many skills, and can now do them “in our sleep.” In other words, we’re no longer applying our brains. Newfangled tools and gadgets compound the problem by making life easier for us, and “saving” us from having to apply ourselves.

A wide range of books and online tools are now available, as a counter measure, to help improve “brain fitness.” The underlying message in these tools: engage your brain, and continue to seek new knowledge.

Come back next week, when we’ll present Part 5 in this series, discussing the differences between male and female brains. (Are we truly from two different planets?)