From infancy to old age our bodies see a multitude of physiological changes. We get taller… and eventually shorter, we grow and lose hair, and our muscle density changes dramatically. As I’m sure you probably imagined, a similar course of changes occur in our brains.
Brain development begins 2 weeks after conception. At this point, the embryo undergoes a process called “neurulation,” a process by which the spinal cord, brain, and peripheral nervous system begins to form (Tierney & Nelson, 2009).
Once we are born, we have a very basic nervous system that rapidly develops over time. An important thing to understand is that new neural circuits are very easily modified by experience. For many of our sensory and perceptual system the first few years of life make up “critical periods” where the use of these circuits is integral to normal development (Zeanah et al., 2011). Animal models provide us with a perfect exemplar for this phenomenon. Experiments done on cats, who had their eyes sewn shut after birth lost the ability to see due to lack of use. When their eyes were reopened (after the end of the critical period) the cats would remain blind (Kiorpes, 2015).
During childhood, connections between neurons are still newer and more easily modifiable. For this reason, children are better able to learn new information rapidly. However, it is important to note that this skill comes at the cost of executive function. This is why children struggle to apply information to new situations, focus their attention, and evaluate consequences. As we age and our existing neural connections become strengthened or pruned, our executive functioning improves while our ability to soak in and incorporate new information decreases (Gopnik et al., 2017).
It is not until around 25 years of age that the frontal lobe (the portion of your brain associated with decision making, critical thinking, and executive function) becomes fully mature (Johnson et al, 2009). Our critical thinking and problem-solving abilities peak during our 30s and then slowly decline for the remainder of our lives (UCSF, 2021).
As we enter older adulthood, our brains slowly atrophy. The fluid filled spaces in and around our brains becomes more pronounced as the nervous tissue recedes. Hormonal changes, free radicals, and reductions in neurotransmitters and growth factors have all been implicated in this process (Peters, 2006).
Although the aging process may seem daunting, the reduction in brain tissue does not necessarily translate to decreased quality of life. Our brains are very good at restructuring to handle new demands. With the right social, psychological, and academic stimulation your brain can age like a fine wine (Peters, 2006).