It’s so cool that a piece of the brain about the size of a grain of rice, can do so much…

paraphrase of a student’s reaction after viewing a video about the brain.

The brain is a fascinating organ! I think so, and this week, my students were reminded of how amazing the single  most important organ really is. Most of my classes on educational psychology and human development begin with a discussion of the brain, since the brain is the foundation of all learning. So today, I thought that it was appropriate to let the brain be the center of my next blog, elevating it to its rightful place, at the pedestal of human physiology and functioning (well, it is at the apex of our body, isn’t it?).

Let’s begin though with learning.

What is learning?

Many educational psychologists conceptualize learning as a relatively permanent change in behavior or behavior potential brought about as a result of practice or experience. Therefore, if there is no relative permanence to the behavior we would argue that learning has not occurred. Learning  is not necessarily directly observable either, and can simply be a change in behavior potential. An example that I use sometimes – because there is at least one student guilty of it right at that moment – is the learning of life’s lessons as a result of the negative consequence that occurred after engagement in the activity which the learner attributes to be directly associated with the behavior: Rock that chair back too far, and you might fall. If you do fall, then you might think twice about doing it again, unless you enjoy falling, and some of us might. At a more extreme end the following sequence of events: drink, drive, get into an accident, might teach one a valuable lesson about drinking and driving.

There are many theories about learning that have been postulated over the years (behaviorist, constructivist, information processing etc.), and I will address those in individual blogs. Learning begins even before we are born, and continues throughout life. However, at the root of all learning is the actual physical changes which occur within the brain, at the neural level, and that’s what some my students found kinda cool.

The Human Brain: A Condensed Version

The human brain is composed of about 100 billion neurons! If you are like me, you can’t even begin to wrap your mind around that. Neurons are specialized cells which are capable of transmitting electrical and chemical impulses at about 270 mph. Hey that’s faster than a lamborghini!  These are densely packed together, and at full growth, weighs about three pounds. For comparison, all human skin (on average of-course) weighs about 20 pounds,

the liver about 3.2, and the heart about 0.6 pounds. During early pregnancy, neurons develop at the rate of 250,000 neurons per minute. At birth we have most of the neurons that we will ever have, and by 2, our brains is about 80 percent of its adult size.  During the first three years of life, the brain has about twice as many synapses (junction between neurons) as it will need as an adult. So, initially we have an overproduction of synapses through the process of synaptogenesis, and during important critical periods of development: (1) from birth to about three and (2) right before puberty. The first one, scientists knew about however, the second was surprising.

Starting from about the age of three, the process of pruning (much like a tree) begins; weak connections are cut back and others flourish. Giedd and his colleagues found that the prefrontal cortex,  the area of the brain right behind the forehead, starts growing again just before puberty (about the age of 11 for girls, and 12 for boys), then a pruning back in adolescence.   This is particularly important because it is responsible for impulse control, organization  and reasoning skills, and it also regulates short-term and long-term decision making. As the prefrontal cortex matures we become better at these, we make better judgments, and develop more self-control. This explains some of the behaviors that are associated with the terrible teens!

It’s really kind of unreasonable to expect adolescents to have the organizational and reasoning skills of an adult, when their brains are simply not ready!

Now, there’s no need to be alarmed. Although one may think that having a lot of connections is a good thing, the quality of those connections is more important.  As we interact with our environment, learn and engage in varying tasks, connections are strengthened. The connections that are not utilized weaken and eventual die (pruning). Hence, what a teen does or does not do during this very important period of their development, can affect them for the rest of their lives because of the “use it or lose it principle.” Turns out it does matter whether your teen elects to watch t.v., play video games, read a book,  or learn a new skill!

What an adolescent spends time doing can potentially impact them for the rest of their lives, since activity determines the hard wiring of the brain!

For the rest of us, our saving grace,  is the brain’s  amazing quality known as plasticity which drives our ability to learn throughout our lifespan. Although, it is strongest during childhood and explains kids’ remarkable ability to learn, according to the society for neuroscience, it remains “a fundamental and significant lifelong property of the brain.”

Well, now you know.

… Sitting on your shoulders is the most complicated object in the known universe.
Read more at: http://www.brainyquote.com/quotes/quotes/m/michiokaku615181.html?src=t_brain

 

Brain Facts

1. The brain is the fattest organ in the body; comprised of about 60% fat!
2. While awake, a human brain can generate enough energy to power a light bulb (between 10-23 watts). My students really love this one!
3. The brain has no pain receptors; that’s why brain surgery is possible while the patient is awake.
4. Meditation changes  brain structure positively. So consider taking up meditation.
5. There are 100,000 miles of blood vessels in the brain.
6. Humans continue to make new neurons throughout life in response to mental activity.
7. You can’t tickle yourself because your brain distinguishes between unexpected external touch and your own expected touch.
8. Einstein’s brain was similar in size to other humans except in the region that is responsible for math and spatial perception which was 15% wider than average.
9. Ninety minutes of sweating can temporarily shrink the brain as much as one year of aging.
10. Our brain needs cholesterol. About twenty-five percent of the body’s cholesterol is found in the brain. Brain cells die without adequate cholesterol.
11. The male brain is about 10 percent larger than the female brain across all the stages of development. There’s no known advantage to that, so you can relax!
12. Chronic exposure to stress overloads the brain with powerful hormones that are intended for short-term functions in emergency situations. Long-term exposure has a cumulative effect that kills brain cells.ⁱ

References

Bjorkhem, I., & Meaney, S. (2004). Brain cholesterol: long secret life behind a barrier. Arterioscler Thromb Vasc Biol 24 806–815,

RandomHistory.com (n.d.). 69 Interesting Facts about … The Human Brain. Retrieved from http://facts.randomhistory.com/human-brain-facts.html