Part 1 can be found here
Tomorrow school is back in session. I was a little down but now I feel absolutely ecstatic. I feel like in my mind I no longer feel the oppression associated with gender roles. I no longer feel that constraining force and I honestly feel like I’ve never been happier in my life. It’s blissful.
And I’m getting off-topic. (I’m human) So, we left off with me giving evidence for brain plasticity being a reality with the discovery of enlarged hippocampi in the brains of London cabdrivers.
Restak reveals one of the “greatest paradoxes of the human brain” (9) shortly after writing about the cabdrivers. This paradox is that as the brain develops into an adult brain from an infant’s brain, it loses neurons and has “fewer components” (9) yet functions even better. Also, as the brain develops into an adult brain, connections/ synapses increase among the surviving neurons.
There are large numbers of neurons in the beginning. Then, we lose cells, but this process isn’t random–we lose those that we don’t use, and preserve those that we do. Therefore our activities specialize our brain–ring a bell? This always occurs. The structure of the brain never ceases to be malleable, plastic, and our activities even when we enter old age continue to shape our brain and its function.
A famous rat experiment conducted by Bill Greenough showed the benefits of new experiences and constant environmental stimulation. There were two groups of rats, one which was hardly stimulated, where the rats were isolated and not offered forms of play and exercise, and another where the exact opposite occurred. In this second group, the rats were offered ways to exercise. They had wheels in their cages, they had ladders and rat company, allowing them to socialize. They were more active than the isolated rats, and when the brains of the two rat groups were compared, the rats with a richer environment were found to have “25 percent more synapses per neuron” (11) than the isolated rats.
“This increase in synapses translated into clever rats that were quicker to wend their way through mazes and learn landmarks faster” (11).
As Restak explained it, the social, sensory and physical stimulation the “privileged” rats received were factors that increased blood supply to the brain and therefore “enhance[d] brain development, lead[ing] to the creation of smarter rats” (11).
*goes to watch rat videos*
You’ll remember me saying that until recently (until the 1980s to be exact) it was thought the different brain regions developed at the same time, but they don’t. This order of mental development in a person is responsible for their relatively immature behavior which becomes more and more mature as they age and their brain further develops.
I’m taking a psychology class in which I had to learn about various brain regions. One of them was the frontal lobes, involved in higher-level thinking, social judgement, planning, decision-making, “ethics, altruism, compassion” (14), etc. According to Restak, they develop much more slowly than other brain regions and that explains why that maturity does not emerge until adolescence, and does not stop developing until adulthood. In some cases, adults’ frontal lobes do not develop properly. This can explain their behavior: it is due to their inability to “plan their lives or control either their emotions or their behavior” (15). When mentioning this, Restak gave the example of many prisoners that he was able to study thanks to his work as a forensic neuropsychiatrist. They suffered from frontal lobes that had not matured properly, and had less control over their behavior as a result.
I’m going to sleep a little late tonight but I need a break from all the math I’ve done all day (studying) and this is it.
Anyway, I’m continuing the summary. Neurons can have many synapses, though those which don’t establish connections die off.
In adolescence, the brain’s frontal lobes have not fully developed, and so there has yet to form a balance between being practical and being idealistic. The prefrontal cortex is also yet immature which is why we see that characteristic teen behavior. Teens can have difficulty making decisions, controlling their impulses, having good judgement, and etc. Adolescents also cope with stress relatively badly. In adults, cortisol levels rise, yet they fall quicker than in adolescents. In adolescents, the amygdala and hippocampus are affected–negatively–by the lingering cortisol. Hippocampus cells can shrink, meaning impaired memory and depression, and so can cells in the amygdala. The amygdala is associated with emotions among other things; as a result teenagers can feel negative emotions such as anxiety. Restak says that “the hippocampus, amygdala, and prefrontal cortex are the three brain areas that undergo major changes during adolescence” (17), and so the effects of stress can be particularly harmful to teens. I feel that in my life I don’t experience much of overwhelming emotions. There are times that I do but I try to return to a balanced state–more quickly now that I’ve learned the importance of stress avoidance.
While we’re on the topic of stress, let me give you information which I deemed helpful when I learned it in my psychology class. The formula for stress reduction is:
perceived control + perceived predictability.
Restak continues to say that these brain areas can be damaged, sometimes irreversibly, by stress hormones, and that behavioral problems in adulthood may ensue as a result.
When the brain reaches adulthood, it does not lose its plasticity; it retains it. The brain, as a result of this plasticity, can become specialized, which should sound familiar. As you may have guessed, the frontal lobes mature, and as a result adults generally enjoy more control over their impulses and emotions. As we age, we find that we lose neurons and synapses, though this is not so bad as losing nuclei. They are cells in cell clusters in the brain stem which send projections to parts of the cortex. Chemical messengers, through these projections, are transmitted to these areas. Here Restak puts it better than I:
“Reduction in the levels of neurotransmitters [aka chemical messengers] leads to many of the infirmities that increasingly afflict us as we get older: memory loss, depression, decrease in overall mental sharpness, inefficient information processing. Fortunately, these infirmities can be improved by drugs that rev up or supplement deficient neurotransmitters.”
I’ll leave part 2 off there.