The Mind: Insights From Science
M. Bakri Musa
Much of the scientific insights on the human brain emerge from four sources: “wet labs” on laboratory animals; clinical observations on brain-damaged patients; observing babies and children; and human psychology experiments.
Insights on the mind however, are best gleaned through reading Shakespeare and pondering the philosophers.
The current popular specie for “wet labs” is the nematode (worm) Caenorhabditis elegans. It is transparent, easily manipulated genetically, and has only 302 neurons (as compared to billions for humans). It would be far fetched to consider that organism as having a brain compatible to that of humans; nonetheless its far fewer neurons enable scientists to study the basic physiology of nerve cells.
Imprinting experiments with birds, specifically geese, give us insights on such concepts as the “critical” period of learning.
Nothing in nature however is clear-cut. If you cut the nerve to the frog’s eye and then rotate it 180 degrees, and then after the nerves have regenerated, observe the frog catching flies. It could not; its tongue keeps flipping in the opposite direction. The explanation there is that the eye had been “hard wired” to the brain in a certain way and that no amount of “learning” could change the situation. In short, no neuroplasticity (the ability of nerve cells to modify its functions) operating there.
If you were to suture shut one eye of a kitten and weeks later remove the sutures, that eye is functionally blind even though it is still receiving the images. The lack of visual stimulation in that eye disrupts the production of the specific factors needed for the nerve cells to grow longer branches (dendrites) and connect to the brain, illustrating the significant role of the environment in brain development.
Baby monkeys raised in isolation with only a fluffy doll as their “mother” grew up to be severely disturbed, again illustrating the crucial role of early nurturing or mothering.
The second source of insight comes from brain-injured patients. One was the case of Phineas Gage who had a crowbar pierced through his skull. He survived, but his subsequent personality changes were such that he was “no longer Gage.”
Another patient, HM, had a scar surgically removed from an “old” part of his brain (hippocampus) to control burdensome seizures. After the surgery he had severe anterograde memory loss; he could not remember events occurring afterwards. He still had his “old” memories of events before the surgery. That led to the insight of different memories. Certain medications can also cause this distressing side effect, fortunately only transiently.
In the 1960s Sperry studied patients who had their corpus callossum severed to prevent epileptic seizures from spreading from one hemisphere of the brain to the other. The corpus callosum is the thick tissue that sits at the base of and binds the two hemispheres. After surgery these patients would behave like any other normal person, with no impairment of speech, walking, or other activities.
Through studies on these patients Sperry was able to demonstrate the lateralization of brain function, with the right more visual and able to process information in an integrative and intuitive way while the left, more verbal and adept at processing information in a sequential and analytical manner. Popularly expressed, the left-brain is rational and analytical while the right, emotional and creative, a neuro-scientific variation of the Yin and Yang theme. Women tend to use their right brain more than men. The implications of Sperry’s insight go beyond differences in how boys and girls learn; it also explains why men and women differ in their views on social issues.
In 1966 at the University of Texas, Charles Whitman shot and killed 13 people while wounding another 32 before he was shot dead. Whitman left a suicide note, admitting that he had been bothered by irrational thoughts and requesting an autopsy be done as he suspected that there was something wrong inside his brain. They did, and he was right. They found a tumor pressing on his amygdale, the part of the brain controlling emotions, especially fear and aggression.
These and other dramatic if not tragic examples challenge our concept of free will and culpability.
At that time there were no CAT scans or MRIs. Today an enhancement, f MRI (for functional) scan, is an important tool in brain research; it shows which part of the brain is ‘lighted’ or active during dynamic studies.
Another research involves patients with parts of their nervous system damaged from birth and then restored later in life. An example would be congenital cataracts. In developed countries these children would be treated early, with minimal if any eyesight loss. In the Third World these children would remain blind, with all its tragic consequences.
Recently a fortunate few in India were operated on through the surgical intervention of Massachusetts Institute of Technology’s Prakash Project. Contrary to the findings of the earlier experiments with kittens, those treated children were able to see following their cataract surgery. However, they do not “see” immediately, nor is what they see initially the same as what people with normal vision would see.
While we see Holstein cows munching leisurely in the lush meadow under the cloudless blue sky, those children would see blotches of black and white over a green background under a blue patch. They would not see what we see until their brain has learned to interpret those images, a process that could take days or weeks. The images transmitted from their eye to their visual center of the brain (optical cortex) are exactly the same immediately after surgery as well as later, but the brain has not yet learned to see, or interpret those images properly until much later.
The third source of insight comes from observing babies and children. A baby’s brain is neither a blank slate nor an adult one in miniature. A remarkable feature is its steep learning curve, unseen again at any other time. A baby has to learn to recognize its mother and get her attention, process the sights and sounds of the world, as well as learn to crawl, walk and control its sphincters.
This learning predates delivery. The baby in utero learns to recognize the sound of its parent’s voices and the movements of its mother. If the father is absent, then little of this pre-delivery bonding would take place with him.
After birth there is the all-important filial bonding and imprinting. The baby learns to recognize its mother. It can do this within a few days but that recognition is fragile. If the mother were to later wear a scarf for example, the infant would treat that face as that of a stranger. A similar “make strange” response would occur if the mother were to approach the baby from its head, thus presenting to the baby an upside-down image. Only much later does the baby learn to recognize its mother’s face from every angle.
The fourth source of insight comes from the study of normal, healthy human beings. These human psychology experiments contribute much to our understanding of the human brain, and thus the mind. I will devote the next two chapters to reviewing some of the insightful ones.
Excerpted from the author’s book, Liberating The Malay Mind, published by ZI Publications, Petaling Jaya, 2013. The second edition was released recently in January 2016.