Posts Tagged ‘right hemisphere’

The Effects of Brain Damage

July 21, 2019

This post is based on a book by Stefan Van Der Stigchel titled “How Attention Works: Finding Your Way in a World Full of Distraction.” Visual neglect is a condition in which patients experience problems moving attention to the left or the right side of the visual world. Neglect usually results from damage to the right hemisphere of the brain. The attention regions in that part of the brain are responsible for moving attention to the left visual field. This condition has different levels of severity, and patients with the most severe form are completely unaware of what goes on in the neglected half of their world. When someone with this condition eats they eat only the food on the right-hand side of the plate. When they finish eating they believe that they have eaten everything because they have no access to the information on the other side of the plate. Only when his plate is turned around does the other half of his meal appear in the “intact” part of his visa world and does he realize that he hasn’’t finished his food after all. Neglect patients are actually able to move their attention, but only after receiving clear instructions and only for a short period of time.

Dr. Van Der Stigchel writes, “Around 25% of all patients with brain damage suffer from some form of neglect. Fortunately, it is usually a short-term problem. This is because there are all kinds of processes in the brain that are disrupted in the acute phase, but that are eventually able to return to normal. After a stroke, for example, excess blood has to be drained off from the brain. When that is done, many brain brain functions return to normal and the problem of neglect just vanishes. Even within only a few days of suffering brain damage, a patient may show no more signs of neglect. However, for some patients neglect remains a chronic condition, meaning that the problems they have with moving their attention are permanent.”

Cortical blindness is different from visual neglect and much more serious. Unlike neglect, cortical blindness is not an attentional deficit. There is no visual information in the blind field to which patients can move their attention. People suffering from cortical blindness cannot see any colors, shapes, or other visual building blocks in the affected field.

The Myers-Briggs Type Indicator (MBTI)

March 23, 2019

This is the seventh post in series of post based on a book by Stephen Kosslyn and G. Wayne Miller titled “Top Brain, Bottom Brain.” The subtitle is “Harnessing the Power of the Four Cognitive Modes.” The MBTI is the bane of most psychologists. Once people know that you are a psychologist, it is not unlikely that they will expound on the marvels of the MBTI. Moreover, it is used in some Intelligence Agencies. According to one estimate, about 2.5 million people a year take the test. So HM never resists the opportunity to set people straight on the MBTI.

The MBTI is scored on four dichotomous dimensions:

Extraversion vs. Introversion, which focuses on what sort of activities energize a person: Extraverts draw energy from interacting with others and are dampened down when they spend a lot of time alone; the opposite is true for introverts.

Sensing versus Intuition, which focuses on what a person prefers to pay attention to: Sensing types are very concrete, preferring factual material that is predigested and handed to them instead of material that requires them to abstract and organize meaning to distill underlying principles; the opposite is true for intuitive types.

Thinking versus Feeling, which focuses on decision-making preferences: Thinking types are logical, systematic and relatively detached when making decisions; feeling types are more inclined to rely on emotional considerations and to strive for overall “harmony.”

Judging versus Perception, which focuses on preferences for how to act in the world at large: Judging types like to plan and organize; perceiving types prefer to be open to new possibilities as they arise.

On the face of it these dimensions seem reasonable, and it is clear why this test has intuitive appeal.

But

The test was not developed by psychologists, statisticians, or any type of professional. Katherine Cook Briggs and her daughter Isabel Myer Briggs began to develop this test during WW2 as a tool to help women discover which wartime jobs would be most comfortable and appropriate for them. The test MBTI was the tool. Here are the problems:

It is not based on science; instead, it largely grew out of Jung’s theory of psychoanalysis, which he formulated on the basis of intuition and clinical observations.

Some of the assumptions that underlie the test appear to be contradicted by scientific findings. For example, the MBTI is scored as if “intuition” is distinct from “feeling”—but much evidence now indicates that emotion often underlies hunches.

When items are analyzed so that the underlying factors can be discovered, the results do not correspond to the four dimensions posited by the theory.

When scores are analyzed, they do not cluster around the middle of the dimensions.

in spite of the fact that the test developers stressed that their test is designed to assess preference and not abilities, researchers have examined whether scores predict performance—and they do not consistently do so. Moreover, when they do predict performance, this may be a consequence of the correlation between the MBTI scores and other measures.

Numerous researchers have found that the test has poor reliability. Test takers often get a different score when they take the test a second time.

In addition to the MBTI the authors of “Top Brain, Bottom Brain” also debunk a view of personality that focuses on the anatomical distinctions between the left and right halves of the brain. Although there are differences, under normal circumstance the two halves do interact, and way too much has be made of this theory.