In today’s experiment, we are going to isolate chemical A, purify chemical B, quantify chemical C, and characterize chemical D. Then we will somehow combine A, B, C, and D in a Dr. Frankensteinesque attempt to synthesize chemical E. Chemicals A, B, C, and D are probably interchangeable, and there is no particular sequence in which the reactions need to take place. No lab manuals, and no rules. Experiment ad lib! We should expect a small explosion which will consist of a bang, a crack, and a flash of light. Scary, perhaps, but it is not at all dangerous…. Or is it?
Just as a laboratory experiment needs organized and clearly written experimental procedures, information processing by the brain requires logical sequence and an understanding of the information presented to the brain. If the information is not understood, the logical brain will not be able to associate the information with prior knowledge and memory to make it meaningful. Conversely, without logic and critical thinking, intelligible information will not be given context, and will not elicit meaningful response or be useful for decision-making. Clearly, many pieces of the puzzle need to be in place before information can be effectively processed. Fortunately, we are equipped with two built-in computers—namely, the two halves of the brain—to process information.
As early as the 4th century BC, dissimilarities between the two sides of the brain have been documented . Diocles of Carystus, a celebrated Greek physician from that period, wrote:
“There are two brains in the head, one which gives understanding, and another which provides sense-perception. That is to say, the one which is lying on the right side is the one that perceives: with the left one, however we understand.” (as cited by Bruce Morton )
Differences between the two sides (or hemispheres) of the brain, known as “hemispheric dominance” or “lateralization” has long been a fascinating area of research [2,3]. Language laterality was one measurable feature, first observed in individuals who had left-sided brain lesions back in 1836 . Because these individuals were not able to speak, the left hemisphere was thought to be the language-dominant side. By the 1960s and early 1970s, many researchers still believed that the left hemisphere was the language or verbal specialist and the right side the nonverbal specialist . These distinctions sparked much publicity and led to a substantial body of research, especially in the area of information processing.
Language is but one of many types of information processed by the brain. Another area of particular research interest concerns visual-spatial processing which was thought to be dominant in the right hemisphere. Over time, the left hemisphere gained reputation as the linguistics centre, whereas the right side the processor of visual images and spatial relationships.
These distinctive thinking and learning styles led to the development of educational programs geared towards stimulating one specific side of the brain. Many have even taken the “left brain, right brain” concept and applied it to career selection. However, this practice is not entirely without basis. Interesting observations have indeed been made in small samples of individuals from different walks of life. In one study, 86% of microbiologists and 83% of biochemists were found to be left brain-oriented . This came as no surprise because the left side is thought to contribute to critical and analytical thinking skills essential for these professions. On the other hand, 71% of astronomers and 67% of architects were deemed right brain-oriented . The right hemisphere is, of course, considered the more holistic or abstract faculty important for these professions. As such, hemispheric dominance appeared to play a role in determining our individual talents and inclinations towards certain career choices.
To understand the inner workings of the human brain, we must first examine the structure of this very complex organ. Within the confines of the rigid skull, the two mushy hemispheres are not only close neighbours of each other, but are in fact joined in the middle by a band of nerve fibres called the corpus callosum. This connection allows transfer of information between the two sides of the brain. Just how much communication occurs, such that the two sides may share their specialties, was difficult to elucidate until “split-brain” experiments were performed. In the 1940s, several researchers suggested that epileptic seizure signals could travel across the corpus callosum and spread from one hemisphere to the other . It was thought that cutting the corpus callosum could be a treatment option. Individuals who received this operation were referred to as split-brain patients.
After 6 to 12 months of post-surgical recovery time, most split-brain patients were able to carry out ordinary daily activities . Because it was assumed that the two hemispheres no longer communicated with each other, experiments in these patients sometimes revealed functional dissimilarities between the two hemispheres. These dissimilarities lent support to the notion that the left hemisphere processes language and thinks in logical categories, while the right side handles mental imagery and spatial awareness . However, many factors need to be considered before these observations could be generalized to normal individuals. First, the test subjects had severe and longstanding epilepsy such that their neurological condition might have caused some disturbance in the function of their brains, even before surgery . Secondly, the surgical procedure could produce functional disturbances that might affect subsequent performance [2,8]. Also, laboratory conditions in which the patients were tested were highly unnatural and did not represent real-life situations .
Dominance of the left hemisphere in language processing is largely supported by observations of language difficulties experienced by patients who suffered left-sided injury or stroke . But such deficits were observed only in some patients. The most likely explanation is that language is largely but not exclusively handled by the left side . Using brain scanning technology, recent studies suggest that the left hemisphere handles words, word sequences and grammar, while the right side processes the intonation and emphasis aspects of language as well as the context and meaning of the words or sentences .
Similarly, functions that have long been attributed to the right hemisphere are not exclusively so. There is, in fact, an area in the right brain that “reads” people’s facial expressions . However, reading facial expressions is only one of many functions that require visual perception and imagery processing. In one test, for example, patients who suffered strokes were asked to reassemble an object that had been taken apart . Patients who had right-sided brain damage were only about twice as likely to have impaired visual-spatial performance compared to those with left-sided lesions . Therefore, visual-spatial thinking is not exclusively right-sided. While both sides of the brain “sees” an object, the left hemisphere identifies the structural features of that object, and the right hemisphere determines its relative location and puts isolated elements together [11,12].
It has now become quite clear that the two hemispheres complement each other as far as language and visual-spatial information processing are concerned. Differences do exist crediting the left side with slightly greater linguistic ability and the right side efficiency in visual-spatial processing. But the differences are likely much smaller than they were originally described. Some researchers now believe that a truly meaningful difference exists not in the information that are presented to both sides of the brain but in the processing style of the two hemispheres. A widely accepted view is that the left side specializes in analytical processing, the right in holistic or abstract processing; but this is difficult to substantiate in the laboratory . The main problem is that researchers often disagree on whether a task designed to test processing style requires analytical or holistic processing . Indeed, there is hardly any task in our daily living that requires only one type of processing. The complexity of the brain is such that both hemispheres likely participate in every aspect to optimize survival and intellectual development.
Recognizing that the two sides of the brain complements and collaborates with each other is a step towards the understanding of the brain’s full potential. Clearly, intellectual development requires active participation of a variety of brain functions, and teaching-learning approaches should encourage “whole-brain participation.” It is becoming more and more important for scientists to have strong communication skills. Today’s scientists spend a great deal of time writing grant applications, giving seminars, meeting with collaborators, and teaching students. These roles require that scientists be very effective communicators. In every instance, the message communicated by the scientist involves some degree of teaching. The scientist who is able to integrate such skills as language, logic, critical thinking, visual-spatial awareness, creativity, and memory in her teaching is one whom I will refer to as a “whole-brain scientist.”
It has been said through the ages, “a picture is worth a thousand words.” An illustration or a three-dimensional model of double-stranded DNA likely communicates its structure more effectively than a thousand-word essay. Therefore, the whole-brain scientist is one who adds diagrams, schematics, animation, and three-dimensional models to her verbal or written teaching material to help learners generate mental images. Visual-spatial thinking is now widely promoted as an effective teaching tool [11,14]. A recent paper in the British Medical Journal entitled “Understanding sensitivity and specificity with the right side of the brain” illustrated how statistical concepts that were initially difficult for students to grasp could be effectively communicated using diagrams .
Whole-brain learning is also thought to have self-propagating properties; that is, the more we use both sides of the brain together, the more the use of each side benefits the other . For example, it was observed that the study of music helped the study of mathematics, and vice versa . As such, whole-brain development may have important implications for scientists whose jobs are traditionally more left brain-oriented. In fact, visual-spatial thinking has made an impact in the careers of some famous scientists. It was reported that Albert Einstein used “highly visual thought experiments” to explore ideas, and Friedrich August Kekulé came up with the ring structure of benzene while daydreaming !
I hope that reading this article has, in some way, involved your whole brain. While you read, your left hemisphere processed words and word sequences, and your right hemisphere supplied context and meaning . It is important that scientists recognize the potential of the two hemispheres to complement each other and provide opportunities for them to exercise collaboration. Although this article is not accompanied by photographs or schematics, the explosion mentioned in the opening paragraph, with such descriptors as “a bang, a crack, and a flash of light” might have invoked in your mind a picture of the disaster that would ensue if a no-brain scientist were in charge.
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