Learning Disabilities

Children absorb their society's culture, and acquiring language skills seems virtually automatic for most. Yet some people have lifelong difficulties in mastering language-related tasks, difficulties classified by educators under the umbrella of learning disabilities.

Perhaps the most common learning disability is impairment in learning to read, or dyslexia (from the Latin dys, meaning "poor," and lexia, meaning "reading"). Not surprisingly, children with dyslexia have difficulty learning to write as well as to read. In 1895, James Hinshelwood, an eye surgeon, examined some schoolchildren who were having reading problems, but he could find nothing wrong with their vision. Hinshelwood was the first person to suggest that these children were impaired in brain areas associat ed with the use of language.

In more recent times, Norman Geshwind and Albert Galaburda (1985) proposed how such impairment might come about. These researchers were struck by the finding that dyslexia is far more common in boys than in girls. Perhaps, they reasoned, excessive amounts of the hormone testosterone, which produces male physical characteristics early in development, might also produce abnormal development in language areas of the brain. Pursuing this hypothesis, they examined postmortem the brains of a small sample o f people who had experienced dyslexia. They f ound abnormal collections of neurons, or " warts," in the language areas of the left hemisphere. This relation bet ween structural abnormalities in the brain and learning difficulties is further evidence t hat an intact brain is necessary for normal human functioning.

These examples highlight a remarkable feature of the modern human brain: it performs so many tasks in our modern world that were not directly selected for in our early hominid evolution. The brains of early Homo sapiens certainly did not evolve to help program computers or travel to distant planets. And yet the same brains are capable of both these complex tasks and more. Apparently, the things that the human brain did evolve to do contained all the elements necessary for adapting to far more sophisticated skills. Thus, the human brain evolved a capacity allowing it to be highly flexible in accommodating the variety of knowledge and achievements of modern culture.

The acquisition of complex culture was a gradual, step-by-step process, with one achievement leading to another. Among our closest relatives, chimpanzees also have culture in the sense that some groups display tool-using skills that others have not acquired. In her book titled The Chimpanzees of Gombe, primatologist Jane Goodall describes the process by which symbolic concepts, a precursor of language, might have developed in chimpanzees. She uses the concept of "fig" as an example, explaining how a chimp might progress from knowing a fig only as a tangible here-and-now entity to having a special vocal call that represents this concept symbolically. Goodall writes:

We can trace a pathway along which representations of . . . a fig become progressively more distant from the fig itself. The value of a fig to a chimpanzee lies in eating it. It is important that he quickly learn to recognize as fig the fruit above his head in a tree (which he has already learned to know through taste). He also needs to learn that a certain characteristic odor is representative of fig, even though the fig is out of sight. Food calls made by other chimpanzees in the place where he remembers the fig tree to be located may also conjure up a concept of fig.Given the chimpanzees' proven learning ability, there does not seem to be any great cognitive leap from these achievements to understanding that some quite new and different stimulus (a symbol) can also be representative of fig. Although chimpanzee calls are, for the most part, dictated by emotions, cognitive abilities are sometimes required to interpret them. And the interpretations themselves may be precursors of symbolic thought. (Goodall, 1986, pp. 588-589)

Presumably, in our own distant ancestors, the repeated acquisition of concepts, as well as the education of children in those concepts, gradually led to the acquisition of language and other aspects of a complex culture. The study of the human brain, then, is not just the study of the structure of a body organ. It is also the study of how that organ acquires sophisticated cultural skills—that is, of how the human brain fosters behavior in today's world.

Adult Dyslexia

Adult Dyslexia

This is a comprehensive guide covering the basics of dyslexia to a wide range of diagnostic procedures and tips to help you manage with your symptoms. These tips and tricks have been used on people with dyslexia of every varying degree and with great success. People just like yourself that suffer with adult dyslexia now feel more comfortable and relaxed in social and work situations.

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