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LEARNING DISABILITIES: HISTORICAL PERSPECTIVES - page 2 / 42

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questioned specific aspects of Broca’s observations (e.g., Grodzinsky, in press), and neuroscientists now believe that damage to the right side of the brain can play a role, although limited, in causing speech problems. However, Broca’s claims have largely withstood the test of time.

Carl Wernicke, a Polish-born physician whose family moved to Germany at an early age, was another major figure who explored brain localization during this period. In 1874, he published a book describing 10 case studies of brain-injured patients with language problems. However, the language disorders they possessed were different from those of Broca’s patients as was the particular area of the brain affected (Wernicke, 1874). In contrast to Broca’s subjects, Wernicke’s patients had fluent and unlabored speech, but the sentences spoken were often meaningless. In addition, his cases had difficulties in recognizing and comprehending words. He called this disorder sensory aphasia, which has become known as Wernicke’s aphasia. The particular area of the brain, now referred to as Wernicke’s area, consists of a section of the left temporal lobe.

Research on Reading Disabilities

In 1872, Sir William Broadbent reported on the case of an intelligent adult patient who:

after head symptoms, completely lost the power of reading either printed or written characters, while he could write readily and correctly from dictation or spontaneously. His conversation was good and his vocabulary extensive, but at times he was at a loss for a name, and he was quite unable, when asked, to name the simplest and most familiar object presented to his notice. The loss of power to read was of course a part of this more general loss of power to name. (Broadbent, 1872, p. 26)

Five years later, Adolph Kussmaul (1877) reported on the case of an adult patient with no apparent disabilities other than a severe reading deficit. He asserted that “a complete text-blindness may exist, although the power of sight, the intellect, and the powers of speech are intact.” In emphasizing the specificity of the reading problems, in isolation from other types of potential problems, Kussmaul gave birth to the idea of specific reading disability. Kussmaul labeled the condition word-blindness:

In medical literature we find cases recorded as aphasia which should not properly be designated by this name, since the patients were still able to express their thoughts by speech and writing. They had not lost the power either of speaking or of writing; they were no longer able, however, although the hearing was perfect, to understand the words which they heard, or, although the sight was perfect, to read the written words which they saw. This morbid inability we will style, in order to have the shortest possible names at our disposition, word-deafness and word-blindness(Kussmaul, 1877, p. 770)

A reciprocal academic relationship between two physicians—John Hinshelwood from France and W. Pringle Morgan from England—was the catalyst for extending this work on acquired word-blindness in adults to congenital word-blindness in children. Hinshelwood’s first foray into research on word-blindness was with an adult whom he saw in 1894 and followed until his death in 1903. After his death an autopsy was performed, and Hinshelwood concluded that the section of the brain affected was the left angular gyrus, which is immediately posterior to Wernicke’s area.

Hinshelwood’s paper describing this patient, published in 1895 in Lancet, prompted Morgan to report on what is believed to be the first published case of a child with congenital word-blindness.3 Morgan’s case was a 14-year-old boy who had a history of severe reading problems:

He seems to have no power of preserving and storing up the visual impression produced by words—hence the words, though seen, have no significance for him. His visual memory for words is defective or absent; which is equivalent to saying that he is what Kussmaul has termed “word blind”…

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