Volume 1

Aphasia and kindred disorders of speech / by Henry Head.

  • Head, Henry, 1861-1940.
Date:
1926
Catalogue details

Licence: In copyright

Credit: Aphasia and kindred disorders of speech / by Henry Head. Source: Wellcome Collection.

    560/576 (page 540)
    are still possible. The nature of this disorder of function must be deter¬ mined by direct observation, amplified by the statements of the patient, and described in terms of the affected process. The categories under which these abnormal phenomena are grouped must be dynamic rather than static. When the final response is considered as a form of behaviour there is no necessity to separate mind and body; we can investigate and record on the same principles every morbid reaction from the lowest reflex to the highest form of mental activity. In this way alone is it possible to discover the forms assumed by defects of such high- grade aptitudes as the use of language under the influence of injury or disease. The only link between the facts of anatomical destruction and a disorder of some psychical function lies in a study of morbid behaviour, recorded in categories of the affected process. On the other hand, the same act can be considered from the point of view of mental content, and we are accustomed to think of it as made up of sensations, perceptions, images, concepts, etc. These are convenient abstract terms for real elements of cognitive material. Such elements are discoverable by introspection, but they do not form the categories into which fall naturally the content of disintegrated mental processes. When, for instance, sensation is disturbed owing to injury to the cortex, total sensibility to pain, heat and cold is not affected, but the patient loses the power of appreciating differences of intensity together with spacial and other relations between stimulating objects. In the same way, with disorders of speech we cannot state that visual images as a whole are or are not disturbed; the defects consist of loss of power to employ them in a certain manner and with a distinct purpose. Even symbols can be used in direct relation, provided they do not require some proposi¬ tional formulation. “Sensation,” “perception,” “images” and “concepts” are abstract terms, the result of introspective analysis of the contents of the mind. They are names for cognitive material rather than for the processes of cognition and may be conveniently employed in the formulation of certain facts. For instance, it is useful to be able to state that visual images are affected, when they form part of a certain situation, but not under other conditions. But all such introspective examination is bounded by the limits of consciousness. It is only by probing and analysing morbid phenomena in terms of function that we can arrive at any conception of the inte¬ grative processes and reactions which underlie normal behaviour. Consciousness not only forms one of the factors in behaviour, initiating, regulating and adapting vital reactions, but it enables us to obtain an