Speech- and Language-Handicapped Children

Abstract

In general usage the terms speech and language are used interchangeably. Sematically one has to differentiate between speech and language. Language in its widest sense signifies the elaboration of thoughts and ideas. Language and thought are intimately related and mutually influence each other. Spoken words are arbitrary audible symbols, and propositional, that is, meaningful, speech may be regarded as verbal means of communication, a tool and a manifestation of language.From a phylogenetic point of view, speech is the newest of man's skills. For its normal development one must have a normally functioning brain, adequate hearing, normal peripheral anatomical structures used in speech, and also a stimulating environment.These peripheral structures are not special organs set aside solely for speech. Speech has arrogated to itself structures such as the mouth, lungs, and larynx that biologically perform more vital and quite different functions. The central nervous system acts as an integrator of these organs that are otherwise dissociated in function, and it is only in the brain that certain areas have been developed whose function is predominantly concerned with speech.There are still differences of opinion as to the specificity of function of certain areas of the brain. Some hold that there is pin¬ point specificity and that the function of speech is localized in definitely circum¬ scribed areas-so-called centers ; others doubt this specialization and postulate that speech is the function of the entire cortex.1The term brain center has lately been more clearly defined by Nielsen.2 He points out that center does not mean a delimited cortical zone with independent functional capacity but that it is rather an anatomically delimited zone which is essential to a cer¬ tain function. In this presentation the term center will be used only in the latter sense.The normal activity of the central nerv¬ ous system depends upon the interaction of sensory and motor systems. The sensory, or receptive, component of speech consists of comprehending spoken or written lan¬ guage, i. e., spoken words or written symbols.The motor or expressive component of speech consists in the ability to express words or written symbols. In the develop¬ ment of speech, associations are formed be¬ tween verbal sounds or words and meaning. This is the child's first goal in speech de¬ velopment. The child must first receive the spoken words for a certain period of time in order for the symbols to acquire their characteristic meaning. After hearing and understanding spoken words, he begins to talk. The sequence of events is as follows: receptive speech-inner speech-expressive speech.The auditory word area for the compre¬ hension of spoken language is in the su¬ perior temporal gyrus, Areas 41 and 42-Wernicke's area. There is evidence that the adjoining portion of Area 22 subserves the same function. Area 37 is the language formulation area, where engrams are laid down for the proper arrangement of words into sentences. Area 17 is the primary visual cente...