GREEN PEACE

Speech is the symbolic expression of thoughts in words, that is to say, in patterns of sound formed by the vocal apparatus or characters formed by the hands. It requires the learning of certain convention which differs from one culture and nation to another when the ability to interpret the meaning of conventional sound or visual symbols is lost, though they can be heard or seen, there is receptive dysphasia. When the ability to express ides in sound, written or drawn pattern is absent though there is no paralysis there is expressive dysphasia. Failure of the symbolical aspect of speech must be distinguished from failure to pronounce or articulate correctly which dysphasia. The types of dysphasia may there fore be looked on as special cases of agnostic and paraxial respectively. Complete loss of either aspect of speech is termed aphasia. This classification is satisfactory for routine clinical use through the expert will recognize variants form these major patterns. It should however be stressed that frequently mixed forms of disturbance occur. The neural mechanisms underlying speech are usually situated in the left hemisphere.