Wernicke described as a second language center (the first center would the Broca’s) the middle third of the first temporal gyrus left in charge of the comprehension of spoken language. However, Wernicke went further and also proposed as important areas of language that would unite the region Broca’s area with Wernicke (arcuate fasciculus) and where there would be an important flow of information. In short Wernicke not only provides a connectionist model, but introduces the concept of information flow. The postulates of Broca and Wernicke were used to generate numerous diagrams to relate language and brain, as well as to predict aphasic syndromes. The latter was used by Lichtheim (1884) and their classification is even today the basis of the clinical classifications of aphasia. In 1892 Jules Dejerine connectionist continued development through clinical cases and ran a dedicated facility for reading located in the left parietal lobe. However, connectionist theories were being forgotten by political and scientific reasons. The connection is resumed, in the twentieth century with a new perspective, by Norman Geschwind in 1965, introducing changes to the design language brain.
Geschwind proposed that each brain can contain both linguistic and nonlinguistic information. Besides worries about the definition of the neuroanatomical areas that are correlated with language skills. Even found significant asymmetries in the two hemispheres of the brain. In summary, the connectionist models representing language in the brain by means of a set of centers, each responsible for a psycholinguistic function in a specific area of the brain and connected by nerve fibers. Hierarchical Models. John Hughlings Jackson, a neurologist and founder of clinical neurology differs from connectionist models and the location of authority. For Jackson nerve activity is organized in three performance levels: basic or primitive, an intermediate and higher, they are carried out the processes of language (cerebral hemispheres).
In each of the various levels and functions are executed each function is a self-contained, overlap and relate to them. Jackson’s theories are inclusive nature of linguistic and neural functioning, however, showed little anatomical basis. These theories remained in oblivion until 1926. Jackson’s postulates are taken up by Roman Jakobson (1941) who tried to relate one aspect of the model of dissolution of language in aphasia with language development and linguistic universal features. Jakobson sought to develop the concept of hierarchical organization of linguistic units, but like Jackson does not delve into its anatomical correlation. Another hierarchical model is the microgenetic theory of Jason Brown (1980, 1982), which views language as a system consisting of a set of levels that are executed in sequential order. Conducting these processes occur in certain brain areas including cortical and subcortical structures. Hierarchical models mentioned above belong to the so-called holistic theories, which deny the existence of specific cortical centers for speech. Global Models. The global models suggested that acquired language disorders were the product of a single general psychological disturbance. One representative of the models was Pierre Marie (1960) whose ideas established relationships between aphasic syndromes and the vascular anatomy of the brain. The main contribution was to describe neuroanatomical vascular supply to the areas of language. Are you interested in this item?