Memory was assumed to be localized in the fourth ventricle

Antonio Guainerio suggested in the 15th century that word sparsity and naming errors were symptoms of a disturbance of memory, caused by too much phlegm in the fourth ventricle.

Costanzo Varolio and Andreas Vesalius wanted to locate the psychological functions in the soft substance of the brain and to stress the importance of brain volume

Physician Thomas Willis (1664,1672) placed the imagination in the corpus callosum (a bundle of fibers connecting the two brain hemispheres).

François de la Peyronie (1741), a French surgeon, also saw the corpus callosum as the center of the soul. Unitarian theories were criticized by the anatomist Albrecht von Haller as “theories without knowledge.”

Johann Gesner wrote a monograph called “Speech amnesia,” which contained six case studies. He saw speech disorders as a type of memory disorder, caused by inertia in the connections between the different parts of the brain.

At the turn of the 19th century, both theories and knowledge about aphasia existed.

Theories focused on damage to the memory organ or association processes, and the neurological causes were believed to be lesions in the ventricles or the brain substance

The anatomist Franz Joseph Gall was the first person to localize mental faculties in the brain cortex. He explained that the cortex was the highest level of organization of the brain and that the cortex and other areas of gray matter are connected by fibers of white matter. He assumed that the development of the skull depended on the size of the cortex under it.

Bouillaud (1825) decided to prove that lesions in the frontal lobes caused loss of speech. He presented a series of cases where speech disorders were correlated with frontal lobe lesions and a series of cases with lesions of other lobes where there were no speech disorders. Bouillaud found two types of speech disorders connected to brain damage: disorders of “speech movements” and disorders of “word memory”; this was in accordance with the abilities assumed by Gall

Traditionally, neurolinguistics is said to have been born in 1861, when Paul Broca presented his theory, based on a patient’s symptoms and the dissection of his brain. After studying this patient and several others with similar symptoms, Broca presented two important hypotheses in 1865: 1.that it was possible to localize psychological functions in brain convolutions; 2.that linguistic symptoms were caused by lesions in the left hemisphere and that consequently language was lateralized, which was totally unexpected. Broca called the linguistic disorder aphémie (inability to speak)

Meynert claimed that consciousness, intelligence, and memory were cortical but not localized. Inductive thinking was the result of associations between perceptions and deductive thinking was simply an external result of induction. He also compared the cortex of primates and humans

In 1874, neurologist Carl Wernicke presented a theory based on Broca’s findings and on his own dissections of the brains of patients with problems understanding language. Wernicke’s theory was a more elaborate model of the relationship between linguistic functions and brain structures than had ever existed before.Wernicke’s view is strictly associationist and also idealist from the philosophical perspective.

German physician Ludwig Lichtheim(1885) found it necessary to postulate a third language center with an unspecified localization, the “concept center,” in the model of language function which he theoretically constructed on the basis of Wernicke’s model. The model includes auditory input and analysis into auditory word representations in Wernicke’s area.

He studied how stimuli evoke responses and how complex these responses are. Jackson distinguished two levels of language: automatic and propositional. The automatic level consists of stereotyped sentences, certain neologisms (newly created words), and swearing. The propositional level is defined partly by its form (sentences that express a relationship between two objects) and partly by its degree of flexibility (the fact that it can be affected by semantics and by the situation).

Sigmund Freud also attacked Wernicke’s and Lichtheim’s associationism in his monograph “On aphasia” in 1891. He suggested that language could be represented in a “field” in the border area between the temporal, parietal and occipital lobes, where all the properties of an object were connected in a network (smell, taste, look, sound representation, etc.).

Head himself was an adherent of Jackson’s and von Monakow’s theories about the brain as a hierarchic organization of functions as a result of evolution. In his view, brain damage caused “asymbolia” affecting both verbal and nonverbal functions.