Psycholinguistics

1. Psycholinguistics

2. Psycholinguistics and Neurolinguistics • Psycholinguistics: study of language acquisition, storage, comprehension, and production • Neurolinguistics: study of the neural and electrochemical bases of language development and use

3. Brain Architecture • Right and left hemispheres • Hemispheres are connected by the corpus callosum • Brain is covered by a membrane called the cortex • Bumps on the brain are called gyri, depressions are fissures

4. Cortex Areas • Auditory cortex: receives and identifies auditory signals; Converts them into forms understandable by other areas of the brain • Visual cortex: receives and interprets visual stimuli; Storage site for pictoral images • Motor cortex: sends signals to muscles to make them move

6. Language Centers of the Brain • Broca’s area • Located at the base of the motor cortex • Responsible for organising articulatory patterns of language • Directs the motor cortex when talk is required • Controls use of inflectional and function morphemes

7. Language Centers of the Brain • Wernicke’s area: • Located near the back of the auditory cortex • Responsible for the comprehension of words • Selects words when producing language

8. Language Centers of the Brain • Arcuate Fasciculus • Nerve fibers connecting Broca’s and Wernicke’s areas • Allow the two areas to share information • Required for accessing of the ‘mental lexicon’

9. Language Centers of the Brain • Angular Gyrus • Located between Wernicke’s area and the visual cortex • Converts visual stimuli into auditory stimuli and vice versa • Allows matching of spoken and written forms to the objects they describe • Crucial for reading and writing

10. Language Disorders Aphasia: “…An inability to perceive, process, or produce language because of physical damage to the brain,” (p.62).

11. Language Disorders • Broca’s aphasia • Individuals suffer from an inability to plan the motor sequences for spoken or signed language • Comprehension is not affected; This is an expressive disorder • Speech is halting, patients have a hard time forming words • Sentences may lack inflection and/or function morphemes (e.G. To, the, etc.)

12. Language Disorders • Wernicke’s aphasia • Individuals suffer from the inability to understand the speech of others • This is a receptive disorder • Patients may produce semantically incoherent speech, e.G. Use of circumlocutions • Syntactic word order may be altered

13. Language Disorders • Conduction aphasia • Results from damage to the arcuate fasciculus • Individuals may sound like sufferers of Wernicke’s aphasia (fluent but meaningless speech) • Sufferers will be able to understand speech, but not to repeat it • Results from the inability to transmit information from Broca’s to Wernicke’s areas and vice versa

14. Language Disorders • Alexia: • Caused by damage to the angular gyrus • The inability to read and comprehend written words • Caused by the inability of the angular gyrus to match the visual word to the phonetic form in Wernicke’s area • Agraphia: • The inability to write words • Caused by the inability of the angular gyrus to relate the phonetic form of a word to the written form (Not related to dyslexia, which is caused by a structural portion difference of the temporal lobe, and which may be overcome with proper training)