carl wernicke
TRANSCRIPT
Carl WernickeBy Charles Lok, Sunwoo Park, & Leslie Chan
Wernicke’s Area
Location and Function
Located at the junction of the partiety, temporal, and occipital lobes in the left hemisphere
Responsible for:
Language Comprehension
Semantic Processing
Language Recognition
Language Interpretation
Discovery
Wernicke (1874) observed that patients with damage to the left temporal lobe had difficulty with speech and understanding sentences
Hypothesized that an area in the left temporal lobe was responsible for speech processing
Method of Research
Observational method (observing brain damaged patients)
Evaluation
Strength Was supported by many studeis that were
conducted later Became the basis of further findings of Wernicke's
Aphasia and Wernicke-Geschwind model
Limitation The results and findings of only patients with brain
damage cannot be applied to the normal people.
Wernicke’s Aphasia
A.K.A – Receptive Aphasia
Results from damage to the Wernicke’s area
Research
Wernicke (1874) found that patients who had sustained damage to the left temporal cortex had difficulty in speaking
Method
Observation
Post-Mortem Studies examining stroke victims
Both methods are limited as they are based on brain damaged patients and thus generalizing the results to the general population may not be valid
Symptoms
A person with Wernicke’s aphasia will most likely: Speak in a regular pace however interchange certain
words for others making their sentences near impossible to comprehend
Have difficulty understanding speech Their speech is unaffected however they do not know that
what they are saying is wrong Reading is near impossible They do not understand what others say
Evaluation
Wernicke’s aphasia and damage to the Wernicke’s area have been frequently correlated
Studies treat Wernicke’s aphasia as a given and expand upon Wernicke's aphasia and normal language processing: A case
study in cognitive neuropsychology. An On-Line Analysis of Syntactic Processing in Broca's and
Wernicke's Aphasia Recovery from wernicke's aphasia: A positron emission
tomographic study
Wernicke-Geschwind Model
Initially, proposed by Carl Wernicke in 1870s
In 1965, Norman Geschwind renewed the theory in 1955
Model of language
Accounts for hearing, speaking, and reading
Process
Hearing
Spoken Word Area 41 Wernicke’s Area Hear and Comprehend Word
Hearing: the hearing process starts off with a spoken word, the sounds of the spoken words are sent through the auditory pathway to Area 41 (primary auditory cortex) also known as the Heschl's gyrus. Subsequently, the sounds of the spoken words continue on to Wernicke's area, where the meaning is educed.
Speaking
Cognition Wernicke’s Area Broca’s area Facial Area of Motor Cortex Cranial Nerves Speak
Speaking: the meaning of words are process in Wernicke's area and then sent to Broca's area, which stores motor programs for speaking words. Moreover, morphemes (the smallest linguistic that has sementic meaning) are assembled here. Therefore, the model suggests that broca's area is in charge of articulating words. Subsequently, the instructions for words are sent to the facial area of motor cortex and then sent to the facial motor neurons in the brain stem, which then sends out orders to facial muscles in order to produce sound.
Reading
Written word Area 17 Area 18, 19 Area 39 (angular gyrus) Wernicke’s area Read
Reading: the visual perception of words are sent to the area 37, angular gyrus (in the parietal lobe), and then to Wernicke's area (for silent reading), if its "reading out loud" then it works together with Broca's area.
Method of Research
Observing damaged patients
Geschwind’s aphasic patients
Limitations
Limited
= Research based on aphasic patients so it does not apply to normal people
Studies that went against it (Penfield and Roberts) in 1959
= effects of the surgical removal of language ares from the W-G model had no correlation to the deficits consistent with the model’s predictions
Strengths
Experiments that supported the model
= Hecaen and Angelergues (1964)
-- they came to the same conclusion with 215 patients suffering brain damage in the left-hemisphere
= Ojemann (1983)
--- electrically stimulated W-G areas
Link to video
This will enhance your understanding of the model
http://www.sagepub.com/garrettbb2study/animations/9.23.htm
Works Cited
http://pages.slc.edu/~ebj/IM_97/Lecture10/L10.html
http://everything2.com/title/Wernicke-Geschwind+model
Glassman
Schacter, Gilbert, and Wegner
Myers