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