Aphasia

A disorder caused by damage to the parts of the brain that control language. It can make it hard to read, or write and to comprehend or produce language.

Developmental Aphasia

• Approximately 1 in 20 children has symptoms of a language disorder. When the cause is unknown, it is called a developmental language disorder.

• Language disorders may occur in children with other developmental problems such as autistic spectrum disorders, hearing loss, and learning disabilities.

• A language disorder may also be caused by damage to the central nervous system, which is called aphasia.

• Language disorders are rarely caused by a lack of intelligence.

Acquired Aphasia

• Result of accident or disease Stroke Tumor Trauma Disease (e.g., Pick’s Disease, AKA

frontotemporal dementia)

• aphasia may occur suddenly or develop over time, depending on the type and location of brain tissue damage.

Paul Broca

In 1861, Broca heard of a patient who had a 21-year progressive loss of speech and paralysis but not a loss of comprehension nor mental function. He was nicknamed "Tan" due to his inability to clearly speak any words other than "tan"

Paul Broca - 1860’s

When Tan died Broca performed an autopsy. He determined that Tan had a lesion in the frontal lobe of the left cerebral hemisphere.

Broca went on to find autopsy evidence from 12 more cases in support of the localization of articulated language.

Broca’s (Expressive) aphasia

Type of aphasia, which involves impairments in speech output.• Halting, non-fluent speech. • Content words are correct but function words

(i.e., articles and adjectives) were impaired. • Grammatical errors• Difficulty in selecting, planning and controlling

speech production.

Ted Talk of Gabby Gifford

Congresswoman Gabrielle ("Gabby") Giffords captured the attention—and deep sympathy—of a nation when she was shot by Jared Lee Loughner in a Safeway parking lot on January 8, 2011, in Tucson. Giffords' injury to her brain's left hemisphere resulted in aphasia.

Carl Wernicke

Wernicke noticed that not all language deficits were the result of damage to Broca's area. He found that damage to the left superior temporal gyrus resulted in deficits in language comprehension. This region is now referred to as Wernicke's area, and the associated syndrome is known as receptive aphasia.

Carl Wernike 1880’s

Example of Wernicke's Aphasia

• Comprehension is impaired• Speech is fluent but has little informational value. They

speak easily or even abundantly, yet may produce unintended syllables of words. They will experience the same difficulties when writing as when speaking.

• Fluent function words, but impaired content words.• Might have

– Random words (Word salad)– Neologisms

Wernicke's Model

Broca’s Area: Speech – Phonemic Movement Programs.

Wernicke's Area – Phonological input Lexicon

Wernicke predicted the existence of Conduction Aphasia in which people can understand speech but make errors in repetition. Due to lesion of the connection between Wernicke's and Broca’s areas.

Arcuate fasciculus

Speech- Phonetic Movement Programs

Motor Systems Auditory Analysis

Phonological Analysis

Speech Input

Lichtheim (1885)

Found cases of patients with conduction aphasia partially confirming Wernicke's Model

But

Also found cases of Transcortical Sensory Aphasia (TSA).TSA is very similar to Wernicke's (Receptive) Aphasia however patients still have intact repetition and exhibit echolalia, or even compulsive repetition of words.

Models of AphasiaWernicke-Lichtheim Model of Aphasia

Speech- Phonetic Movement

Programs D

Motor Systems Auditory Analysis

Phonological Analysis B

Speech Input

Semantic Conceptual Area F

C

EG

A

Boston Aphasia Classifications

Broca’s Aphasia - Speech is laborious and grammar can be incorrect. D

Wernicke's Aphasia: Comprehension is impaired B.

Conduction Aphasia Comprehend and produce speech accurately – difficulty repeating. C

Global Aphasia – neither comprehend nor produce speech. Damage to both Broca’s and Wernicke's areas. B and D

Transcortical Motor Aphasia (TMA)– Similar to Broca’s but can’t repeat . G

Transcortical Sensory Aphasia (TSA) – Similar to Wernicke's but repetition is preserved. EEcholalia.

Isolation Aphasia (Mixed Transcortical Aphasia) – cannot understand or produce speech but can repeat words. E and G

Anomic Aphasia – Problems in naming objects

across modalities. G or E