Ch 8: Language

How does handedness relate to lateralization of function?

How does the lesion method test for lateralization of function?

Physicians characterized patterns of language impairment that accompany specific brain lesions

How does the Wada Test test for lateralization of function?

Single brain hemisphere is anesthetized and then the patient is asked to name a series of items

How does task-based fMRI test for lateralization of function?

Symptoms of Broca’s Aphasia

• CANNOT produce speech

• Can comprehend speech

• Cannot repeat words/phrases

Area of injury for Broca’s Aphasia

Broca’s Area

Symptoms of Wernicke’s Aphasia

• CANNOT comprehend speech

• Can produce speech

• Cannot repeat words/phrases

Area of injury for Wernicke’s Area

Wernicke’s Area

Symptoms of conduction aphasia

• Can comprehend speech

• Can produce speech

• CANNOT repeat words/phrases

Area of injury for conduction aphasia

• Arcuate fasciculus

• supramarginal gyrus

• planum temporale

Symptoms of global aphasia

• Cannot produce speech

• Cannot comprehend speech

• Cannot repeat words/phrases

Area of injury for global aphasia

Extensive injury to majority of language areas

Symptoms of transcortical sensory aphasia

CAN produce speech

Cannot comprehend speech

CAN repeat words/phrases

Area of injury for transcortical sensory aphasia

• Posterior to Broca’s Area

• near Wernicke’s Area

Symptoms of transcortical motor aphasia (TMA)

Cannot produce speech

CAN comprehend spoken language

CAN repeat words/phrases

Area of injury for transcortical motor aphasia

• Just in front of or near Broca’s Area

Symptoms of mixed transcortical aphasia (MTcA)

Cannot produce speech

Cannot comprehend spoken language

CAN repeat words/phrases

Area of injury for mixed transcortical aphasia

Lesions AROUND Broca’s Area and Wernicke’s Area

• but NOT to them

Symptoms of Anomic Aphasia

• Impaired object naming and word recognition

Area of injury for Anomic Aphasia

typically a left hemisphere lesion

Symptoms of Semantic Primary Progressive Aphasia (svPPA)

Difficulty in word comprehension and naming

Symptoms of Nonfluent/agrammatic Primary Progressive Aphasia (nfvPPA)

• Reduced speech output

• Problems with pronouncing words

• Slower speech

• Problems with sentence structure

Symptoms of Logogenic Primary Progressive Aphasia (lvPPA)

Word-finding impairment

Primary Progressive Aphasia (PPA)

subtype of frontotemporal dementia (FTD)

• Neurodegenerative disorder with progressive decline in language functions

What evidence is there from double dissociation studies for specific brain areas for specific language functions?

How has research with fMRI and other methods indicated overlapping and integrated language processing systems?

How has EEG been used to study language functions in the brain?

How could researchers use TMS to demonstrate different functions of parts of the left inferior frontal regions?

^Methods and findings

What are the four main pathways for spoken language processing?

pathway 1: info

pathway 1: brain areas

pathway 2: info

pathway 2: brain areas

pathway 3: info

pathway 3: brain areas

pathway 4: info

pathway 4: brain areas

What is the neural basis for visual language processing?

Symptoms of alexia:

loss of reading ability

What is the neurological basis for alexia?

Brain insult to angular gyrus

Symptoms of agraphia:

loss of writing ability

What is the neurological bases for agraphia?

brain damage to angular gyrus

What is the phonological route to meaning?

Orthography linked to phonology then linked to meaning

What is the direct route to meaning?

orthography directly linked to meaning

What brain areas are involved in the indirect route to meaning in reading?

• Superior and middle temporal gyrus

• Supramarginal gyrus

• Broca’s area

What brain areas are involved in the direct route to meaning in reading?

• Most posterior section of the superior temporal sulcus up into the angular gyrus

• Middle and ventral region of inferior temporal gyrus

• Anterior regions of the inferior frontal gyrus

What is the visual word form area (VWFA)?

Where is the visual word form area in relation to the fusiform face area?

What language functions does the right hemisphere provide in those who are left-hemisphere dominant for language?

• Prosody

• Semantics

• Following a story

What has research on amusia and music perception taught us about language in the brain?

Music and language can be separable

What has research on visual “spoken” language taught us about language in the brain?

Uses same language centers

ASL users may have more right hemisphere involvement

What has research on symbolic language systems taught us about language in the brain?

What is primary progressive aphasia?

How is primary progressive aphasia (PPA) different from other types of aphasia?

Continues to get worse over time