Language 2/Hemispheric Specialization

Question 1

What is speech apraxia?

Answer 1

Disorder of motor planning
Specific to planning/coordinating speech sounds

Question 2

What is dysarthria?

Answer 2

Speech motor disorder affecting muscle control
Poor articulation, slurred speech

Question 3

What do speech apraxia and dysarthria have in common?

Answer 3

They are both not an aphasia and not a general language disorder

Question 4

What is alexia?

Answer 4

Inability to read

Question 5

How does alexia occur?

Answer 5

It is an acquired deficit (neurological damage) usually to VWFA (visual word form area)

Question 6

What is dyslexia?

Answer 6

Difficulty/Impairment with reading

Question 7

How does dyslexia occur?

Answer 7

It is a developmental deficit

Question 8

What is agraphia?

Answer 8

Inability to write

Question 9

How does agraphia occur?

Answer 9

It is an acquired deficit

Question 10

What is dysgraphia?

Answer 10

Difficulty/Impairment with writing

Question 11

How does dysgraphia occur?

Answer 11

It is a developmental impairment

Question 12

What does left hemisphere damage in adulthood lead to?

Answer 12

Speech and language problems

Question 13

Where does complex sound become speech?

Answer 13

Heschl’s gyrus (A1)
Speech selective areas
Planum Temporale

Question 14

What do ECoG electrodes on the STG respond to?

Answer 14

Manner and place of articulation
Evidence for speech selective cortex

Question 15

What does the ECoG evidence suggest?

Answer 15

• That higher auditory cortex may be coding for phonetic speech features
• Representation or perceptually relevant aspects of speech sounds

Question 16

What did fMRI studies of reading tell us about the visual word form area (VWFA)?

Answer 16

There was a greater activation for letters than other visual stimuli.
- absent/weaker activation in illiterate adults and dyslexic children

Question 17

What happens when you disrupt the VWFA?

Answer 17

Leads to deficits in letter and word reading

Question 18

What did fMRI studies tell us about the development of the visual word form area?

Answer 18

• VWFA doesn’t show preference for words/letter until children learn to read
• It’s already connected to all the language areas
• Connectivity precedes function

Question 19

What does the vWFA do as far as letters and being engaged in language processing?

Answer 19

It’s robust and specific
Not sensitive to higher-level linguistic features

Question 20

How is speech engaged in language processing?

Answer 20

Robust and specific
Not sensitive to higher-level linguistic features

Question 21

How is high-level language engaged in language processing?

Answer 21

Robust and specific
Distributed processing of meaning + structure

Question 22

What is an N400 response?

Answer 22

ERP response for semantic violations
- prefers incongruent sentences over congruent ones
- Is reduced and delayed in low comprehenders

Question 23

What is an P600 response?

Answer 23

ERP response for syntactic violations
- EX: The cat will EAT or *The cat will EATING

Question 24

Where is language typically located?

Answer 24

Left hemisphere

Question 25

What is anatomical correlation?

Answer 25

65% of brains have larger temporale in left hemisphere (bigger in fetal development)

Question 26

How do I know which of my hemispheres language is in?

Answer 26

fMRI study or Wada test

Question 27

What is a Wada test?

Answer 27

• Inject anesthetic into left or right carotid artery
• When injected into hemisphere that processes language, patient loses ability to understand or produce speech for several minutes

Question 28

What does the right hemisphere do?

Answer 28

• Better visuospatial processing
• Spatial attention (neglect)
• Better face processing (FFA more robust)
• Left motor, left visual field

Question 29

What does the left hemisphere do?

Answer 29

• More language
• Right motor, right visual field

Question 30

How do the hemispheres communicate?

Answer 30

Corpus Callosum

Question 31

What is the corpus callosum?

Answer 31

Giant white matter bundle

Question 32

What are homotopic connections?

Answer 32

Link areas in corresponding locations across 2 hemispheres

Question 33

What are heterotopic connections?

Answer 33

Link different areas across the 2 hemispheres

Question 34

What are ipsilateral connections?

Answer 34

Link same side

Question 35

What happens if there is damage to the Corpus Callosum?

Answer 35

Split-brain patients

Question 36

Who was Patient WJ?

Answer 36

Had split-brain surgery
- no change in personality
- could name and describe visual information presented to his left hemisphere, but not right

Question 37

How do split brain patients behave when “ring” is presented in their right visual field?

Answer 37

Goes to the left hemisphere which is correlated with language then they say “ring”

Question 38

How do split brain patients behave when “key” is presented in their left visual field?

Answer 38

Goes to the right hemisphere which is not as heavily correlated with language and the patient denies seeing anything but their left hand correctly retrieves key

Question 39

What happens when there is a partial resection of posterior corpus callosum?

Answer 39

Sensory information isn’t communicated across hemispheres

Question 40

How are split-brain patients able to complete the task of arranging blocks into patterns?

Answer 40

Left hand (right brain): could arrange easily
Right hand (left brain): failed every time