Lateralization of Language Processes

Question 1

what is lateralization?

Answer 1

refers to the phenomenon in which one hemisphere (typically the left) shows greater involvement in language functions than the other

Question 2

what is split-brain?

Answer 2

a type of disconnection syndrome when the corpus callosum connecting the two hemispheres of the brain is severed to some degree.

Question 3

what hemisphere is more linguistically sophisticated?

Answer 3

left side

Question 4

what hemisphere is more efficient in pragmatics and ambiguous words?

Answer 4

right side

Question 5

where is lateralization present?

Answer 5

• at birth
• in various species

Question 6

methods for studying the brain?

Answer 6

• Lesions
• Direct stimulation
• EEGs
• Imaging technology
  ◦ CAT, MRI for structure
  ◦ PET, fMRI for function
• TMS, transcranial magnetic stimulation

Question 7

what is broca’s area?

Answer 7

LANGUAGE PRODUCTION
portion of the brain contains programs of articulation
◦ Slow, laborious, nonfluent speech
◦ Agrammatical speech (difficulty using grammatical constructions)

Question 8

what is werkicke’s area?

Answer 8

LANGUAGE COMPREHENSION
damage to this area is primarily receptive
◦ Comprehension deficit
◦ Production of meaningless speech
◦ Difficulty comprehending words
◦ Don’t realize what they are saying is nonsense

Question 9

what is aphasia?

Answer 9

a language disorder that affects a person’s ability to communicate as a result of damage to one or more of the language areas of the brain

Question 10

what type of aphasia is from damage to broca’s area?

Answer 10

non-fluent aphasia
◦ Important for speech production

Question 11

what type of aphasia is from damage to wernicke’s area?

Answer 11

fluent aphasia
◦ Important for speech comprehension

Question 12

what are the 7 components of wernicke’s-geschwind model?

Answer 12

◦ Broca’s area
◦ Wernicke’s area
◦ Primary auditory cortex
◦ Primary visual cortex
◦ Primary motor cortex
◦ Left arcuate fasciculus
◦ Left angular gyrus

Question 13

what is Left arcuate fasciculus?

Answer 13

◦ Connections between Wernicke’s area and Broca’s area
◦ Transmits the neural representation of thought to be conveyed from Wernicke’s area to Broca’s area

Question 14

what does damage to Left arcuate fasciculus results in?

Answer 14

Conduction aphasia – difficulty repeating heard words

Question 15

what/where is Left angular gyrus?

Answer 15

◦ Behind Wernicke’s area
◦ Associates visual language stimuli with phonology

Question 16

damage to Left angular gyrus results in?

Answer 16

• Alexia – impairment in ability to read
• Agraphia – impairment in ability to write

Question 17

wernicke-greschwind model responding to a heard question?

Answer 17

1. Primary auditory cortex
2. Wernicke’s area
3. Arcuate fasciculus
4. Broca’s area
5. Primary motor cortex

Question 18

wernicke-greschwind model responding to reading aloud?

Answer 18

1. Primary visual cortex
2. Angular gyrus
3. Wernicke’s area
4. Arcuate fasciculus
5. Broca’s area
6. Primary motor cortex

Question 19

lateralization in the left hemisphere?

Answer 19

◦ Very important role in language and much language functioning occurs here
◦ Large role in syntactic abilities (for both spoken language & ASL) and phonological processing

Question 20

lateralization in the right hemisphere?

Answer 20

◦ Right hemisphere disorder: can affect discourse processing, pragmatics, prosody
◦ can read and understand individual words

Question 21

what are the “Dual stream” models of
language processing?

Answer 21

Broca’s and Wernicke’s areas into two
streams
- dorsal stream
- ventral stream

Question 22

what does the the dorsal stream do?

Answer 22

associated with phonological processes

Question 23

what does the ventral stream do?

Answer 23

associated with semantic processes

Question 24

how is language implemented in the brain?

Answer 24

• There are multiple networks of neurons in different brain regions, which carry out a variety of language functions
• Each processing network is richly connected with networks in other areas
  ◦ including areas involved in more general cognitive processes

Question 25

what is the importance of the wernicke-greschwind?

Answer 25

has served as a very important theory:
◦ Stimulated and directed research and provided a context for its interpretation
◦ Areas of W-G model are important for language