Lateralization of Language Processes Flashcards
what is lateralization?
refers to the phenomenon in which one hemisphere (typically the left) shows greater involvement in language functions than the other
what is split-brain?
a type of disconnection syndrome when the corpus callosum connecting the two hemispheres of the brain is severed to some degree.
what hemisphere is more linguistically sophisticated?
left side
what hemisphere is more efficient in pragmatics and ambiguous words?
right side
where is lateralization present?
- at birth
- in various species
methods for studying the brain?
- Lesions
- Direct stimulation
- EEGs
- Imaging technology
◦ CAT, MRI for structure
◦ PET, fMRI for function - TMS, transcranial magnetic stimulation
what is broca’s area?
LANGUAGE PRODUCTION
portion of the brain contains programs of articulation
◦ Slow, laborious, nonfluent speech
◦ Agrammatical speech (difficulty using grammatical constructions)
what is werkicke’s area?
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
what is aphasia?
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
what type of aphasia is from damage to broca’s area?
non-fluent aphasia
◦ Important for speech production
what type of aphasia is from damage to wernicke’s area?
fluent aphasia
◦ Important for speech comprehension
what are the 7 components of wernicke’s-geschwind model?
◦ Broca’s area
◦ Wernicke’s area
◦ Primary auditory cortex
◦ Primary visual cortex
◦ Primary motor cortex
◦ Left arcuate fasciculus
◦ Left angular gyrus
what is Left arcuate fasciculus?
◦ 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
what does damage to Left arcuate fasciculus results in?
Conduction aphasia – difficulty repeating heard words
what/where is Left angular gyrus?
◦ Behind Wernicke’s area
◦ Associates visual language stimuli with phonology
damage to Left angular gyrus results in?
- Alexia – impairment in ability to read
- Agraphia – impairment in ability to write
wernicke-greschwind model responding to a heard question?
- Primary auditory cortex
- Wernicke’s area
- Arcuate fasciculus
- Broca’s area
- Primary motor cortex
wernicke-greschwind model responding to reading aloud?
- Primary visual cortex
- Angular gyrus
- Wernicke’s area
- Arcuate fasciculus
- Broca’s area
- Primary motor cortex
lateralization in the left hemisphere?
◦ Very important role in language and much language functioning occurs here
◦ Large role in syntactic abilities (for both spoken language & ASL) and phonological processing
lateralization in the right hemisphere?
◦ Right hemisphere disorder: can affect discourse processing, pragmatics, prosody
◦ can read and understand individual words
what are the “Dual stream” models of
language processing?
Broca’s and Wernicke’s areas into two
streams
- dorsal stream
- ventral stream
what does the the dorsal stream do?
associated with phonological processes
what does the ventral stream do?
associated with semantic processes
how is language implemented in the brain?
- 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
what is the importance of the wernicke-greschwind?
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
