brain dysfanction affecting languague Flashcards
Marc Dax
claimed left hemisphere was asymmetrically dominant for speech
aphasia
-aphasia is a disorder that results from dysfuction of the brain’s launguage system
-patients have deficits in the use of languague that cannot be readily attributed to sensory,motor or intellectual dysfunction
Broca work
reported the results of postmortem exams of two aphasic patients:they have deficits in the use of languague that were not attributtable to any sensory,motor,or intellectual issues
LeBourgne
one of his patients were called LeBourgne
broca’s study of this patient led him to the idea that the leasioned are was important in languague production
he was only able to say tan after the leason
Broca’s aphasis (expressive aphasia)
individuals are able to understand languague,but have difficulty forming or articulating words
Broca’s aphasia is defined by three core symptoms
1.agrammatism:severe issues using grammar
2.anomia:inability to produce the right words
3.articulation problems
Wernicke’s work
new type of languague disorder:
-deficits in languague comprehension
Wernicke’s aphasia(receptive aphasia)
individuals are able to speak fluently,but they cannot comprehend languague
difference between wernick’s and brocas aphasias
the person can speak perfectly well but they do not understand languague spoke to them
case NB
Ihear everything. I also know what to
do with sounds that are not words. But
when you start speaking, it is like
listening to a foreign language.
Liepmann’s work
showed that apraxia was almost always associated with left hemesphere demage
apraxia
difficulty performing movments with either side of the body when asked to do so,but not when performing spontenly does not effect old motions just new ones
Wada test(Juhn Wada
wada test(sodium amytal test)-how to figure out what hemisphere langugue is on
-administered to paitients prior to neurosurgery to determine side of speech lateralization
-sodium amytal is injected into one carotid artery,this anesthsetize the ipsilateral hemisphere and allows the abilities of the contralateral hemisphere to be assed
ask them to count
it is not always the left hemisphere for languague just most!!
Dichotic listening task
one hadphone is saying a silable and the other another sillable then ask them what they here
FMRI(most often these days)
give a person a probre letter (ex:e)
think of as many words starting with e as possible within 30 s:elephant:extrodinary:exactly
FMRI activation during passive listening
a lot in the frontal lobe when u are speking , when listen a lot on the temporal lobe
factoid
when participants spoke,
a majority opened the
right half of their mouth
slightly more than the
left
it is not true
that lateralization in one side being logic and the other creativity and even the things that have some diffrence is very slightly
latterality and handedness
- left hemisphere dominance for language:88% righ-handed,78 left handed
-ambilateralization for languague:12% of right-hand and 15% of left handed
-right hemesphire dominance for languague:0% of right handers,7% of left handed
sex differences in tarerality
early reserchsuggests males brains are more laterized
more recent evidence fail to confirm this
languague displays the greatest degree of laterality!!
wernicke-geschwind
very localized
wernicke-geschwind
responding a heard question:
primary auditory context(hear)>Wernick’s area(comprehension)>Broca’s area(articulate words)>primary motor(actually sounds the words)
Wernicke-Geschwind Model
reading aloud:
primary visual cortext(read)>information travels to the angular gyrus (translated into auditory form)>Wernick’s area(comprehension)> broca’s area and primary motor cortext for output
problams with this model:
-no aphasic patients have demage restricted only to Broca’s area or Wenicke’s area
-aphasic patients almost always have significant demage to white matter(not part of the model)
-demage associated with aphasia is usally not related to demage to these areas
-fails to consider roles of subcortial structures,like the cerebellum
-incomplete anatomy problems
general finding
large anterior lesions: are more likekly to produce speech/expressive symptoms
larg posterior leasion: are more likely to produce receptive symptoms
current statues
Broca’s and wernicke’s area are importantn languague
expressive aphasia generally results from anterior demage
receprive aphasia generally results from posterior demage
little support for other aspects of the model
Cognitive Neuroscience Approach
1.constituet cognitive process
2.languague areas are not excluided
3.areas are small and widely distributed
when reading
some activity in the right hemisphere mostly left hemisphere though
A Contemporary Network-Based Model
Dual Stream Model: What vs
dorsal streem for sensorimotor intergration (mostly dominant)
ventral streem for speech cpmprehension(bilateral0
happening at the same time=ventral bottom
*impairments of languague:Aphasis
aphasia ussually occurs suddenly,often following a stroke or head injury,but it may also develop slowly,as the result of a brain tumor or neurodegenerative disease
the disorder can impair the expression and/or understandong of languague,as well as reading and writting
aphasia may con-occur with other speech disorders,such as apraxia of speech
severe aphasia
global aphasia -the worst isnt fluent,dosnt cromprehend,cant repeats
aphasias fluent
-Wernick’s aphasia:not comprehend,but can speak fluently(unaware of spoken mistakes)
anomic aphasia
kinda fluent but cant find/retrive words or express words they want to say(not well defined area of the problem in the LH)
non-fluent aphasia
broca’s aphaisa:most common type of nonfluent aphasia,they understand speech and know what they want to say,but they speak in short phrases with a lot of effort
global aphasia
global aphasia
demage to the extensive portions of the languague networks
severe communication difficulties and may be extremely limited in their ability to speak or comprehend languague
Primary progressive aphasia(PPA)
PPA is a syndrome languague capabilities become slowly and progressively impaired
-unlike other forms of aphasia,PPA is usually caused by neurodegenarate dissease
treatments
-speech-languague pathologists(SLP) support patients in regaing their ability to communicatiom
-therapy aims to improve communication by:activating remaining languague abilities,restoring languague abilities as much as possible,and learning to comunication skills
languague can improve for manyb years
factors that influence recovery:cause of injusry,age,extent of demage,genaral health
