week 10 - language - Broca's and Wernicke's aphasia Flashcards
broca’s area
anatomical definitions not completely consistent
is generally considered to make up some part of a region called “inferior frontal gyrus” (frontal lobe)
in the vast majority of individuals Broca’s area resides in the left cerebral hemisphere
font bottom
broca’s area
role
first idenitifed as playingn a potentially important role in speech production
based on case studies of patients who had damage to the area and displayed deficit in speech
broca’s area
broca’s aphasia
deficit in ability to produce language
reading and writing are also often impaired
language comprehension generally perserved
broca’s area
precise function in language production
still unclear
- not sure what language-related function is lost is cause this disruption
broca’s area
may be involved in:
muscle movements for speech
syntax
grammar
verbal working memory
(all of the above)
broca’s area
damage results in:
understanding good but finding words difficult
intelligence remains intact
wernicke’s area
some debate over location
typically considered to reside in the cortex of the left cerebral hempisphere near the junction between the temporal and parietal lobes
(bottom back)
wernicke’s area
damage results in:
first thought that damage to this region results in a deficit where patients are able to produce speech that resembles fluent language but is actually meaningless
wernicke’s aphasia
patients who suffer do things like:
use made up words
use similar sounding words
(to substitute for another)
to produce speech that makes little sense
comprehension (understanding) is also impaired
wernicke’s area
what did Wernicke propose
proposed a model for language that involved both the region he discovered and broca’s area
Wenicke-Geschwind model
suggests?
suggested that Wenicke’s area created plans for meaningful speech while Broca’s area is responsible for taking those plans and determining the movements (tongue+mouth) required to turn those plans into vocalisations
Wenicke-Geschwind model
too simplistic?
now thought to be too simplistic
language suggests that Wernicke’s area may be involved in speech production rather than just comprehension
it may not be as critical to language comprehension as once thought
—> exact role is still unclear
neuroanatomy of language
based on?
aphasia patients
neuroanatomy of language
broca’s aphasia
comprehension is relatively preserved
deficits in producing language
neuroanatomy of language
wenicke’s area
comprehension is generally impaired
produce fluent but meaningless speech
the challenge of processing language
meaning integration
syntactic (grammatical) integration
language is challenging and complex
the challenge of processing language
meaning integration
we don’t speak in single words
the real challenge and the real uniqueness of language is that you understand and produce multiple words
so have to integrate meaning across multiple words
eg. flat
flat beer, flat note, flat tire
the challenge of processing language
syntactic integration
can make sentences with “dog” “chase” “cat”
- cat chases dog
- dog chases cat
have the exact same words but the meaning changes because of the syntactic roles that the words get in the sentence
the challenge of processing language
language is challenging and complex
dont just retrieve info also have to integrate info
which brain regions underlie syntactic comprehension
see notes for diagram
left side
left anterior fronal gyrus (broca’s area)
- also much bigger part of FC (all the way to pre-motor cortex)
Parietal lobe (above wernickes area)
posterior syria temporal lobe
- the middle temporal gyrus
- superior temporal gyrus
at the back of temporal lobe (wenickes area)
not just left side though!
syntactic comprehension
typically studied?
with a priming paradigm
- 1st time you listen to a sentence big BOLD % change
- 2nd time less of a change
this is the repetition suppression effect that you see when you repeat syntactic structures
use this to see brain areas that support comprehension
syntactic comprehension
typically studied?
what do you see
a much more wide spread network
(not just broca’s and wernicke’s area)
shared syntax in language production and language comprehension
similar network
not just syntax - meaning as well
language related regions
whole temporal lobe plays a role
connections between these areas (white matter)
need the whole network
front
pars opercularis
pars triangularis
frontal operculum
back bottom
superior temporal gyrus
middle temporal gyrus
so what are broca and wernick doing?
memory
integration
so what are broca and wernick doing?
memory
storing linguistic information about single words
so what are broca and wernick doing?
integration
integrating or binding pieces of information into unfolding representation of preceding context