week 8 final Flashcards
brocas aphasia
difficulty with MOTOR PRODUCTION of words
- labored and hesitant speech, mispronunciation of sounds
- but speech is still meaningful because content words are used
- limited use of function words
- speech sounds telegraphic
- can say automatic phrases
- person is aware of their difficulties
neural features of brocas aphasia
- agrammaticism
- people rarely use grammatical markers
(brocas is activated when learning artificial grammar) - anomia
- searching for the right word
- inability to find a word - articulation
- mispronouncing ewoerds by changing the sequence of sounds
what needs to be damaged?
damage to cortical area is not enough
- damage must include surrounding cortical and subcortical regions
many people with brocas aphasia also have what?
HEMIPLEGIA on the opposite side of the body
- due to the proximity of the primary and supplementary motor cortex
brocas SUMMARY:
an expressive aphasia
- comprehension = good
- articulation = poor bc of telegraphic speech
- repetition = poor
- awareness of deficits
- use of gestures
- automatic phrases are intanct
lesion site
left frontal lobe in the left inferior frontal gyrus
wernickes aphasia
people produce plenty of verbal output, but they have difficulty with receptive speech
- speech contains paraphasias that make speech unintelligible
- involves substitutions or neologisms
- can repeat words but have a hard time understanding what is read or heard
- poor comprehension
- prosody is normal; unaware of deficits
three major deficits of wernickes
- recognition of spoken words
- comprehension of the meaning of words
- ability to convert thoughts into words
pure word deafness
results from damage to left temporal lobe
- people are not deaf. they can perceive and recognize words but cannot understand them
- they can talk, read, and write but sound like a deaf person and cant understand others
- can read lips due to mirror neurons
- cannot repeat words or write what they hear
comprehension of meaning of words and ability to convert words into thoughts result from?
damage to areas that SURROUND wernickes
- posterior language area
- this is the place for interchanging info between the auditory representation of words and the meanings of these words
damage to posterior language area alone (and not wernickes) leads to?
transcortical sensory aphasia
- can repeat and recognize words, but can’t comprehend the meaning or produce meaningful speech of their own
- they know they have heard something but cant understand what was said
- can repeat words but doesn’t understand them
- suggests a direct connection between wernickes and brocas
pure anomia
speech is fluent and makes sense, but hard time finding the right word
- speech seems normal in every way, but have a hard time finding words
- when they cant find the right word they talk around it or go in a diff direction
word deafness vs word blindness
deafness
- inability to understand SPOKEN words
blindness
- inability to understand WRITTEN words
when word deafness is more evident than reading impairment
damage is in the superior temporal lobe AND auditory cortex
when word blindness is more evident
greater destruction of the angular gyrus
summary of wernickes
RECEPTIVE aphasia fluency = good articulation = good comprehension = poor neologisms, good prososdy unaware of deficits
lesion site
posterior left temporal lobe
speech capabilities of the two hemispheres
left:
- understanding words and/or linguistic symbols
- producing words and/or linguistic symbols
- MEANINGFUL components of speech
right
- understanding and producing prosody (emotional meaning through pitch, tone of voice, volume, etc.)
- extracting meaning conveyed by tone of voice
- recognition of familiar voices
right hemisphere language functions
responsible for understanding proverbs, metaphors, or the moral of the story
- information you would not know if words were written down
- ability to RECOGNIZE voices
what is activated when people are trying to listen and respond to metaphors?
right superior temporal lobe
language acquisition device
a hypothesized part of the brain dedicated to learning and controlling language
- an inborn aspect of cerebral lateralization of language
- Chomsky’s explanation of children’s readiness to learn language
- why language acquisition is so easy for us
evidence for LAD
both hearing and deaf infants babble in hang movements
- deaf infants babble and proceed into signing in the same stages and at the same pace as kids of speaking parents
- no matter how we learn a language, something in our brain tells us what to do over time and goes through the same process of learning a language
what part of the brain is ASL activating?
people born deaf use the SAME parts of the brain when using sign language to produce and understand language as those using spoken language
- regardless of how lang is conveyed, the neuroanatomical location of the involved structures is the SAME
recovery of language function
for left hemisphere damage:
early in life: right hemisphere can take over language functions since it is already responsibly for prosody and figurative nature of lang
- later in life language control shifts to bordering areas
critical/sensitive period of lang acquisition
explains why young children can learn many languages with ease
- difficulty post-adolescence learning a second language
- if deprived of contact during this period, the person will not be able to learn language
- when kids learn 2 langs at the same time in childhood, the same areas of the brain are activated when they use either language in adulthood
bilingualism and when languages are learned
depends when the second language is learned
- if new langs are learned after age 11, diff regions of the brain are used for each language
billingualism and arriving in the US
arriving earlier in the US = more proficient english speaker
- after the age of 7 you cant learn English like a native speaker bc the brain no longer is able to accept a new language
- if you don’t get exposed to language early as a child, these people never develop lang even if they are rescued between 7-11
what types of brain injury can cause pure word deafness
disruption of auditory input to the temporal cortex
OR damage to the superior temporal cortex itself
- disturbs the analysis of sounds of words and prevents people from recognizing other people’s speech.
evolution of language
speech and lang may have been built on a system originally controlling gestures of the face and hands (hand movements facilitate speech)
language genes
FOX2P is the most researched
- a mutation of this gene results in reduced gray matter in Broca’s, along with articulation difficulties, problems identifying speech sounds, grammar probs, and understanding sentences
- human versions have been found in Neanderthal remains
conduction aphasia
speech disorder that occurs when the connection between brocas and wernickes areas are damaged
- shows that there is a connection
- results in meaningful, fluent speech and good comprehension, but impairment in REPETITION OF WORDS
- cannot repeat it but may understand and give you a different or similar version of it
- may also substitute words of similar meaning
- hard time repeating nonsense words
conduction aphasia is caused by what
parietal lobe damage that extends into white matter and damages the ARCUATE FASCICULUS
Arcuate fasciculus and second indirect pathway
this is believed to be a direct connection between wernickes and brocas area and used to convey speech SOUNDS and repeat unfamiliar words
second indirect pathway
- locatd between posterior language area and broca’s area based on MEANING of words, not sounds like the first one
