Lecture 13: Neuropsychology of Language Flashcards
Agraphia
decline in or loss of the ability to write
Alexia
inability to read
Anarthria
paralysis or incoordination of musculature of the mouth
Paraphasia
the production of unintended syllables, words, or phrases during speech
Wernicke Aphasia
an inability to comprehend or to produce meaningful speech even though the production of words remain intact
also called sensory aphasia
Word Salad
fluent aphasia in which a person produces intelligible words that appear to be strong together randomly
Transcortical Aphasia
disorder in which an affected person can repeat and understand words and name objects but cannot speak spontaneously or can repeat words but cannot comprehend them
also called isolation syndrome
Conduction Aphasia
a type of fluent aphasia resulting from severing fiber connections between anterior and posterior speech zones
speech sounds and movements are retained, but speech is impaired because it cannot be conducted from one region to the other
Amnesic Aphasia
an aphasic syndrome characterized by the inability to name objects and by the production of unintended syllables, words, or phrases while speaking
Expressive Aphasia
non-fluent aphasia involving a severe deficit in producing language
also called Broca’s aphasia
What are phonemes?
fundamental language sounds (“p; b; sh”)
What are morphemes?
smallest meaningful units of words (“dog”, “unbreakable”)
What is a lexicon?
collection of all the words in a language (vocabulary)
What is syntax?
meaning of words and sentences
What is prosody?
vocal intentions
What is discourse?
stringing sentences together to form a meaningful narrative
What is the Wernicke-Geshwind Model?
words read go to the occipital lobe; occipital lobe sends info to Wernicke’s; Wernicke’s will then give carbon copy of info to Broca’s so it can work on a response
question heard goes to temporal; loops into Wernicke’s; carbon copy gets sent to Broca’s
even if M1 is intact, if Broca’s is damaged, words will not be produced
damage anywhere in the model produces different effects in male and female brains
What is aphasia?
complete loss of language
dysphasia?
85% result from cerebrovascular strokes
absence of sensory impairments
perceptual: agnosia
motor: apraxia
thought: autism, dementia, etc.
breakdown between thought and language
What are the problems of classification of aphasia?
few patients
lesion variability: rarely identical or discrete, left hemisphere, perisylvian
production and comprehension depends on many things:
large portions of cortex
complex, dynamic interactions
locating damage which disrupts speech and locating speech are two different things
damage can block connection between Broca’s and Wernicke’s and not the structures themselves
What are the different types of aphasia?
sensory: posterior perisylvian
production: inferior frontal, precentral
conduction: arcuate fasciculus
transcortical sensory: tempoparietaloccipital
transcortical motor: medial frontal
mixed transcortical: frontal and parietal
What is sensory (fluent) aphasia?
also called Wernicke’s or receptive aphasia
prominent deficits in language comprehension
speech production in language comprehension
speech production is normal: normal rate, prosody, rhythm
production errors: especially phoneme & syllabic repetition errors & neologisms (made up words), described as word salad
production sometimes becomes excessive: “press of speech” or “logorrhea”
speech can be semantically empty: e.g., when asked where he lived “I came there before here and returned there”, but makes perfect sense to the patient
What is the area of damage in sensory (fluent) aphasia?
auditory areas of the brain
sensory association areas
What is production (motor) aphasia?
also called Broca’s, expressive, or non-fluent aphasia
main symptom: prominent deficit in production
symptoms range from inability to speak to laborious speech
morphology and syntax often also disrupted, with patients frequently using unaffixed word forms
as well as eliminating adjectives, articles, and adverbs; described as “telegraphic speech”
rely on content words (nouns and verbs)
What are the areas of damage in production (motor) aphasia?
motor areas of the brain
frontal lobes
What is the functional organization of bilingualism?
Kim et al. (1997): distinct cortical areas associated with native and second languages
studied bilingual participants who had acquired second language late in life
used fMRI to “image” working brain while performing tasks in both languages (English and French)
carry out language tasks in the fMRI, should have activation on both sides
only one focus in posterior brain (Wernicke’s area)
more common areas of activation for English and French in later learners
two separate “foci” in the frontal regions of the brain (Broca’s area)
What were the results of the study on the functional organization of bilingualism?
separation of area of activation in Broca’s (production)
more overlap of area of activation in Wernicke’s (comprehension)
demonstrates plasticity
bilinguals who acquired 2 languages in childhood did not have separation in Broca’s area
What is the model for how language breaks down?
- language input
- Wernicke’s (comprehension)
- branches to higher order processing then to Broca’s
- Wernicke’s also sends signals direct to Broca’s (production)
- output of language
What is conduction aphasia?
impaired repetition abilities and severe disruption in repetition of non-meaningful words or sequences
have comprehension and spontaneous speech, but can’t repeat word for word repeats
attempt to correct
aware of disorder
like Broca’s
harder for non-concrete words (proud)
association fiber damage (disconnection syndrome)
hear, “bicycle” - access visual imagery system
hear, “blaynge” - no idea
What are the areas of damage in conduction aphasia?
perceptual word image (Wernicke’s) is cut off from motor image (Broca’s)
cannot repeat nonsense words, can go through other pathways of given a concrete word
damage to pathway connecting Broca’s and Wernicke’s
pathway is not responsible for language, but damage results in language deficits
