Week Ten - Biological Basis of Communication Flashcards
Gender differences of language?
females begin talking earlier, better verbal memory, reading and spelling, more fluent, but less lateralized
What declines with age?
ability to acquire language
Language-related biological events can only happen during…
the critical period
lateralisation of language occrs when?
during childhood
What does neuroimaging allow?
allow insight into living brain processes
What is the subtraction method?
Main method used in brain imagining
Participants carries out one task, then does a variant of that task, subtract image of one from image of other to identify where critical difference is located
Problems with subtraction method? 4
Its difficult to find appropriate comparisons
areas may be active without being critical
functions may be inconsistently located across peoples brains
cant always tell what high activity means for processing
ERP’s?
Electrodes are placed on the scalp to record activity of the brain.
- present a stim
- measure voltage changes
- examine time course of brain activity during task
Temporal vs spatial resolution in ERP’s?
good temporal, poor spatial
MEG?
measures magnetic activity in the brain. difficult and expensive
Temporal vs spatial resolution in MEG?
good temporal and spatial
CAT?
x-ray images taken from all angles around the brain, produces integrated image of medium resolution
Temporal vs spatial resolution in CAT?
Neither great nor bad spatial and temporal
PET?
radioactive glucose injected into blood.
given a task, detectors measure where the glucose travels to/used, produce 3d model of the brain
fMRI?
measures energy released by hemoglobin in the brain areas using the most glucose
Temporal vs spatial resolution in fMRI?
good spatial, reasonable temporal
PET, fMRI and ERP?
fMRI not as good as ERP but more precise than PET
TMS?
powerful magnets stimulate the cortex, recording physical response
How is TMS different from all other neuroimaging techniques?
It is the reverse, causes brain activity rather than observing it
Aphasia
Loss of ability to speak
Broca’s aphasia?
non-fluent
slow, laborious, hesitant, little intonation, articulation problems - DEFICIT IN SPEECH PRODUCTION
can understand language
Wernicke’s aphasia?
deficit in speech comprehension
long utterances that make little sense; filled with nonsense words
- fluent but nonsensical
- adequate syntactic structure
- function words in tact, content words hard to find
- poor comprehension
can’t understand own or others language
Modern conceptions of Broca aphasia?
deficits in
- syntax
- passive sentences
- determiners
Modern conceptions of Wernicke’s aphasia?
speech is incoherent
poor semantic judgement (eg dog, cat, turnip)
Pure word deafness?
lesion disconnects wernicke’s area and heschl’s gyrus (audition).
can hear but can’t understand due to no auditory signals not getting to wernicke’s area
Conduction aphasia?
lesion damages the arcuate fasciculus; discomments broca and wernicke area
can hear and understand, but cant repeat what they hear
Agrammatism?
Deficit in sentence construction (cant put words in right order)
- content words preserved, function and inflectional endings not so much
Jargon aphasia
extreme type of fluent aphasia, major word-finding problems (syntax intact)
Jargon aphasia two common symptoms/experiences?
Paraphasia: substitution of content words
Neologisms: made-up words
Anomia?
impairment retrieving names of object
occurs due to damage to angular gyrus
Two types of anomia?
Lexical semantic: Patient can name members of one semantic category but not another
Phonological anomia: Problems retrieving phonological info about a word (know what it means, TOT phenom)
Garrett’s stages of syntactic planning explaining agrammatism?
trouble translating between levels (functional and positional)
- no sentence frame constructed
- no function words retrieved
Garrett’s stages of syntactic planning explaining jargon aphasia?
can link to functional level to positional level but cant get the content words (in F level)
Double dissociations between?
word finding + syntax production
syntax comprehension + syntax production
morpheme access + syntax production
retrieval of phonology + retrieval of content words
