TB7- Brain and Language Flashcards
Which side of VF would have an advantage for naming objects?
right VF as left hemishere Dominant for language in most people
which side of VF would a split brain patient not be able to name an object from?
presented to left VF, as their hemispheres cannot communicate and language is in the left
dichotic listening tasks usually have a _____ ear dominance?
right, as language in left hemisphere (this is for right handers)
Young and Ellis found a ____ visual field advantage for word recognition percentage correct and ____
RIGHT VF advantage for % correct items and reaction times
where is Wernickes area?
superior temporal gyrus STG
Where is Broca’s area?
inferior frontal gyrus (near motor cortex)
What is Broca’s aphasia? (non-fluent aphasia)
symptoms:
speech hard to initiate, laboured and hakted
may only be able to say one word eg tan
meaning preserved but some comprehension impairments
also sometimes see agrammatism and mild articulatory, OR just articulatory problems.- different problems
What is Wernicke’s aphasia? (otherwise known as sensory or receptive aphasia)
symptoms: fluent,articulated speech often nonsensical
impaired spoken language understanding
organising thoughts difficulty
damage usually more extensive
are parietal and temporal dorsal or ventral? Scott
dorsal= parietal ventral=temporal ventral route (auditory to temporal pole) is involved in understanding meaningful sounds/intelligible speech. Meaning is anterior regions, but dorsal route responds to unintelligable (played backwards) - SCOTT
which route does sound repetition engage?
dorsal route- doesnt necessarily activate meaning
which route do familiar words engage?
ventral route
naming familiar objects enages which route/s?
BOTH! meaning would be automatically activated (ventral route) and the phonological form needs to be retrieved for naming (dorsal route)
which routes are involved in the stroop task when naming the font colour?
both routes- dorsal route has the colour name to be pronounced to say it, but the ventral route is activating a different colour- the actual colour seen. TF CONFLICT between them
what is a visual lexicon?
we extract it from words, and is the visual word form about the shapes of letters. most familiar words have an orphoograhic representation
where is global recognition of words happening?
right visual field/left hemisphere (young&ellis)
orthographic vs phonological form-
orthographic is like ‘cat’, how it is written, and phonological /kat/, how it sounds
in which hemisphere is recognition immediate, and which more serial?
left- immediate (where global is)
right- more serial
what type of processing do we use to read non-words?
serial, cannot use global
Cognitive models of reading- dual route model?
dual route- one route for reading nonwords (grapheme-phoneme conversion) which is independent of visual lexicon and meaning. and route 2 through visual lexicon and semantics to phonology.
(sounding out route and semantic route)
Cognitive models of reading- triangle model?
reciprocal links between phonological word forms, orthographical forms and semantics. more interactive and spreads throughout network.
cogntiive models of reading- how similar are their predictions?
similar, but dual route amended to account for phenomena, adding extra links. in original DR model have to access meaning before output, which doesn’t make sense.
which area responds to words?
in fusiform gyrus (occipitotemporal) VISUAL WORD FORM AREA - responds to upper and lower equally, words more than non-words,eg taxi vs taksi
is in left hemisphere and responds equally to left/right VF presentation
criticism of visual word form area found?
controversial- Price argues also responds to objects so isnt specialised.
fmri study that found VWFA- McCandliss et al
whether presented in left or right VF, activity in the left VWFA responds more strongly to words than consonant strings, suggesting word recognition or identification is in left hemisphere.
Dehaene and Cohen- VWFA specialisation results from learning/reading experience
compared literates, illiterates and ex-literates, looked at how brain changes as a result of training. found VWFA responds little in illiterates but a lot in literates. for those with no experience, VWFA doesnt respond to letters but does to faces. Decreases as function of reading experience (more reading>less face activity). same for houses/geometric patterns and opposite with written material.
implications of Dehane and Cohen’s experiment on VWFA?
specialisation results from reading/learning experience. more response in brain to VWFA as get more experience with reading. TF brain may adapt area originally fror objects/faces, to leters and reading.
supporting research for implications of Dehane and Cohens VWFA experiment on specialisation.
blind readers of Braille and signers have WFA. skilled readers also activate the VWFA when listening to words
triangle model interpretation of VWFA specialisation
specialisation leads to establishing stronger links between phonological and orthographical word forms, so when you activate one form the others also activated especially in highly skilled readers.
when else is the VWFA activated apart from reading aloud?
sounding out non words still does (uses dorsal route)
if reading familiar words silently ventral stream activates it
reading aloud engages both streams
Developmental Dyslexia description
difficulty in reading (below age expectancy)
see no issues speaking, has hereditary component, is a phonological impairment (decomposing words into sounds)
not recognised til child starts reading, as with sounds they use global cues/reps. vocab may be bit poorer.
where are dyslexics deficits seen in tasks?
non word repetition
naming pictures (expressive vocab)
and phonological working memory tests
(main issue is in mapping orphology and phrenology)
what do fMRI studies of dyslexic brains find?
deactivation in reading network, especially the phonological route. white and grey matter volume appear different too (anatomical structures and connection)
acquired dyslexia and dysgraphia (inability to write)
appears due to brain damage/stroke. called central when affect the language processing routes (dorsal/ventral) rather than other sensory function like visual processing.
