Language II Flashcards
(11 cards)
saccades and fixations
saccades are movements, which are separated by fixations, which brings text into foveal vision
average saccade: 8 letters
average fixation: 250ms
span of effective vision
span of word identification
14-15 letters to right of fixation, 3-4 letters to the left
1 word if its small
letter recognition evidence
- alexia patients
- can’t identify words/letters
- lesions in the left posterior temporo-occipital regions, particularly visual word form area (VWFA) in the left fusiform gyrus - fMRI
- Neuroimaging experiments across languages show word recognition activates this area - priming
- Dehaene et al (2001) used masked priming paradigm using pairs of words with the same/dif fonts
- Found the VWFA was activated regardless of size or shape; it is all about recognition
Dual route cascaded model
Coltheart et al. (1993) proposed the Dual Route Cascaded (DRC) model which actually proposes three routes:
the lexical route (semantic or non-semantic)
- helps with spelling (for familiar words)
- especially for irregular spelling (yacht)
the GPC route
-helps with new words/pseudowords
evidence from patients for dual-cascaded
surface dyslexia:
-fail to read familiar words with irregular spelling (uses non-lexical only)
phonological dyslexia:
-impairments in reading pseudowords (uses lexical only)
other:
Patient WT was able to read words out loud correctly, but had trouble retrieving their meaning (non-semantic lexical route)
issues with DRC
- model overemphasises the role that regularity/ assumes the two routes are hard wired/
- does not allow any flexible learning to occur
- doesn’t account for deep dyslexia patients who experience ‘semantic paralexias’ (e.g. read daughter as sister)
Triangle model
- Orthographic units (visual input: letters)
- Semantic units (meaning)
- Phonological inputs (sound)
- interactive/interconnected
- Pseudowords = O+P
- irregular words = O+S
The model says that connections are stronger for high frequency words == faster recognition (LEARNING)
pros and cons of triangle model
pros
- may explain semantic paralexias better
- allows for flexible learning
cons
- performance is weaker on pseudowords vs human performance
- initially only dealt with words of one syllable etc
where does visual word recognition occur
time frame
Marinkovic et al (2003) used MEG
occipital (100ms)
occipital-temporal (VWFA, 170ms)
then temporal and frontal regions
modern view of language in the brain
- occipital regions
- VWFA
- numerous brain regions and networks
Neuronal recycling hypothesis
Deheane et al. (2001)
we are so good at reading is because we are good at visual processing, a process that is evolutionary older and sharp,
Found that many symbols correlate to aspects of natural images
