Interaction between Phonological processing and visual processing

Interaction between Phonological processing and visual processing

http://anniemurphypaul.com/2013/02/the-link-between-dyslexia-and-the-way-the-brain-encodes-sounds/#comment-23492

The work referred to in the link above is highly relevant o my work.

There is additional evidence concerning what is referred to as Visual attention span, which shows a close link to reading issues and the number of letters that the 'visual/ auditory system can parallel process.

 In addition there is the link to 'perceptual span' which appears to be associated with the number of 'visual spans ' that can be processed within one fixation.

 The first,’ visual span' is likely to be a product of edge detection speed which is associated with another phenomenon called 'visual crowding'. 

These capabilities are most likely 'plastic' to some extent, that is they can be affected by parameters which control the visual image and the 'total reading experience of the person. 

The total reading experience of a person will be a product of.

Their reading speed

1. Their reading stamina
2. Their phonological processing speed, probably limited by Way their Brain Encodes Sounds
3.  Their grapheme-Phoneme matching speed
4. Their syntax prediction capability (Close system capability)
5. Of course their visual systems’ visual span, possibly limited by optometric parameters.

Phonological processing speed may well control the rest when a person is learning to read, but as their reading matures it appears to be no longer the limiting factor for many.

The issues are these.

Is the visual system limiting the rate of the encoding of the link between grapheme and phoneme?

Are what point in a person’s reading development does the visual processing become limiting to performance?

The article suggests that it is possible to improve the encoding process in a child.  This suggests that a child will more rapidly reach the stage where phonological processing is no longer affecting their reading development.

At this point other parameters will become limiting. It is possible that in addition to the training envisaged in the article that optimising the visual factors would accelerate that development further and faster still.

The implication is that the reading performance at any one moment is a product of the two interacting. Work being reported at the Oxford-Kobe symposium in April, suggests that for adults the phonological processing speed is no longer dominating for most people and there is a visual 'deficit' which needs addressing.