Friday, 14 December 2012

Story of John, a dyslexic young adult

I make no apologies for the technical nature of this blog. John wanted this written down for others to read. It is not his name but in a way it could be the story of thousands of people in this and other countries.
It will continue to be re-enacted across the world until this issue is dealt with logically and effectively.

John did not recognize that he had ‘visual stress’ issues but volunteered for a 1: 1 session to enable him to read more effectively.
He had actually been diagnosed as dyslexic when in Primary school. At secondary school there was a breakdown in his relationships with teachers.  By mid day his reading capability had virtually collapsed.
 He did not wear glasses but had been to an optician when he was 11 years old at the beginning of secondary school, because he was experiencing headaches by the end of the school day.
He was told by the optician that he had good eyesight, in fact exceptional, and was not prescribed glasses.

John had to turn his head sideways to prevent his left eye aching when he read.  Similarly he needed to turn his head slightly sideways when looking at you. 

In class he needed to sit on a particular side of the class to be able to concentrate.  He would regularly be admonished for reasons he did not understand, indeed for actually concentrating because the teachers misinterpreted his behaviour.

At 13 he had left with his parents for Spain, where he no longer attended school.
A quick Visual assessment of John

A rudimentary check on John’s vision identified the following issues.
1.    His left eye was short sighted with a far point (loss of focus) at around 70 cms.

2.   The left eye demonstrated significant astigmatism.

3.   His right eye appeared to have no refractive issues but he had been told that it was ‘lazy’, suppressed.

We do not know what the effect of correct glasses prescription may have had on John’s education.
Too often I hear similar stories from dyslexic undergraduates.
Eye tracking data
A 120 Hz binocular eyetracker was used to assess his visual management during reading

The two graphs above show that the right eye (upper graph) is suppressed and not really’ travelling along the lines of text, the saccades and fixations virtually indistinguishable. 

The graph at the end of this blog report shows that the saccades (rapid moves /straight lines on the graph) are not really happening for the right eye! 

By  the third line the right eye is no longer really moving along the line at all This seems to be influencing the left eye a there appears to be a need to turn his head.

The fixations by the left eye show signs of ‘stress with forward and backward drift ‘during picture taking. The graph at the end of this blog shows that clearly.
Baseline reading scores
Using silent reading as a measure of reading performance

It took 25 seconds to read the text which consisted of.102 words 224 words per second.

Reading text used with academically successful age equivalents the rate was 91 words per minute aloud…Long words more complex syntax,

Rapid automatic naming
149 words per minute

There was no evidence of a need for a larger or smaller font. Actually his optimum font appeared to be 12.

Screen background optimisation

Using his optimal background his silent reading speed doubled to around 440 words per minute.

Reading complex text aloud his reading speed increased to 182 words per minute for text which was with familiar vocabulary.

With complex text using advanced vocabulary and syntax his reading speed, aloud increased to 134 wpm from 91 wpm on a white background. Thus is a nearly 50% improvement in performance.

The graph below shows his eye movements when using his optimum settings.

Both eyes are now moving in a similar but not identical pattern.
The above graph was obtained after an initial use of his optimal background gave the following data.

The top graph, his right eye was gradually turning out and there was consistently a great deal of head movement associated with reading.  This test was followed by a series of reads using only his right eye with the optimal conditions.  This has been used in the past with other students and appears to trigger a change in eye movement management enabling better coordination.

Details of eye movement data.

Using optimal conditions the saccades and fixations are more like those of a fluent reader.
In addition the fixations are taking shorter amounts of time. The average time needed is 285 milliseconds. Using default conditions the time needed was 400 milliseconds.

There were also 41 fixations for 99 words 2.41 words per fixation, whereas on default there were for 100 words, there were 85 fixations or 1.17 words per fixation.

  In other words the system was typically processing twice as many words per fixation.  This is possibly the most important factor influencing the improved fluency heard when someone is reading using optimal conditions.

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