Saturday, 27 April 2013

More on unsteady images, reading speed, dyslexia, dyspraxia and working memory

Unsteady images are possibly major contributor to the difficulties in reading development and hence in dyslexia and probably in the ‘development of IQ’. In that if your system is finding it difficult, taking longer before if it manages it, to create a steady image, then that will be putting more  computing demand on your brain for each ‘unit of look’/fixation.
Also in my previous post on unsteady images , is the idea that to ‘see a letter /word we ‘process several distinct images, in the first 50ms ( I am uncertain about how many milliseconds), and then coordinate them to produce a single intra-fixation image.

Also by inference we acdtually process and coordinate spatially several of these intra-fixation images within each fixation , this in a way is the 'perceptual span'.

This would mean that.....

  • the more unstable the fixation of the eye the smaller the amount of visual data collect within the fixation.
  • The more saccades will be needed to acquire spatial data about a visual scene. More computing power, memory, demand from you central executive is needed for a particular visual task.
  • If for example we think of  a multisyllable word  as a visual scene , then the more unstable the fixation the more computing /brain power or memory will be needed to ‘see’ that whole.
I would suggest that this would delay the development of what is referred to as ‘automaticity’ for that word.

We can  consider the Coltheart Dual Route model of reading   (DRC)   

The automatic matching through the left hand route, uses the orthographic data that will originate in the original mapped visual scene of the word in the lexicon of the semantic system. Unstable  fixation will impact on this system, reducing the probability of a word being held in store there.  This would force the more frequent use of the grapheme-phoneme (decode/blend route).

The effect of this would be a slower reading rate, reduced prosody and impact on the time constraint aspects of working memory.  You are more likely to have ‘forgotten’ the beginning of the sentence by the time you have got to the end.

A further consequence of this stress/demand ultimately on the central executive is that there will be reduced attentional resources available and reduced resources for accessing the long term memory constructs which the text being read impacts on.

This will be most severe when the person is actively trying ‘to learn’ new ideas. Or trying to test the validity existing mental constructs against the new information/data/ mental constructs which the text is introducing them to.

Any aspect of the visual system/phonological system which reduces the number characters per fixation is likely to slow down reading and hence negatively impact study reading performance, self image…………….

If we look again at the DRC, there are three obvious points where phonological processing impacts on the model (The black arrows.) and one where the initially the auditory processing  speed will have an impact ( the green arrow). I say this about the auditory processing aspect because,  auditory prompting of a visual image appears to enable more rapid identification of the image. Also the converse, auditory processing in the hearing impaired is enabled by the visual , lip reading.

At a different scale, we can look at the way uncorrected ophthalmic problems can give rise t a similar reduction in the number of characters processed per fixation.

If a person is myopic ( short sighted) and it is not corrected then they will read more slowly from a blackboard /whiteboard than from a book in a  classroom or lecture theatre.  They are more likely to be disciplined for copying, or having poor attention.. I will develop that idea in another post.

If a person is hyperopic (long sighted) then similar problems arise but the other way around. They will have problems, be slower reading close up and become easily distracted or lose attention when close up than in class work from a board.

The often unconsidered problem is with astigmatisms. This is where focussing on a horizontal line may be slower than on a vertical line.  Refocussing will be taking place during a fixation, processing will be slowed down. The more severe to astigmatism the slower. But the person will usually still be able to read at near and at distance.

I have not considered so far the impact of the reality that most people use two eyes when reading. If one eye is different to the other, the visual system ‘can choose’ to suppress one eye when you read. Normally it will be the one which gives you the most characters per fixation (usually best at focussing on the image).

The reality of course is that may mean one eye for reading a book and writing ( you read as you write)  and the other on a  blackboard etc..

It may be that the system finds managing the direction of two eyes at once more difficult than simply managing one eye. It will suppress one eye.
If not then the image will move in an obvious way which you perceive. Oscillopsia as the system switches attention between the two eyes.( close alternate eyes quickly as you read this if you want confirmation of this effect).

If an eye is suppressed for any reason it is of course still functioning and moving around collecting data. Just subliminally! You will not be aware of it.  But of an image on the retina of your ‘roving’ eye moves cross the retina, it is likely that you system will switch attention to that eye and you will suddenly be aware of the image of that eye and lose the image in the eye you were using. 
All these problems will create attention management problems. And we can see here links with the symptoms of ADD and ADHD.

This roving eye is also likely to be pulling the other eye off its intended target, because of the way the movement mechanisms of the two eyes are linked or ‘yoked’ together. This is likely to increase the difficulties in creating the steady images from the reading eye again limiting the number of characters per fixation with the effects of heightened demand on the central executive and resources available for working memory.

Pretending you have got to the bottom of the page when sharing a book!

Pretending you have got to the bottom of the page when sharing a book!

Thousands of the students I have seen have had the common experience of sharing a book with someone at school and having to pretend to have finished when the other person asks...'Have you finished yet?'
We rarely admit when we haven't! But we do wonder how on earth the other person got to the end so fast! Sometimes when we had hardly got a quarter of the way down the page.

The strange thing is that no one ever talks about it. When the teacher said.

'It will only take 20 minutes to read the chapter for homework.’

What they really meant was
'It only took me 20 minutes' to read it!’

Most people took ages to do the reading. At a study at a local College we found that the reading speed for straightforward text, nothing complicated ranged from 117 to 470 words per minute!

The people who were the slowest were the people who had the lowest qualifications!

But that was reading on white. Things were different when the screen colour was set up for them... personalised.

One person this week went from 210 words each minute to over 700 words per minute. Quite exceptional.

There is nothing natural about reading on a white screen or white paper. But a lot of good readers on white find it really difficult and slower if they have to read on another colour!

Font size is another factor. Most books in schools and colleges are printed in the equivalent of font size 10 or 11.

When testing the students, most read best on fonts of 13 plus.
Try it yourself.

One student at Lincoln University needed a font of 35! he didn’t have an eyesight problem, no need for glasses. He just needed a big font. Some people feet need big shoes for them to walk fast!
Perhaps websites ought to start with a larger font and then people reduce the size if they want to? E A Draffen at Southampton University I am sure would agree with this.

Monday, 22 April 2013

Eyes, eye movement, fonts and reading fluency

What gets in the way of reading text aloud as if you are just talking about the ideas?
Or why do some people sound boring when they read!

A brief list of ideas that we need to understand if we wish to see the dyslexia elephant more clearly

Reading funny stories should be funny.  but people who read slowly often do not find them funny. Also listening to a slow reader, reading a funny story is usually not very funny. The humour is lost.

The timing is poor, the stress on the words inappropriate, they often ignore the punctuation. It is as if they are not aware of the syntax.
BUT… they often make good comedians, stand up comics. In the classroom they are often the class comedian!

They often play music but find reading the music really difficult or simply they cannot.

So possible conclusions are……
Slow readers do not have a problem with complex phonological output!
Slow readers do (may) not have a problem with phonological processing speed, unless it is dependent on the visual processing of text to start with.

So I will explore the relationship between reading speed and the quality of the reading.

This is a list of ideas that should be raken into account. To be examined in more detail another day.
Fluent readers read faster than slow readers.

Slow readers can read fluently.

Fluent readers can read slowly.

Fluent readers see more words per fixation.

Fluent readers read more complex text more slowly.

The speed of reading (in alphabetic scripts) is dependent on how many letters your eyes can ‘see (process) at the same time’… Facoetti.

The number of letters you can see at the same time depends on crowding effects (character proximity)…Facoetti

The reading speed depends on visual attention span…. Valdois

The visual attention span depends on reading fluency.

Perceptual span depends on reading experience/automaticity
Perceptual span depends on the novelty of the syntax.

Perceptual span depends on the complexity of the text.

In alphabetic languages the syntax is explicit in the word sequence
In an ideographic language the syntax is sort of implicit in the word 
sequence and often a product of review or parsing after first reading pass of a sentence.

In ideographic languages all character spaces are equal. There are no character spaces indicative of word endings/beginnings.

In alphabetic languages reading speed/fluency is reduced if word space is the same as character space.

Recent work is investigating the introduction of word spacing into simplified Chinese.

Dyslexia (as defined in cultures using alphabetic languages) appears to be rarer when the first language is ideographic.

Dyslexic people appear to read more slowly (and be less fluent) when reading text which has been justified.
In alphabetic languages reading speed/fluency is reduced if word space is the same as character space. Dyslexia (as defined in cultures using alphabetic languages) appears to be rarer when the first language is ideographic. Dyslexic people appear to read more slowly (and be less fluent) when reading text which has been justified.

In the justified text above the letter spacings are more varied than none justified.

When a person is used to a particular font there is likely to be information concerning letter spacing variables built into the algorithm to read that font. Changing the font to a new font will give rise to a need for more spatial processing by the cortex and slow reading down initially.

Reading speed development is faster in transparent (phonically consistent alphabetic languages) languages compared with opaque languages.

Dyslexia is rarer in countries with transparent languages.

China has introduced pinyin as an alphabetic transparent language with word spacings.

Saccades during fixation use visual data from perifoveal and peripheral retinal data.

Crowding effects become greater as you move away from the fovea.

The cone cells become larger as you move away from the fovea
Spatial data becomes coarser as you move away from the fovea.

Crowding is initially reduced as font size is increased particularly critical in the perifovea and periphery.

According to some reading theory, the number of saccades needed and hence the length of the saccades depends on the rate of grapheme-phoneme matching as the image becomes eccentric to the fovea.

For multi word fixations the grapheme-phoneme match of the next word in the word sequence needs to take place before the burst neurones instruct the occulomotor muscles to ballistically move the eyes so that the image of the centre of attention needed next word is focussed on the centre of the fovea
This aborted saccade response will repeat until the grapheme-phoneme match takes longer than the saccade calculation and instruction process.

The rate of grapheme-phoneme matching depends on the 
1.  The frequency of exposure to the word to be matched. (new words and non words take longer)

2.  The eccentricity of the image from the centre of the fovea.

3.  The diameter of the fovea.

4.  The size of the cones in the fovea.

5.  The rate of image creation in the ‘mind’

most of this is about integrating spatial and temporal data..

Please add more to the list in comments,

Saturday, 20 April 2013

Unsteady images / blurring /letter spacing effects. Possible reasons.

Reading performance and visual processing: What appears to happen in the first 50ms of you seeing a word?

Recently I took part in a pilot study looking at crowding and ‘colour’. Further study will start again this summer.
I learnt a great deal from this initial study.
It required the ‘subject’ to look at a computer screen and then a letter T would appear.
The T would be upright, upside down, laying to its right or laying to its left; as below.

The letter was displayed for 50ms and then had to decide which way round it was.
What I did not expect was that I would ‘see’ or ‘perceive’ four or five letters from that 50ms. As below.

During the 50ms, of course my eye was moving relative to the screen, as a result of muscle tremor in the eye muscles, neck muscles and back muscles.  I had seen this movement in the eyetracking, but not appreciated its importance.

My visual system was recording positions that I was conscious of, as an overlapping image about every 10ms.

So if we consider say a couple of words next to each other. The visual data my brain was trying to cope with would be similar to that below.

The two words are actually

The gap between the words is obviously important to stop the words over lapping allowing the system to identify it as two separate words...

Another experience was this. In setting up the experiment, before I was aware of this effect, we had to decide on how many milliseconds the letter T would appear on the screen for.  At longer exposures I was NOT aware of several images. I perceived a clear letter T.

There were four of us in the pilot and it looked like each person took longer for the brain to compute a clear steady image.

What has this got to do with the theories about the origin of developmental dyslexia?

This was very much a visual experience which would limit the phonological output.

It concerns the way in which the spatial information and timing information about the image are computed by the brain. 

That is there are several competing images, collected in sequence during a fixation, the relative position of which are a consequence of small movements on the retina of the eye. These relative movements will be caused by slight changes in muscle tone controlled by or as a result of signals from the cerebellum.

The cerebellum is closely linked to the magnocellular system and this phenomenon can easily be linked to motion processing efficiency. Ideas developed by such as John Stein and Al Galaburda

When the background settings were changed, the clarity/ singularity of the image appeared to change.

The nearby presence (and closeness) of other letters (crowding) changed that perception of ‘singularity’.

This fits closely into Facoetti’s ideas on visual crowding and reading and Valdois’ ideas on visual attention span.

It also fits some of the ideas associated with the Meares-Irlen syndrome.

More work needs to be done.

Friday, 19 April 2013

Do we really decode words sequentially?

Do we really decode words sequentially?

Visual word recognition. The first 250ms.Oxford-Kobe Symposium on the neurobiology of reading.

One of the most interesting presentations at the Symposium was the one by Piers Cornelissen. Cornelissen presented evidence from MEG studies.
These showed that there appears to be a direct coupling/connection from visual areas of the cortex to the Left Inferior Frontal Gyrus. (LIFG) during reading. The methods they used (Partial Directed Coherence …PDC) shows the direction of communication of the link.  The visual areas sent information to the LIFG in the first 130ms of the onset of the visual image.
The LIFG then has direct access to the part of the brain which enables phonological output.

The activation of this part of the brain at the same time as the Fusiform Gyrus suggests that the phonological output is independent of the orthography in fluent readers.

‘Using brain imaging, researchers showed that the speech motor areas of the brain (inferior frontal gyrus) were active at the same time (after a seventh of a second) as the orthographic word-form was being resolved within a brain region called the fusiform gyrus. 

The finding challenges the conventional view of a temporally serial processing sequence for reading in which letter forms are initially decoded, interact with their phonological and semantic representations, and only then gain access to a speech code. .

Why do I consider this important?

My colleagues and I have recorded the phonological output of thousands (over 11,000) dyslexic adults on a default computer screen and on a screen which has been objectively optimised to maximise their phonological output.
We measure their ‘reading speeds’ in several ways.

Aloud and silent…….
Oral reading Fluency…… ORF…   reading aloud complex text

Rapid Automatised Naming……RAN... random short word arrays of a small 
number of simple words... No syntax.

Silent reading only….

Binocular eye tracking….. Recording their eye movements when reading complex text silently.

If this data is analysed for the frequency of particular speeds, there are several distinct modes.  It is multimodal.

Aloud….Default setting.. font 12 Red255  Green 255  Blue 255

Not dyslexic.. ORF……….. 184 words per minute (wpm)
Not Dyslexic … RAN……….184 wpm
Dyslexic…..ORF…….138 wpm
Dyslexic ….RAN…….138 wpm

Silent default settings
Not dyslexic….ORF….460wpm
Dyslexic……….ORF…..158 wpm

Aloud…..Optimised settings (font size and background)

Not Dyslexic…. ORF….219 wpm
Dyslexic………..ORF….158wpm, 184 wpm. and 219 wpm

Silent….. optimised settings

Not dyslexic…..ORF……460 wpm
Dyslexic……..ORF…….158 wpm, 219wpm  and 480 wpm

The idea that these modes are quite robust, suggests that they are fundamental to the neurobiological mechanisms driving the reading process.

The data reported by Cornelissen et al suggest that the visual data arrives at the LIFG 130ms after the visual image data arrives at the retina. This would enable a ‘reading speed output of   462 wpm (60/0.130).

I love the way my work of the last 30 years appears to be converging with the unfolding neurobiology.
I would love to know what the other modes in output we have found actually represent.
I have my hypotheses.  Any suggestions are welcome.

This research can be looked at in the light of the work on visual attention span, referred to in other posts, which will possibly give an insight into the number of fixations needed to deliver the word letter strings to and hence the possible speed of phonological output .

This is also supported by the work of Facoetti et al that the letters are processed in parallel rather than decoded and blended  serially.

'Non words and new words ' would still need to be serially processed but the development of automaticity would be dependent on the visual attention span as implied by the work of Sylviane Valdois et al.
The visual attention span is likely to be controlled by visual crowding.. a visual processing issue.

Monday, 15 April 2013

Musicians and dyslexia. Or not being ‘dysdansic’

Musicians and dyslexia. Or not being ‘dysdansic’

There is debate about the roles of and relationships between visual processing and phonological processing in dyslexia.
This is a short review and a  relevant case.


The case study outlined below reinforces the idea that we should look at two specific subtypes .

1. Where the phonological output is limited by Auditory/phonological processing.

2. Where the phonological processing and hence the phonological output is being limited by visual processing.

The point is that the latter limitation, can be much more easily dealt with than the audiological processing .


At the Oxford-Kobe symposium, last week,  the relationship between these two distinct processing problems has been dissected.
The case study outlined below reinforces the idea that we should look at two specific subtypes.

1. Where the phonological output is limited by Auditory/phonological processing.

2. Where the phonological processing and hence the phonological output is being limited by visual processing.

The point is that the latter limitation, can be much more easily dealt with than the audiological processing .

Interventions which concentrated on Visual processing, such as the Action Video Games research from Andrea Facoetti et al in Italy  and the Auditory processing interventions of Nina Kraus et al, including the use of assistive  devices in this modality,  both appear to have measurable beneficial outcomes in terms of the reading process.

If we look at dyslexic people with a phonological awareness /processing deficit, their appears to be specific deficits.

1.   A delay in rhythm  perception in the neuro studies… This group appears less able to ‘match’ a rhythm which they ‘receive’.

a.   So for example to be able to tap you fingers in time with a drum beat.
b.   Or  finding it hard to match body movement., such as in dancing, to the beat of the music. ( sounds like me! I feel Dysdansic.
c.   This would make it almost impossible to participate a ‘Jam session’ if you were wanting to be a Jazz musician.

2.   A difficulty in identifying changes in tone.

a.   Very robust research shows that the auditory processing system has a deficit in identifying subtle changes in tone.
b.   Again this would restrict the ability of a musician to ‘play from ear’ but is not quite the same as the rhythm deficit above.

Another relevant issue raised/ reported in the Symposium was that of the origin of the functions of the ‘neural nodes’ in terms of evolution and their relationships in terms of which communicates with which and in which direction.

How does the original function of a node make it suitable for a new role in the ‘reading process’. Looking at the plasticity of the neurobiology.  This aspect it is essential to understand before any assumptions about data from fMRI or MEG studies are used to ascribe ‘causality’ or ‘deficit role.

A particularly good example of this a part of the brain cortex, used when we read, which in preliterate people was used for facial recognition purposes. ( Data from Brazil and Portugal)

Without the preliterate studies the information would have been misinterpreted or rather the significance not understood.

So can I add to this debate about the issue of the role of Auditory processing?

The work By Nina Kraus et al tells us that it is possible, at least in children to intervene effectively in reducing this capability as an intervention and that the outcome is reduced ‘dyslexia’…  By this I mean an increasing in the quality /quantitative, phonological output when reading.

I have worked with several dyslexic adults, who were very accomplished musicians, who had experienced and participated in all the auditory processing therapies unknowingly. 

The common experience of all of them was that they could not read music!
I include in today’s blog a detailed case history of one of them.

This guy is a skilled craftsman, a joiner, a keen successful sportsman, an accomplished musician who was able to hear and then play music at a high level.    We have to assume than that he would not show up in testing as having an auditory processing problem. What he DID HAVE is a phonological output/processing problem. He could not read effectively aloud, there was no effective prosody, it was tiring. His good friend is the optician I am working with.

( As an aside Ken Pugh, at the Symposium assures me that it is getting very close now to the effective ability to measure Prosody. As far I and many others are concerned this is what really matters. When we use reading speed or oral reading fluency measures what we are really trying to influence is prosody. The quality of the phonological output…. More later on this topic.)

 Following a comprehensive removal of limitations to his visual processing skills. Ian now reads music! And reads text fluently and easily with a great deal of pleasure.

The introduction refers to two case studies. Detail from the other study will be provided in another blog.

1.1.  Function of this study

It is recognised that the reading ability of a nation controls the academic performance and ultimately the economic might of a country.

Despite the best efforts of educationalists with young people and adults there is little evidence of any actual change in the reading performance of the population over the last few decades.

This study is associated with the development of a programme which seeks to remove, where possible, any limitations by visual components to the reading performance of an adult population.

It is hoped this study will contribute to the debate on the interventions available and the role of visually enabling individuals.

The interventions studied here are intended to complement, not to replace, other supportive technology and strategies developed in the teaching/support of adults with restricted reading, visual stress or dyslexia.

The development of the computer screen over the last 30 years has, for the first time in the history of literacy, made it possible to ‘fit’ the reading material to the eyes of the reader. It is now simple to move away from the default font sizes and prescribed background settings to use the large 16.5 million colour palette and the extensive array of font sizes available within standard computers to offer people specific solutions to maximise their performance.
The computer screen parameters which can and will be objectively optimised for each individual in this analysis are,

·        Font size
·        Screen Brightness
·        Background red/green pixel brightness ratio.
·        Blue pixel brightness.

1.2.  Background to the study

It is accepted that the quality of a person’s reading performance is often the limiting factor in their academic and life chances.

The main approach with dyslexic adults is to provide technologies and strategies enabling the individuals to participate fully and successfully despite difficulties in reading performance and other attributes.

If the adult is not diagnosed/labelled as dyslexic then protracted efforts are made to improve their level of ‘literacy’ or reading performance.

These case studies seek to evaluate the effect of available visual interventions on the enhancement of the reading performance of two particular adults. This is not to teach them how to read better, but to enable them to read at a higher level of performance, more effectively and hopefully enable them to participate more fully in learning.

The discussion tries to place the implications of these outcomes into the debate on raising literacy standards.  This is not primarily concerned with teaching; it is more aligned to the analogy of providing well fitting shoes so a person can walk more comfortably, for longer and with more pleasure/less stress.

It is hoped this will add to and inform the debate on maximising reading performance for individuals.

OmniRead is involved in collaborative work at colleges in Yorkshire where a programme of maximal support is being developed to enable the students’ literacy levels/reading performance to be maximised to empower them to make best use of the courses on offer.  This work is in conjunction with a team from a large university department of optometry. 

1.3.  Structure of the case studies

The data collected will attempt to disentangle how the components of the interventions contribute to the improvements in reading performance experienced.

The reading performance was measured in terms of

·        Eye movement data showing the way the eyes saccade and fixate on the text during reading
·        Rapid automated naming
·        Oral reading fluency
·        Silent reading performance of complex/meaningful text

The eye movement data was recorded using the ASL X-300 binocular eye tracking system allowing free head and body movement during the read. This device identifies and measures, in a relative way, how both the left and right eyes saccade and fixate on the text during reading.

This eye tracker further offers

·        A comparison of the strategies employed by people who experience reading problems with those used by fluent readers.

·        A ‘subliminal’ solution, whereby the reader has no control over the process which is consequential of the visual strategies adopted by the person’s brain to maximise the reading performance within the limitations of focussing, extra-ocular muscle (orthoptic issues)  management and prior total reading experience.  This can all be considered further within the context of such models as the  “E–Z Reader: A cognitive-control, serial-attention model of eye-movement behaviour during reading”

The use of a binocular eye tracker with a typical fluent reader gives rise to graphs similar to those shown below in graph 1. In this case the person had not had, to our knowledge, a full optometric and orthoptic correction. 
Each saccade and fixation is clear and the two eyes are fully coordinated except for the fixation disparity (the difference between the two eyes and denoted by the bottom green line) which appears to be increasing as they read.
The neat step-like pattern is typical of a fluent reader.  If the fixation disparity was constant, then the person is likely to have an even higher level of reading performance. The increasing fixation disparity feature suggests the individual may be prone to being easily distracted during reading /writing

If at least one eye appears to be undertaking these clear steps, the person is likely to read quite fluently although not necessarily with a great deal of stamina. 

1.4.  Rapid automated naming (RAN)

The use of RAN data in the study of reading performance has a long history. Such data being the bedrock of the work by Arnold Wilkins et al in the work on the benefits of the use of coloured acetates and coloured glasses in reading. In his original work on the Irlen process and in his work on developing the intuitive overlay system for identifying who might benefit from the prolonged use of acetates or glasses while reading, the published research demonstrates that the gains in reading performance associated with ‘intuitive colour preference’ were not placebo effects.
RAN performance was also important in the development of the Phonological Deficit model and the Double Deficit Model. 

1.5.  Oral reading fluency (ORF)

This is a measure of the speed of a person reading real text aloud in meaningful sentences and measured in words per minute.
In this study both subjects read all of the words in the test. What varied, in addition to the speed, was the disjointedness and prosody of the reading – fluency. These latter two points can be heard and contribute to the speed but were not measured, but the changes in fluency were noted on a qualitative basis.
The ORF is considered to be a good indicator of potential academic performance. In our work with adults at University, using the same text material, the mean ORF for dyslexic undergraduates is 138 words per minute whereas for the non dyslexic university population it appears to be around 184 words per minute.  These figures vary depending on the institutions and appear (from our data) to be related to the average A level grades needed to gain entrance to the institutions. Curiously, at university level the mean figures for RAN and ORF appear to be very similar, however those with ‘reading difficulties’ tend to have higher RAN values than ORF. The rest of the population appear to have ORF values higher than RAN.

1.6.  Expectations before the consultations

Because of the backgrounds of the two subjects it was expected that both RAN and ORF values would be below 138 words per minute. Both subjects had had optometric intervention over a period of time. As a part of this study Chris Coakley undertook optometric consultations looking for any optometric or orthoptic intervention which might assist them. Their original prescriptions and their adjusted prescriptions are detailed below.  Both subjects underwent a colour preference assessment with Intuitive overlays. This procedure was in accordance with the protocols as in Appendix A at the end of this report.

2.       Case study 1 - Ian

Ian is a cabinet maker by trade. He is from a generation where dyslexia was not recognised. He is a long standing client of Coakley Associates of Wisbech.

2.1.  Ophthalmic Intervention

Recently Chris Coakley decided together with Ian that they should apply everything available in optometry to finding out if Ian’s reading problems over the years could be associated with visual issues.
Chris Coakley undertook an extensive study of Ian to identify and quantify any optometric and orthoptic parameters which may have contributed to his poor reading performance.
Before any intervention Ian’s reading performance was recorded using the Wilkins rate of reading test in his present spectacles; the rate was determined to be 67 w.p.m.
The following tests were also performed.
·        A full refraction examination,
·        accurate determination of ADD(The difference between the distance and near prescription ) using dynamic retinoscopy, binocular duo-chrome and amplitude of accommodation tests,
·        eye and hand dominance testing,
·        motility and dynamic fixation analysis,
·        near point of convergence with a ‘RAF rule
·        near phoria with Maddox wing,
·        fixation disparity at near with ADD in place.
The tests resulted in the following optometric/orthoptic outcomes and deficits were identified and a corrective prescription was produced which replaced his original prescription which were
Varifocals        R….+0.75/ -0.5 X90             L +0.75/-0.25X90  Add +1.75
·         Low level hypermetropia and astigmatism attaining 6/5 R&L, with expected ADD for age found,
·         Good near-point of convergence (6cm) but 8 exophoria requiring 2 base in for R.E. according to Mallett which was given, although he is right handed and showed a dominant RE on classic dominancy testing
·         He showed good smooth eye movements on motility testing and had a reasonable score on dynamic fixation analysis (22 sec)
·         Prescription given for reading in single vision form                                                      Right:  +2.75/-0.50x85       Left: +2.75/-0.25x90
 It is expected that correction of these deficits are likely to give rise to improved reading performance because he is now balanced binocularly for both refractivity and orthoptics.
Ian now attained 85 w.p.m. on Wilkins speed of reading test – a 27% improvement.

A pair of prescription glasses was produced using all optometric and orthoptic data.
These glasses were used during the computer screen optimisation consultation with OmniRead.
Using the old glasses and blue/aqua overlay      RAN= 114
Using new glasses and blue/aqua overlay         RAN= 160

2.2.  OmniRead computer setting intervention

This consultation involved the use of a binocular eye-tracker to monitor eye movement during reading using the optometric correction.
OmniRead then objectively calculated the optimal parameter settings for Ian to use on a computer screen, to maximise his reading performance.
Before commencing the optimisation, Ian’s reading performance, using his new glasses, was measured in terms of
1.   RAN (rapid automatic naming) using an equivalent of the Wilkins rate of reading test of an array of simple words in a randomised sequence.
2.   ORF (oral reading fluency) a short piece of text used already with thousands of dyslexic undergraduates and non-dyslexic adults.
3.   Eye movement patterns whilst reading a short piece of meaningful text off a Microsoft Windows based laptop computer.
The default background settings used, namely

and all text was presented at font 12 and in a standard Ariel font style as requested by Ian.
The eye tracker was used to record Ian’s eye movements whilst reading a piece of normal text.

The text used was as follows and presented across the screen in 3 lines.
Text 1
A catering worker is needed for the Maid’s Head Hotel near Filey. You will be working at a modern well-equipped hotel. Experience is preferred but is not essential. You must be willing to train for the food hygiene certificate.  The wage is £5.30 per hour for a six-day week, 8 hours per day. Duties will include food preparation, washing up and keeping the food preparation area clean. This position is available immediately and will last until the end of the summer season, mid-September.
The silent reading results were:

90 words in 29 seconds, or 182 words per minute.

The OmniRead protocols identified the computer screen settings as noted below for his optimal performance parameters and the following eye traces.

Graph 5: Ian reading using his optimal computer settings. Note the greater step-like performance.

The right eye (blue line) appears not to be closely teamed with his left eye under these reading conditions.

What is interesting is that the fixation disparity appears to increase to the
 same ‘value’ (around 250 units) but on the optimal background this seems to have been reached in about half the time that it did on default. There does however appear to be a discrepancy between the eye movements of his left and right eye; the right moves more (the vertical range) compared to the tighter, more confined, left eye.

To avoid any learning effects, a similar piece of normal text was used to identify Ian’s reading speed using his new optimal conditions as noted above.

Text 2
A special police team begins a different beat today, swapping their
cars for a boat. Three officers will spend the summer protecting
holidaymakers along the 200 kilometres of rivers and lakes which
make up the Norfolk Broads.
The team’s main role is to advise holidaymakers on safety on the
water and to protect their boats from thieves.
The scheme has been made possible because of the generous funding
by local businesses. They have raised the thousands of pounds
needed to purchase and run the boat for the police.

The data obtained was as follows,
88 words read in 18.7 seconds or 282 words per minute.

During the measurement process, data for the oral reading fluency (ORF) was taken using text as used daily with undergraduates. In addition timing data was also recorded for Ian to silently read the text.

The next graph shows the effect of using his optimal glasses reading complex text initially on a white background with default font size compared with reading equivalent text with optimised background and font size

Using everything we could give him his reading performance was better than the average non dyslexic undergraduate which is 184 words per minute.

At 195 words per minute, it is likely that his reading performance was being limited  by the bio mechanics of the act of reading aloud. A second measure was taken that of the silent reading of complex text. At this speed the fluency/ intonation was at a very high level. Unlike the more stocatal style on the white background.

Finally a reading performance value was obtained under the more normal style of silent reading.  

Using everything with complex text Ian showed a massive 87% improvement in reading performance. From the additional use of optimal font size and colour background. This was benefit not derived from ophthalmic and orthoptic optimisation.
What we do not know from this data is what contribution the latter made to the benefit that can be gained from the screen optimisation
We suspect that it is synergistic.

Graph 6: the step activity illustrating the improved quality of the fixations and saccades.

2.3.  Fixation disparity comparison.

To try and understand how fixation disparity may contribute to visual stress or visual data processing difficulties. A study was undertaken which looked at the total change in fixation disparity occurring in 0.5 second intervals during the reading period. This looks more closely at  binocular instability during fixations. This gave rise to the graph below.
A comparison of the Fixation Disparity index of the default conditions and the optimal settings generated the following graph

Graph 7: comparison of fixation disparity data.
The data from the optimal conditions suggests that the binocular stability during fixations is much more stable and consistent than with the default conditions.. Under default conditions the amount of instability increases throughout the reading period implying increase ‘stress’ in the binocular management process and hence in visual data processing.

2.4.  Comments on Ian’s data

Ian, a mature craftsman, has always found reading hard work.
The combined use of optometric/orthoptic and image optimisation appears to have brought about a notable improvement in reading performance.
The initial very low RAN was improved by 27% by optometric /orthoptic ( optimal glasses with prism) intervention  but this level of RAN is still indicative of person with severe unresolved problems. From our data, dyslexic adults who enter higher education have a mean RAN of approx. 138 wpm.
The reading fluency performance with his new glasses with a default screen setting and font size nearly matches that of the average performance dyslexic adults in higher education - the same level of text difficulty was used with Ian as with undergraduates.
Using the simpler text designed for Further Education, NEET students, his silent reading speed was 182 wpm. Using default settings. This is a strong indication that Ian needed to sub-vocalise which would limit his performance, enjoyment and comprehension. When using his optimised conditions with this simpler level of text there was a substantial improvement in silent reading taking him into a non sub-vocalising strategy.
With the more complex text - longer words more complex phrasing - used for the ORF index, the change was even more dramatic. Initially just using his new glasses the change in reading index with computer screen optimisation took him well above that for non-dyslexic undergraduates (184 wpm) and with such fluency and prosody that is was a clear quantum leap in reading performance with no hesitancy at all. The change in silent read performance with this complex text produced a comparable outcome.
It could be argued that there was an overall performance improvement from the combined intervention of between 100% and 200%.
Whether the benefits from screen optimisation would be as obvious without the optometric/orthoptic intervention is not evidenced from this study… discuss.
Certainly undergraduates who have had unresolved optometric difficulties do not appear to gain as much from screen optimisation.
We do not know yet what will happen after using the combined interventions for an extended period. The issue of whether the magnocellular component of the reading process might be plastic and maintain its responsiveness to the intervention is unknown.  Further consultations may give us some insight into this issue.

2.5.  Follow-up

On re-testing the eye tracking data the next day following its use, the eye turn information was noted.

When using the orthoptic correction (prism) there appears to be no eye-turn taking place as Ian reads, independent of the background settings and font size.

However when using his glasses with no prism component the eye turn appears to be less when using the optimal font size and background.

It is plausible that the eye-turns are to some extent in response to some processing difficulties as opposed to a muscle weakness. This data supports the notion that in this case the eye turn is correctable by orthoptic/optometric intervention but also implies that the background colour setting is a component factor in this ‘strategic eye turn’. This perspective is supported by research by Sue Fowler of the Dyslexia Research Trust shows improved convergence and accommodation when using the Yellow or blue glasses developed by the DRT.

One of the issues that seems to vary with reading performance is the average time duration of the fixations as a person becomes more fluent.  If this is reflective of the speed with which the eye captures enough data to decode the text, then we might expect the fixation time to reduce as the data capture process becomes more efficient.  In the case of Ian this appears to be the situation.
Ian’s mean fixation duration times were

This data supports the notion that the number of milliseconds need for processing  or edge detecting the image/grapheme, is significantly reduced when the background setting is optimised and further reduced if the font size is optimised.