How do you know if ‘colour will help?’

How do you know if ‘colour will help?’

In the model I have developed, it is not really a ‘colour’ which helps a person. It is the reduction in stimulation of particular cone cell types in the retina; for example the red cones.

Of course you might need a different font size before you notice any difference between them.

The graph above is for a person when their font size had been optimised already and when the screen brightness had already been optimised.

Slight changes in the red pixel brightness had a huge effect on reading performance.

If a cyan filter had been used with a person in inappropriate conditions or the wrong font size I may have not given any benefit.

So to restate.  The reasons a set of coloured filters might not have given benefit can be any one or a combination of the following.

1. Font size wrong
2. Ambient lighting wrong
3. The filters took too much or too little of red, green or blue light out.

As a final point I will consider the blue component of the light.  From our experience, very few people need this reducing compared with say the red or the green.   Most people end up with a sort of ‘mucky cyan’ or a ‘mucky purple’.  What you would call a ‘colour’ something like ‘Rose’ is actually a filter which reduces the amount of green light, and slightly reduces the blue.  A ‘pink’ filter would take out a different amount of green but also a different amount of blue. 

The filter sets used were originally created to test the idea that ‘different colours’ might benefit different people. 

A computer screen is a precise instrument with which to work out/calculate what will work for a person.  It is the best medium to find out what really works.

Why does text blur? One possible reason even with the right glasses

Why does text blur? One possible reason

Text Blurring; Font size and crowding

Many people, who have difficulties when reading, experience perfectly clear text for a few seconds or a few minutes and the letters blur into each other. They then find it hard to see the text. For other people it does not actually appear to all blur but they start to see fewer and fewer letters at once, just the central ones.

When your ‘eyes’ compute the images of letters, one of the difficulties is for the system to identify where one letter ends and the next one begins.  The proximity of one line to its neighbours reduces, or masks’ the ability of the system to compute its existence. This referred to as a ‘crowding effect’. It is a well documented phenomenon of the visual system.

It may well be that this phenomenon is the basis of the blurring effects which large numbers of dyslexic and slow readers experience. 

For each person a minimum distance is needed between the letters to allow the computing of the separate images.

·         To enable the capability to read, to decode, letters and translate into them phonemes.

·         To ultimately blend phonemes and then sound and ultimately spell the word.

This minimum distance is independent of focussing. The minimum distance will vary between people just like their height varies.

So getting this right for a person is absolutely basic. If the letters are too far apart, then this will lead to parts of words or subsequent words being focussed on the retina away from the centre of the fovea to part of the retina where the cone size is much larger and they are at much lower concentrations, increasing the need for more fixations per sentence. This would limit/reduce reading speed. It can also lead to a difficulty in identifying where one word ends and the next begins essential in subconscious control of eye movement.

The first indication of the importance of this letter separation was when Arnold Wilkins announced to me that he ‘had solved dyslexia, you just put the letters further apart!’

This was back in 1998!  It was rather a simplistic statement, but it had great significance.

In Microsoft Word 97, it was easy to increase the character spacing.  Arnold had tried this, I had tried it and a lot of the slower readers did find it easier.

You could argue that a lot of the reason for some fonts being easier to read for some people is really about letter spacing…..The copied lines of text are all in the same font size .

being easier is really about letter spacing…………………..    arial narrow

being easier is really about letter spacing…………………..    Calibri

being easier is really about letter spacing…………………..    Arial

being easier is really about letter spacing…………comic sans

… As well as about the effects of kerning

Unfortunately you cannot do this with a printed book, and it is only some people who find it much easier.

Other variables appear to affect the processing of the edges allowing discrimination between the edges, the ability to separate the letters.  We need to consider possible mechanisms for this.

The data is collected by the eyes oscillating slightly, with cone cells being intermittently stimulated and not being stimulated.   The blurring, fuzzing effects are often only after a few seconds or minutes of reading, suggesting a system with a time/processing component. If the letters are further apart, they do not seem to ‘interfere ‘with each other even after the normal experienced time period.

That could be because the system is not degrading any more or it can keep up.

When the optimal viewing conditions are identified, the subject reports a ‘crisper looking text’ no blurring at default letter spacing.

So what mechanisms might be responsible?

·         The whole process depends on the management of the muscle fibres that create the micro movement which dynamically collects the visual data. Logically   the metrics of this movement must be used in computing the edges,

Of course for the most academically successful usually have very high reading speeds and no reading stamina problems with small fonts. They actually find increasing letter spacing really annoying; slowing them down. There is an unfortunate tendency for high achievers to assume that what is easy for them will also be easy for other people.

 The reality is of course that the majority actually need the increased font sizes and bigger spacing!  The minority are disabling the majority, unintentionally. They do not know any better.

Font size and biological diversity (Font size matters)

Font size and biological diversity

(Font size matters)

Font size is an interesting variable. My colleagues and I have been measuring (calculating) which font size is optimal for each student for a couple of years now. This is an essential component of the protocols we have developed and has to be worked out before we consider other factors.

Most people will think of font size in the context of reading glasses; trips to the optician and deciding which of those lines of letters you can read clearly, or in low vision problems, where a person needs a larger font because of degrading eyesight from issues such as macular degeneration, or cataracts.

Another issue is the tendency to associate larger font size with poor academic performance, low intelligence or ageing.  These associations unfortunately leave a negative feeling and resistance towards the use of large size fonts, when they may be needed by people in the main stream population.

The inverse, the attitude to the use of small fonts, is that as we progress through the levels of education, the texts we have to encounter get increasingly smaller. In higher education there is an assumption that intelligent people can read small fonts. The decision makers (academically successful usually) in society tend to find small fonts easy. This use of small fonts, in itself of course as acts a ‘font ceiling’, restricting access to the higher levels of education to those who can cope with the small font sizes. 

Into this set of prejudices and assumptions appears the issue of wearing glasses. Too often, people assume that ‘the correct pair of glasses will enable a person to read small text. For a young person you can extrapolate this to the situation many schoolchildren find themselves in.

·        They go to an optician because of difficulties they experience with their eyes when they are reading,

• ·        get a pair of glasses,
• ·        go back into class
• ·        Find that they still have problems, often still very severe when they try to read.

They then have two choices.

1.   Carry on wearing them and get called ‘stupid’ because they still find reading slow, difficult and possibly painful.
2. Stop wearing them, and get told off because ‘if you had your glasses you would be able to read’. The teachers regarding them and often making it quite clear, that they believe the child is ‘lazy’, ‘uncooperative’ not interested in learning and probably a trouble maker.
3. 
   
4. But a bigger font size might be all they need!
5. 
   

What I will do now is to try and look at the issues of ‘size’ diversity in the human visual system and start the consideration how this diversity could impact on the ‘font size needs’ of the population.

I will ignore, focussing, assuming that an optician has ensured that the physics of focussing has been dealt with. If the person needs glasses they have them (unfortunately this is often not true).

Physical size/dimension variations between people.

The retina.

The light sensitive cells at the back of the eye are arranged in a hexagonal arrangement (like honey comb).  There are two types.

a.     Rod cells... tiny cells used for night vision. Not used in reading.

b.     Cone cells. larger cells used in reading

c.      This picture shows a part of a person’s retina. The red and green cells are the main ones mainly involved in collecting the image when reading. The blue cells have a role, but there are very few of them and probably mainly concerned with getting the image of the word at the fovea.

d.     Notice that the ratio of red to green cells is unequal and they are clumped. This distribution is thought to be controlled by a similar mechanism to that controlling the stripes on a Tiger. Each person is different.

The cone cells at the centre are smaller than those at the edge and packed very closely.

Right at the centre (the fovea) they are extremely small... There are no rod shaped cells here. Actually the cone cells here are so small they are similar in size to the tiny rod cells.

The diameter of the cone cells and ‘proximity’ or tightness of packing is one important variable which controls how ‘coarse’ the image will be.  . The smaller the cone cells and more closely packed, the more detail.

A bit like the number of megapixels in a digital camera;

The more the better.

The fovea itself, with its tiny close packed cone cells, at the centre of the retina, is the reason why the eyes move quickly from object to object in a visual scene.

In the rest of the retina the cone cells are much larger,  and further apart from each other (more numerous rod cells in between them), getting larger towards the edge of the retina.

The data from the each foveal cone cells is treated independently whereas the data from the rest is processed in groups.

1)   So the way they are wired, the size of the groups of cells, together can vary from person to person.

2)   The size of the cone cells in the centre of the fovea can vary from person to person.

3)   The width of the fovea itself (the zone of small cone cells in the middle of the retina.

4)   The size of the cone cells as we move to the edge of the retina.

5)   The ratio of red to green cells varies dramatically from person to person. Some people have many times as many red as green and vice versa.

If we could give a numerical value to each of the five ‘size variables’ above we can see that there is a dramatic range of combinations in design and in a way the number of ‘megapixels in your cameras’...

For example if we consider the width of the Fovea, the central area of small close packed red and green cone cells.

If a person’s fovea is smaller than the average,

 then the smaller fovea will

a.    ‘Process’ fewer letters per fixation.

b.    More pictures will be needed to get through a sentence. Each ‘picture takes about the same time, about a third of a second.

c.    It will take longer to get through the sentence.

d.   Working memory will be compromised.

Beginnings of sentences may well be forgotten by the time the person has taken enough photographs to get to the end.

There is also what you may call a double whammy here. It is thought that if you have developed a smaller fovea then the cone cells in your fovea will be bigger than for those people with a bigger fovea! 

Eye movement during picture taking

An additional complication is that if the eyes are absolutely steady during a fixation then they stop working completely. They have to be constantly wobbling at very low amplitude so that the image is moving across the edges of the cells. It is the switching on and off of the cells which gives rise to the data that is computed by the brain to create the image. It sort of has to scan the image, the words.

This movement is a consequence of

a.   Muscle  contraction in the neck or movement of the object being viewed

b.   Changing contraction /muscle tone in the six muscles which otherwise move the object on to the fovea. The eye muscles have the job of micro movement of the image on the retina.

c.   All this muscle control is being managed by the cerebellum in the brain and feedback from the muscles themselves and feedback from the computation of the image on the retina. (A link to dyspraxia?)

The amplitude and frequency of these micro movements needs to be appropriate to the size of the cells collecting the data.  If there is a problem of muscle tone management in the eye movement muscles this will change this micro movement in terms of amplitude and possibly frequency.

Essentially all of these variables contribute to not whether you can see a word, but to how many milliseconds it will take for your system to collect enough data to identify the icons/ letter/word you are looking at and match that the phonics/sounds associated with it. That time will depend in addition on what patterns have been seen and identified before and how often they have been seen and identified in addition in the context of language, the syntax from the sequence of sounds which will affect the amount of visual data needed to identify each word.

The reading process (visual data collection and computation, in my world) requires an integrated system affected in its functioning by all these variables and most likely more.

If one is compromised, such as the contribution of head/ neck movement musculature, this is almost certain to compromise/ limit the reading process. Many people with whiplash or upper body trauma find their reading performance diminishes.

I could go on much further, but I will stop here. I hope that you can be aware then that there are considerable variations in the ‘sizes’ of the components of the visual system which influence what size of font will work best for you. Most people reading this blog will read best on around a font 12 or smaller, but in the general population it looks like over half of the people need a font greater than 14 to read fluently for long periods. If you need a bigger font copy it onto a word doc.

I think this needs a mind map!  Any offers?

I will develop these explanations further. For example what is called ‘crowding’ in the next blog.

Neurodiversity.-A biologist’s perspective

Neurodiversity.-A biologist’s perspective

I remember wincing as I sat in the Lecture Theatre listening to a particular lecturer referring to people as being disabled by ‘having neurodiversity’.

I would not have winced if the lecture was about the implications of neurodiversity in way we educate. The way that we ought to start out is by considering ‘mixed capability learning’ or the need to consider that a population of any animal is diverse in design.’

But it is not just about ‘neuro’ diversity; unless by that we include variation in the range and capability of our sense organs.  These are not really plastic. Their design is consequential of genetics and interaction with the environment in a ‘physical way’.

On the other hand if we are really talking about the brain in terms of the way we these days look at MRI scans and extrapolate perhaps too much from them, then we are talking very much about a ‘plastic system’ which develops with us, responsive to the design of our sense organs.  

There is one basic rule in biology. If we treat each person as a ‘system’, that system will always use its capabilities to minimise the amount of energy needed to undertake a task.

For example if the visual system is compromised in any way, then you can expect the connectivity and localised energy usage (what an MRI sort of measures) to modify to minimise effort. When we see an MRI scan then much of what we see will in reality reflect sensory limitations/ capabilities rather than (or in addition to) built in neurodiversity which is genetic in origin.

There was a guy in the 1960’s who had hydrocephalus. The brain was squashed right against his skull, but with appropriate input it was able to function academically at a very high level. It was a plastic enough system to adapt to perform the tasks it was set.

If we modify, enable our sense organs to function more effectively then our brains will adjust to the new data input, if it is easier. 

My work tells me that a font 14 will enable many more people to read fluently. When I think of reading , I think about it in terms of edge detection, computing maximum visual data in each fixation, holding the edge data in memory , maximising automaticity, minimising demand on the central executive (a psychology construct) and hence liberating ‘working memory’ (another psychology construct) using the ideas developed by Baddeley at York.

 We need to consider neurodiversity in terms of maximising the number of people who can access the main means of communication….Text.   That is a visual concept. You can argue that phonological capability is reality predicated on visual performance.   But then who am I? Just a biologist.

Visual data collection problems. Evidence from Binocular eye tracking.

When you measure the way in which a fluent reader’s eyes move as they read.

And show it on a graph. This is the pattern which you see.

If you  look at the eye movements of a person who us having difficulties, sometimes but not always reporting visual stress.. This is the sort of pattern that you see. Basically you would not want to walk up the steps!

 This is actually quite a good one. In the top one the person was using far fewer photographs/ fixations to get through each line of text. This is likely to reduce demand on an already limited working memory if a person is dyslexic.

When a person has their visual stress issues dealt with . The reader at the bottom reads more like the fluent reader. 

There are case studies which I can send out. The explanations get complex.

It has often been said that the eye movements are a result of the phonological problems.

But the case studies show the reverse.  The reading fluency of the people with visual stress issues end up no different to the fluent reader population.

( sorry arial again!)

Should this be ignored?

Dyslexia and functional literacy. Being on the edge

Dyslexia and functional literacy

My blog during ‘Children in Need’ highlighted the existence of over a million students in UK schools every day, who will not be functionally literate as adults. Scaling this for the USA we are talking about 5-6 million children in USA in schools this week.

This 20 % of the population will contain many who could be identified as Dyslexic.  This will be despite opportunity.  There has to be reasons why people find reading difficult and are unable to develop their capability.

Many will be people who should have been wearing glasses when they were young. Or they should have been wearing appropriate glasses. To be honest, I do not know about the USA but here in the UK there is no financial incentive for an optician to really look that closely at a child’s visual needs. Most teachers do not know how to look for the clues, indicators.

Many will be from families where the parent (s) found it hard work as well, so there will be few books and reading material around little academic expectation.  In many homes there is consensus that ‘books and reading does your head in’. It is not fun, not enjoyable; whatever their reading teachers tell them!

Many may have found that when they get glasses, ‘their visual stress’ problems are not solved.  They need more, possibly prisms, different font size, different ambient lighting, and different light mix bouncing off the page or coming out of the screen.

If these other issues or barriers are not removed then their reading will not develop properly, it will also affect what some people refer to as intelligence. In itself a consequence of opportunity or experience. I am unsure of what intelligence is, and what capability is. How do you differentiate between the two? Anyway which ‘intelligence’ do they mean?

A slow runner may be ridiculed or marginalised because they are slow. Being a slow runner though does not put limitations on the rest of your life. It does not cast a ‘slur’ on your brain, on your very being like being a slow reader.

Fast readers rarely have functional literacy problems. Reading speed (Oral Reading fluency in words per minute reading aloud) is an amazingly good indicator of potential academic performance.  If it takes longer to read something, a book, an exam paper, you are not likely to remember how the ideas fit together; usually it goes with misreading, guessing at words and not being able to read for long, or being a slow writer. . 

What the Dyslexic ‘condition’ tells us is that people who are slow readers can demonstrate and develop their capability but they need to learn from others the strategies to get around the reading issues.

Dyslexic people know that slow reading or functional literacy problems do not have anything to do with intelligence. The two are not the same thing.

In a way those diagnosed as Dyslexic are the lucky ones. Most people who are slow readers or have functional literacy problems will be bullied by society into just accepting their place on the ‘edge’. They will be talked at, talked about, accused of being lazy, easily distracted clumsy treated as lesser beings.  The joke is that it is possible to enable people to read more effectively/

As a final point one attempt at this has been /is ‘explicit systematic phonics’. Ok one question.

·         What were the examinations results like for those in the Clackmannanshire experiment when they reached 16?  

Autism, reading and telling the time

Why does there appear to be a visual issue in autism? Many autistic people have difficulty reading a clock face but can read a digital clock. On a clock face it is possible to 'see' the time to come and the time gone by.  Not true on a digital clock you only see 'now'. giving no sense of passing time.  Attention can get fixed on a part of the visual scene making saccading around it difficult. You need to do a visual search with a clock face. To understand the emotions on a human face your eyes need to do a visual search of the human face.
Fluent reading needs controlled attention shifting as you read. Many people identified as autistic years ago turned out to be dyslexic. Many people identified as dyslexic ..........
Is there a connection ?