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. http://tinyurl.com/d8hvt58  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,



1 comment:

  1. Urls for further reading.
    Facoetti et al Crowding and reading..http://tinyurl.com/buovqg5

    Facoetti. visualattention intervention..http://www.researchgate.net/publication/235775013_Action_Video_Games_Make_Dyslexic_Children_Read_Better


    Talcott et al Crowding

    http://www.perceptionweb.com/abstract.cgi?id=v100605



    Valdois Visual attention span http://webu2.upmf-grenoble.fr/LPNC/resources/sylviane_valdois/Bosse%20Valdois%20JRIR_1387.pdf

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