The last two theories are slightly related in terms of what causes dyslexia. Therefore I thought I’d tell you about them together. I am sure if you’ve gone through this theoretical section with me them you’ve probably had enough of listening to this rubbish. Nevertheless these next two need a little explanation as both theories offer methods to alleviate dyslexia.
The first is the magnocellular deficit theory. It claims dyslexia is a problem related to the processing of moving visual information. The other one is the temporal theory. This argues dyslexia is a problem with the processing of sound in relation to time.
The Magnocellular Deficit Theory:
This theory suggests the cause of dyslexia is rooted in the anatomy of the brain. To be more specific it’s a functional problem in the magnocellular visual pathway. This is one of two pathways that process visual information in the brain.
The parvocellular visual pathway, in our heads, deals mainly with colour and fine detail. The magnocellular pathway’s job is to process movement.
This is where it is claimed the root cause of dyslexia lies. An alternative view is that it is caused by a problem with how the two visual pathways work together. It may possibly be a deficiency in the way they coordinate information.
Of course as with all of the crazy claims scientist make they give evidence to back it up. To make it harder for people to say they are talking out of their Bunsen burners (see evidence).
Well to keep this one short and sweet this theory suggests that what causes dyslexia is a deficit in the processing of sound in relation to time. This may be an explanation for poor sound by sound spelling (see evidence).
This theory also implies dyslexic people have poor short term verbal memories. The best example I can think of is when someone spells out a word for me. I will generally forget the order of the letters as soon as they have been spoken. I will forget the order but not the letters themselves.
At this point I hope you like music. If you don’t the next part may annoy you. The Temporal Theory opens up music as another cost effective intervention for dyslexia (cost effective as in it cost NOTHING). Click here for music based treatment
So, what causes dyslexia? Both of these theories suggest the problem is rooted in the brain. The magnocellular theory claims dyslexia is a problem based in the processing of movement. This may be seen as the processing of time in relation to vision.
The temporal theory argues that it is a deficit of processing sound in relation to time. From this point of view it may be possible for these two theories to coexist. As it may be an overall perceptual problem of time processing in relation to sensory information. Click here to find out about more possible causes of dyslexia.