The Learning Disablities Association of America defines dyslexia as a learning disability in the area of reading.

Many famous and successful people have gone public in recent times about their own learning problems - and indeed many claim to have "dyslexia".

As you can see, the term dyslexia is defined in many ways depending upon who is doing the defining.
Obviously we must accept that there is more than one "type" of "dyslexia".

Yet it should not be seen as a disability - rather, dyslexia should be viewed as a different learning ability. Dyslexia only becomes a disability when the condition goes unrecognised and inappropriate teaching methods result in the child's failure to gain competency in literacy and numeracy.^2.

As early as 1925, Dr. Samuel T. Orton had specific ideas in the amelioration/remediation of dyslexia, these included the following two main points of his principles for retraining:-

1. "Training for simultaneous association of visual, auditory and kinesthetic language stimuli - in reading cases, tracing and sounding the visually presented word and maintaining consistent direction by following the letters with the fingers during the sound synthesis of syllables and words".

2. "Finding such units as the child can use without difficulty in the field of his [or her] particular disability and directing the training toward developing the process of fusing these smaller units into larger and more complex wholes."^3.

However, that being said, current neurobiology points to certain specific areas of brain dysfunction.

Reading and writing involves more than just the language areas of the brain. Dyslexia takes many different forms and it's aetilology is just as confounding. The visual cortex feeds information in from the page and the motor cortex is required to activate the muscles for writing. Information must flow freely between the areas concerned or else a form of dyslexia may result.

Some types of dyslexia may be due to what is known as a disassociation disorder - a missing or inactive connection between parts of the brain. Positron Emission Tomography (PET) studies have shown that Wernicke's area and Broca's area do not work in concert in dyslexics and the connectioin between the two - known as the insula - is inactive.^5. Given the implications of these brain areas - the angular gyrus (which links visual word recognition with other linguistic abilities) and arcuate fasciculus (a tract of fibres connecting Wenicke's and Broca's areas which may actually predate speech) may also be involved.

Ratios of males to females in dyslexic populations vary according to the criteria of each study reviewed, but it is generally thought that 2:1 may be an appropriate ratio.^6.

There is increasing evidence that cerebellar deficits may be a causal factor in dyslexia. In a direct test of cerebellar function in learning, dyslexic individuals demonstrated significantly reduced habituation of the orienting response to the conditioned response than controls. This recent study showed for the first time that there are fundamental differences in the way that dyslexic individuals learn.^7.

Generally, there is a high rate of comorbidity in dyslexia. For example, dyspraxia (a developmental coordination disorder), 'night blindness', ADD/HD (Attentional deficits with or without hyperactivity), short term memory deficits, organisational, behavioural and attitudinal problems as well as other specific learning difficulties, indicating that there may be some common biological basis to the conditions. Visual and central processing deficits have been found.

The long-chain polyunsaturated fatty acids (LCPUFAs) are important components of retinal and brain membranes and studies of supplementation with a docosahexanoic acid (DHA) rich fish oil have shown improvements in dark adaptaion and movement skills.^8,9.

Consultation is by appointment only, for further information regarding dyslexia, please contact:-

2. Pollock, J. and Waller, E. (2001). Day to Day Dyslexia in The Classroom. Routledge Publishers, 11 Newfetter Lane, London.

3.Henry, M., K., (1998) Structured, Sequential, Multisensory Teaching: The Orton Legacy. The Annals of Dyslexia Vol. 48, 1998. pp 3-26.

4. Biological Psychology

5. Carter, R. (2000). Mapping The Mind. Orion Books, Orion House, London.

6. Miles, T., R.; Haslum, M.N. & Wheeler, T.J. (1988), Gender Ratio in Dyslexia. Annals of Dyslexia, Vol. 48, pp 27-55.

7. Nicholson, R.I., et al. (2002) Eyeblink conditioning indicates cerebellar abnormality in dyslexia. Exp Brain Res. 143(1):42-50,.

8. Stordy, B.J. (1995) Benefits of DHA supplementation to dark adaptation. Lancet. 346(8971):385.

9. Stordy, B.J. (2000) Dark adaptation, motor skills, docosahexanoic acid and dyslexia. American Journal of Clinical Nutrition. 71 (Supplement1);323S-326S.

10. Thompson, L & Thompson, M. (2003) The Neurofeedback Book. The Association for Applied Psychophysiology and Biofeedback, Wheat Ridge, Colorado, USA.

11. Upledger, J. & Vredevoogd, J.D., (1983) CranioSacral Therapy. Eastland Press, Seattle, Washington. USA.