Some people's Dyslexia may, on the other hand, be caused by changes in the brain resulting from illness or accident - before, during or after birth. These are the environmental factors.

  What ails the Dyslexic's brain?

   Whether because of genetic factors or environmental, the brain of the Dyslexic child gets affected by way of damage, malformation, poor functioning or a delay in maturation.

   Problems such as viral infections, use of drugs, malnutrition and during pregnancy, labor and delivery, or in the early newborn period, may give rise to learning disabilities without mental retardation, by affecting the brain. Such insults on the brain produce defects in information processing leading to various learning disabilities.

  The brain- seat of the mind, seat of language

   All the functions of the mind, including the process of learning, operate by multiple parts of the brain working in tandem. The brain has two separate halves or hemispheres connected by a bridge called 'corpus callosum'.

   The right hemisphere controls non-verbal and abstract functions, art and music, intuitions. The left hemisphere controls logical, deductionistic or mathematical thinking and verbal skills. It is also responsible for understanding (through hearing and reading) and expressing (through talking and writing) of language.

   An area towards the front of the brain (Brock's area) is in charge of expressing language; a location at at the back (Warwick's area) is where understanding of speech that we hear takes place.

   There is a tiny language area in the right hemisphere too.

  Visual and auditory processing

   Language functions operate through meaningful interpretations in appropriate parts of the brain of what is seen (read) and what is heard- 'visual and auditory processing'.

   Dyslexic brains have anatomical differences from normal brains in the 'language-areas' described above, in the bridge between the two hemispheres, and in the connection involving the visual and hearing pathways in the brains.

   The anatomical (structural) deficits give rise to functional deficits in the processing and expression of information. These functional deficits manifest as disabilities in the various aspects of learning.

   With research, the future will reveal why some children learn with ease while others struggle. The group of disorders we call Learning Disabilities may then be separated into the various conditions, each with its own clear-cut cause.