So what is going on in the brain?
The cerebral cortex is the large uppermost area of the brain. The cerebral cortex can be divided into four distinctive areas. These are; the motor area, the frontal lobe, the sensory area and the hind cerebral cortex. As the name suggests, the frontal lobe is situated at the front of the brain. Both the motor and sensory areas are bands radiating across the brain, immediately after the frontal lobe. Behind the sensory cortex is the hind cerebral cortex, where the auditory and visual areas are held deep within the brain itself.
Impulses from sensory organs are relayed to the cerebral cortex by means of a network of pathways of nerve fibres. In the course of growing and learning, the connections between the nerve cells (neural pathways) become established. They are reinforced when the desired outcomes are achieved – for example, a child learning to process the complex series of movements required to pick up a cup and drink from it. Constant repetition allows the planning of these actions to become almost reflexive. Using external sensory input e.g. sight and sound, together with these ‘learned’ patterns of movement, the cerebral cortex is able to judge the best course of action to take. It then sends out the appropriate motor impulses.
The cerebral cortex is divided into a right and left hemisphere, which have specialist functions. They operate in an almost separate fashion. Many functions are ‘shared’, but generally each side appears to work almost independently offering its piece of information to complete the ‘picture’ and therefore forming a whole. e.g. the left hemisphere receives the information, in a jumbled, disjointed way; it is only when the right hemisphere works in harmony with the left that images and actions are interpreted in the correct order and the information is comprehended as a complete piece or object.
Individuals with Dyspraxia do not seem to have both hemispheres responding in this simultaneous, co-ordinated fashion. It is also the development of the two hemispheres that decides whether a person is right or left handed, again this basic development seems substantially reduced and therefore the child may use both hands without preference for some time, thus reducing the development of hand-writing skills still further.
The cortex also surrounds structures known as the ‘thalamus’, ‘hypothalamus’ and ‘pituitary gland’. This area it known as the limbic system. This system is responsible for the ‘instinctive’ and automatic responses within the body: it is also closely linked with emotional behaviour. As the cortex matures is acts to ‘dampen down’ the effects of the limbic system’s emotional output in response to stimuli. If this were not the case, the individual would be highly excitable, over emotional and be extremely sensitive to external sensory input.