Below are the six links in the brain chain that take an idea and turn it into an action. Defects along the chain create common challenges for children in school, according to Dr Mel Levine:

Motor planning

An idea or intention - to write a word, to kick a ball - is converted by the brain into a motor action. Children with a defect in motor planning are often described as impulsive because their brains skip the planning stage and get straight down to the action. They rarely get the result they want.

Processing outside information

The ability to take in instructions and convert them into actions involves a very specific brain function, which some people lack. They may understand verbal and visual information, but have difficulty translating that into an action of their own. The rugby coach explains the manoeuvre, the child understands, but the brain can't send an effective message to the muscles.

Motor logic

Motor logic can best be described as the intelligence of the muscles themselves. Although the brain directs actions such as writing or driving a car, eventually the muscles develop a memory of their own, making these tasks automatic. A failure in motor logic means that the brain is always doing the work and the muscles are always lagging behind.

Motor memory

Described by Russian neuropsychologist Alexande Luria as "kinetic melodies", motor memories are the patterns that your body remembers when faced with certain tasks. Writing never becomes second nature when the body has no "melody" of grammar, letter formation and spelling to replay.

Muscle action

This is the ability to activate the right muscles in the right order with enough speed and stamina to complete the task. A neural weakness in this area is an obvious challenge in many tasks.

Monitoring and Regulation

Your body and brain may get as far as carrying out the action effectively, but if you cannot monitor and assess the action as you go, you may not get the desired result. A student, while writing, needs to take constant stock of what he is doing and whether it is proceeding correctly. Students with faulty regulation can point out their mistakes after completing the task, but can't self-regulate as they go along.