Question:
Such terms include conditions as perceptual disabilites, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. There is also a popular definition used by theNational Joint Committee on Learning Disabilites (1988) which is focused less on educational outocmes and includes a life-span clause. Does this clear up definitonal issues (USA vs UK) or does it muddy the waters further?

Answer: As well as differences between countries definitions there are differences according to whether we are looking from an educational perspective, a pysco-medical perspective or a legal perspective. I was reading up on our mental health act today and the legalistic definition of learning difficulties (British definition) is severely mentally impaired, uses terms like arrested development of the brain and I do not think relates to a real life model It muddies the waters a bit, because it leaves off the part about 'average or above average IQ score'... but I guess because it then says that MR isn't included... but then it says that brain injury is included, but traumatic brain injury is its own category A colleague of mine, with an early childhood brain injury and consequent learning disabilities (US usage), says something similar: "I had an impairment. It was the education system who turned it into a disability."

Traumatic brain injury means an acquired injury to the brain caused by an external physical force, resulting in total or partial functional disability or psychosocial impairment, or both, that adversely affects a child's educational performance. The term applies to open or closed head injuries resulting in impairments in one or more areas, such as cognition; language; memory; attention; reasoning; abstract thinking; judgment; problem-solving; sensory, perceptual, and motor abilities; psychosocial behavior; physical functions; information processing; and speech. The term does not apply to brain injuries that are congenital or degenerative, or to brain injuries induced by birth trauma.