ABSTRACT
Several explanations have been put forward to account for the symptoms of AD/HD. Cognitive research has sought to account for impulsive and hyperactive behaviour in terms of, (a) some kind of neuropsychological processing dysfunction affecting the ‘inhibition control system’, and/or (b) temporal processing systems, which act generally or are situation specific, and/or (c) ‘energic’ or ‘state’ mechanisms, hypothesised to influence speed and accuracy of responses to sensory stimuli. Impairment in speed of information processing and ability to focus or select an object for attention is seen as the cause of the symptoms of inattention (Cooper, 1999; Tannock, 1998).
