Auditory ERP augmentation-reduction and methylphenidate dosage needs in attention and reading disordered children.

From their event related potentials (ERPs) to tones of four intensity levels, a sample of attention disordered and/or reading disabled children, recommended for a trial on methylphenidate, were classified as auditory augmenters or reducers. The augmenters were blindly titrated at significantly lower dosage levels than the reducers. Moreover, the ameliorative effects of the drug, as assessed by teacher ratings, were more evident in hyperactive augmenters. The children diagnosed either as hyperactive or hyperactive and reading disabled had steeper (or more augmenting) gradients than the nonhyperactive reading disabled and attention disordered subjects. The ERP (N1-P2) gradients were not consistently related to reaction time (RT) gradients to the tones or to an RT measure of nervous system sensitivity. It is suggested that ERPs index registration but not response strength, the first being largely automatic and the second purposive.