The current study was aimed at (a) investigating the effect of three doses methylphenidate
(MPH) and placebo on inhibition of a prepotent response, inhibition of an ongoing response,
and interference control in Attention Deficit/Hyperactivity Disorder (AD/HD), and (b) studying
dose-response relations for the three forms of response inhibition. To meet these aims, the
following tasks were selected: two versions of the Stop Paradigm for inhibition of a prepotent
response, a Circle Tracing Task and a recently developed Follow Task for inhibition of an …