Effects of methylphenidate on functional MRI blood-oxygen-level-dependent contrast

Objective: The authors' goal was to determine potential hemodynamic consequ ences of methylphenidate on functional magnetic resonance imaging (MRI) blo od-oxygen-level-dependent (BOLD) contrast. Method: BOLD and perfusion changes were recorded from the motor cortex of s ix healthy subjects while they performed flexion-extension movements of the right index finger (finger tapping) at varying rates before and after oral methylphenidate administration. Results: Functional MRI signals increased monotonically with faster movemen t rates. Subjects' heart rates increased modestly after methylphenidate adm inistration, but no changes in finger tapping performance or functional MRI signals were observed. Conclusions: Methylphenidate does not alter BOLD neural-hemodynamic couplin g. Consequently, functional MRI can be used to map neural systems that subs erve cognitive operations (e.g., attention and executive processes) in subj ects taking methylphenidate.