Conclusions
Methylphenidate impaired task-switching performance, which can be used as a measure of cognitive flexibility. This detriment may result from degraded outcome signaling within the PFC. This study has implications for the use of MPH in the treatment of ADHD.
Methods
Four rhesus monkeys were given therapeutically relevant doses of oral MPH (0, 3, and 6 mg/kg) while performing an oculomotor switching task to evaluate its effect on task performance. Single-unit recordings in the PFC of two monkeys were taken before and after MPH administration during task performance.
Results
The results show that MPH does hinder switching task performance, an effect that was correlated with a reduction in the amplitude of outcome signals found in the discharges of some neurons in the PFC. Conclusions: Methylphenidate impaired task-switching performance, which can be used as a measure of cognitive flexibility. This detriment may result from degraded outcome signaling within the PFC. This study has implications for the use of MPH in the treatment of ADHD.