We are not going to complete this study with healthy volunteers at this time.

The aim of this study is to test the hypothesis that methylphenidate actively induces emergence from propofol and sevoflurane general anesthesia in healthy volunteers.

Basic science and clinical data suggest that activation of one or more of the brain's arousal pathways is a highly plausible way to induce active emergence from general anesthesia. The investigators have compelling experimental data demonstrating that methylphenidate is highly effective in actively inducing emergence from isoflurane and propofol general anesthesia in rodents. The available literature suggests that IV methylphenidate would be safe to administer to patients recovering from general anesthesia, and that in addition to promoting arousal, it would enhance breathing. Both of these effects would be highly desirable in patients recovering from general anesthesia.

Inclusion Criteria:

1. Age 18-36 years
2. ASA classification 1 or 2
3. Normal body weight, BMI ≤ 30
4. Non-smoker
5. Right handed
6. No history of taking stimulants

Exclusion Criteria:

• In general, patients will be excluded from the study if the state of their chronic health problems gives them an ASA physical status classification of 3 or beyond.