A) Average (±SE) path length (m) to reach the submerged, hidden platform on each day, 15 minutes after receiving an afternoon i.p. injection of saline (n=3 High-Active males, n=3 Control females, n=2 Control males, n=2 High-Active females; n=10 total). B), C), and D), Same as A) except for the administration of 0.25 mg/kg d-amphetamine, 0.5 mg/kg d-amphetamine, or 2 mg/kg d-amphetamine, respectively.