Facilitation of task performance and removal of the effects of sleep depri - vation by an ampakine (

A hydrodynamic torque converter mechanism having a bladed impeller, a bladed turbine and a bladed stator arranged in a toroidal fluid flow circuit enclosed within a common impeller housing, a friction clutch in the housing including a clutch disc with a friction surface thereon situated adjacent a cooperating friction surface formed on the housing, a stator sleeve shaft supporting the stator, an impeller sleeve hub journalled on the housing, a turbine shaft connected to the turbine and extending through the stator sleeve shaft, and a double circuit flow path for fluid circulating through the torus circuit, one circuit being defined in part by the annular space between the impeller hub and the stator sleeve shaft and the other circuit being defined by the annular space between said turbine shaft and said stator sleeve shaft and by the annular flow space between said friction surfaces.