Decoupling Motor Memory Strategies: Effects of Sleep Deprivation and Amphetamine

Abstract

The purpose of this study was to examine motor memory strategies using sleep deprivation as a probe. Eighteen healthy men participated in a three-day study in which they underwent repeated testing on a kinesthetic arm position replication task. On the morning of Day 3, after approximately 48 hr sleep deprivation, they ingested either 20 mg d-amphetamine or placebo. Results showed that throughout Day 3 performance remained relatively unimpaired at medial positions for both groups. For positions shifted 25d` laterally, accuracy was also relatively unimpaired for the amphetamine group but was compromised for the placebo group. It was concluded that sleep deprivation-induced decrements in positioning ability were due to disruption of kinesthetic memory, a narrowing of attention, or both. Kinesthetic feedback, and encoding and retrieval processes of the spatial reference system were preserved.

Key Words:

• Movement
• motor performance
• motor memory
• kinesthesis
• spatial reference system
• spatial abilities
• cognitive strategies
• sleep deprivation
• attention
• amphetamine