Memory processing in and out of sleep

Memories established during learning are re-expressed during sleep. Specific memory circuits can be tagged during learning, and these networks may be reactivated during subsequent sleep using those tags. A complex system of rhythmic brain waves, highly coordinated both in space and time, organizes the reactivation of memory networks, and likely assists in making memories of the episodic type less dependent on the hippocampus. In terms of later memory performance, the sooner sleep-related reactivation follows learning, the better. Yet, some specific memory-related processes do not rely exclusively on sleep. In particular, contextual details are forgotten relatively quickly over time, regardless of sleep or wake. And while periodic brain oscillations during sleep greatly affect what happens to incoming information, alas, the prospect of learning all sorts of useful things while you sleep seems unrealistic.