Lecture notes · Part 3

Sleep on it, remember it

How a night's sleep moves what you learned into long-term memory.

Three ideas today

Memory isn't made in one go

  1. Memory has three stages: encoding, consolidation, retrieval
  2. Deep sleep moves new memories into long-term storage
  3. REM sleep links new knowledge to what you already know

What happens in one night

90minutes, roughly, per sleep cycle
4–6cycles make a full night
7+hours recommended for adults

Without review, forgetting is fast

Illustrative data, shaped like a typical forgetting curve

Same three hours of study

One all-nighter

  • Cram it all the night before
  • Little sleep to consolidate
  • Gone soon after the exam

Three days, full nights

  • One hour a day, quick review at bedtime
  • Three nights of consolidation
  • Still there a week later
Sleep isn't a pause button for learning. It's the save button.
Key idea

Quick check

Which stage does most of the work of moving new memories into long-term storage?

  1. REM sleep
  2. Deep sleep
  3. Light sleep
  4. Being awake

Deep sleep. REM sleep mostly links new memories to old ones.

Match each stage to its job

Encoding
Consolidation
Retrieval
Taking new information in
Strengthening it during sleep
Recalling it when needed

Put tonight's plan in order

  1. Learn the new material
  2. Review for ten minutes before bed
  3. Sleep at least seven hours
  4. Test yourself in the morning

Try it tonight

Ten minutes of review before bed. A quick self-test in the morning.