You Can Learn to Remember: Change Your Thinking, Change Your Life pdfdrive com

sleep, dreams and memory

---

M
any experts hold that sleep plays an important role in the consolidation of
memory. The theory goes that during sleep the brain is relieved from handling
the constant barrage of external stimuli with which it is bombarded during
waking hours. While we are asleep, our minds are free to review, organize and
file the experiences of the day.
There are five stages of sleep: consciousness, drowsiness, light sleep, deep
sleep and dreaming sleep. During periods of dreaming sleep we experience
Rapid Eye Movement (REM): our eyes flutter back and forth beneath our
eyelids, and dreams are particularly frequent and vivid. Several times during the
night we drift down through the five levels and up again – the periods of
dreaming (or REM) sleep gradually increasing in frequency and length. During
REM our heart rate increases and our brain waves are of a similar frequency to
the ones that occur during consciousness (see pp.
32–3
). Research that was
carried out during the 1960s showed that people who were deprived of REM
sleep suffered memory impairment when they were awake. From this we know
that REM sleep is important for the consolidation of memories.
One theory about the link between sleep and memory function is that REM
sleep stimulates the activity of the hippocampus which, during sleep, replays
certain activities or experiences of the day throughout the brain’s cortex (where
memories are formed and stored). This further impresses the memory traces on
the brain, making them easier to recollect when we are awake.
The theory that REM sleep aids our memory is further supported by the fact
that if we have spent a large part of the day learning new information, our need
for sleep increases. Studies have shown that the type of sleep that makes up this
requirement is REM sleep.
Although we cannot be entirely sure of the correlations between REM sleep
and remembering, evidence does suggest that dreams are important for a good
memory. Our periods of dreamful sleep often reveal that we remember much
more of waking life than we think we do. Try searching your dreams for clues
that might be references to your past. Could a child in last night’s dream have
symbolized a younger you? Were any dreams set in places known to you in the
past, but that you no longer visit? Scouring your dreams in this way, can often
prove revealing.