Wixted determined that a sleep feature known as sleep spindles
- bursts of brain activity that last for a second or less during a specific stage of sleep - are important for emotional memory.
The study -- "Pharmacologically Increasing Sleep Spindles
Enhances Recognition for Negative and High-arousal Memories" -- appears in the Journal of Cognitive Neuroscience.
This effect may be due in part to sleep spindles
, waves of electrical activity that have been linked to memory processing during sleep.
The more sleep spindles
your brain produces, the more likely you'll stay asleep, even when confronted by noise," said researcher Dr Jeffrey Ellenbogen, from Harvard Medical School.
These episodic patterns have been best studied in relation to sleep neurophysiology and include sleep spindles
, the so-called 'up-down' state of slow sleep rhythms and K-complexes.
Stage Description Duration W Wakefulness ~16 hours N1 Somnolence; "drowsy," easily awakened 1-5% N2 Asleep -50% N3 Slow Wave Sleep ~7% (SWS) Transition to deep sleep N4 Slow Wave Sleep ~20-25% (SWS) Deep sleep REM1-4 Rapid Eye Movement ~20-25% Stage EEG Brainwave pattern Events and abnormalities W Alpha waves Daytime consciousness N1 Theta waves Hypnogogic twitches, hallucinations N2 Slower waves, sleep spindles
, K-complexes Unconsciousness N3 <50% delta waves Melatonin peak, (SWS) night terrors, parasomnias N4 >50% delta waves Minimum core temperature, (SWS) rebounds after deprivation REM1-4 Rapid low-voltage EEG Dreaming, low muscle tone, rebounds after deprivation
In motor procedural tasks, an increase in the total number of stage II sleep spindles
, especially those in the last quarter of the night, may be seen for the groups that do well on posttraining retesting (Neuron 2002;35:205-11).
While you sleep, your brain stores new information into long-term memory via sleep spindles
(these are one- to two-second bursts of brain activity) associated with dreaming.
This change consists of an increase in sleep spindles
, resulting in faster sleep onset times and improved sleep maintenance.
Earlier research found a correlation between sleep spindles
- bursts of brain activity that last for a second or less during a specific stage of sleep - and consolidation of memories that depend on the hippocampus.
The rocking bed also had a lasting effect on brain activity, increasing slow oscillations and bursts of activity known as sleep spindles
We found that by measuring brain waves during sleep, we could learn a lot about how well a person's brain can block the negative effects of sounds; the more sleep spindles
your brain produces, the more likely you'll stay asleep, even when confronted with noise," said Jeffrey Ellenbogen of Harvard Medical School.