Cog & Bio Sleep And Memory

Question 1

What does our memory allow us to do?

Answer 1

Learn from past events and adapt to new situations
Solve problems and make good decisions
Maintain relationships
Have a sense of self and identity

Question 2

What is encode?

Answer 2

Activity has to happen to actually encode it and then be able to recall it

Question 3

What is retrieval?

Answer 3

Have to access memories to be able to retrieve them

Question 4

What is used to measure sleep?

Answer 4

Polysomnography
Means ‘many sleep write’ = ‘lots of sleep recordings’
Self reported

Question 5

What 3 methods does polysomnography consist of?

Answer 5

Electroencephalography (EEG, brain activity)
Electrooculography (EOG, eye movements)
Electromyography (EMG, muscle activity)

Question 6

What is unihemispheric sleep?

Answer 6

Sleep with half brain at a time - one side of brain is asleep and other side of brain is awake

Question 7

What stage is the deepest stage of sleep?

Answer 7

Stage 3 - brain slows down

Question 8

When does sleep walking occur?

Answer 8

During non rem sleep

Question 9

What are the 2 types of sleep?

Answer 9

Rapid eye movement (REM)
Non-rapid eye movement (NREM)

Question 10

How can NREM be subdivided?

Answer 10

1. NREM (N1)
2. NREM (N2)
3. NREM (N3 - or slow wave sleep)

Question 11

How long is each cycle?

Answer 11

90 mins

Question 12

When does REM happen?

Answer 12

After N3

There’s a shift in ratio of rem and non rem throughout the night

Question 13

Wakefulness:

Answer 13

EEG - low-amplitude mixed frequency, alpha rhythm (8-13hz) in occipital channel
EOG - eye blinks (0.5-2hz) - reading eye movements
EMG - higher than sleep

Question 14

What is frequency?

Answer 14

How fast brain wave goes through full cycle

Question 15

What is amplitude?

Answer 15

How big the waveform is

Question 16

Stage 1 sleep:

Answer 16

EEG - low-amplitude mixed frequency, slower than wakefulness (4-7hz)
EOG - slow, rolling eye movements
EMG - lower than wakefulness but higher than rem sleep

Question 17

Sleep stage N2:

Answer 17

EEG - K-complex (negative deflection followed by positive component) - sleep spindles (12-15hz waveform; 0.5-2sec)
EOG - unremarkable
EMG - lower than wakefulness but higher than rem sleep

Question 18

Sleep stage N3: slow wave sleep

Answer 18

EEG - slow wave activity (0.5-2hz), peak to peak amplitude >75
EOG - unremarkable
EMG - lower than wakefulness but higher than rem sleep
Big amplitude, low frequency

Question 19

Sleep stage REM:

Answer 19

• EEG - low amplitude mixed frequency (similar to wakefulness) - no slow oscillations, sleep spindles, or K-complexes
  EOG - rapid eye movements
  EMG - lower than wakefulness and NREM sleep

Question 20

What happens in our brains when we sleep?

Answer 20

Sleep is associated with distinct patterns of electrophysiological brain activity

Question 21

What happened in the first sleep and memory study?

Answer 21

People who slept recalled more than 5x the nonsense syllables compared to people who didn’t sleep - sleep plays an active role in strengthening recently acquired memories

Question 22

What role does the hippocampus play?

Answer 22

Hippocampus picks up memories quick, memory systems need to interact with each other - new memories are encoded in the hippocampus and the neocortex

Question 23

In order to retrieve memories …

Answer 23

The hippocampus has to bind together all the different aspects of the memory

Question 24

What happens when sleep spindles and sleep oscillations coordinate?

Answer 24

Strengthens the different parts of the neocortex - hippocampus is no longer needed as connections with the neocortex has strengthened - neocortex can retrieve the memories on its own now

Question 25

Slow oscillations facilitate memory consolidation : What does TDCS do?

Answer 25

Apply weak electrical currents on the brain to manipulate brain activity - manipulates frequency of brain activity between 2 electrodes

Question 26

Slow oscillations facilitate memory consolidation :

Answer 26

Those who slept in the lab had electrodes put on their brain to manipulate brain and then in the morning the participants got tested on declarative and non-declarative memory tests - those who had stimulation applied during sleep performed better on declarative test compared to participants who didn’t have stimulation applied Shows slow oscillations actively drive memory consolidation

Question 27

What do slow oscillations facilitate?

Answer 27

The transfer of info from shorter term shore in the hippocampus to the long term store

Question 28

Non-declarative tasks don’t require what?

Answer 28

The hippocampus

Question 29

Sleep facilitates memory redistribution :

Answer 29

Longer SWS direction was associated with superior recognition per formation for remote (but not recent) pictures on days 1, 2 and 30 - among participants who had a nap Longer SWS duration was associated with reduced hippocampal engagement for correctly-recognised remote vs recent pictures

Question 30

Sleep associated memory replay drives consolidation :

Answer 30

Participants saw pictures with their cooccurring sounds, then had a nap and half of the sounds were played to them in their sleep - when waking up and performing the task, participants would perform better in the images where the sounds were represented to them in their sleep Memory replay during sleep drives overnight memory strengthening

Question 31

How do we transform everyday experiences into enduring memories?

Answer 31

New memories are initially weak and susceptible to interference, over time, new memories are strengthened and integrated into excoriating knowledge structures, this consolidation process is facilitated by brain activity that occurs during sleep

Question 32

What role does sleep deprivation play?

Answer 32

In a study, people who slept recalled more than 75% of words - sleep deprivation only prevents us from consolidating memories already acquired but also slows down new learning

Question 33

Slow oscillations facilitate post-sleep encoding :

Answer 33

Stimulation improved memory for pictures and word pairs and word list - hippocampus dependent memories benefitted from the stimulation Procedural learning task, which isn’t hippocampus dependent, did not get improved through stimulation

Question 34

How do we encode new memories without overwriting existing ones?

Answer 34

The hippocampus is critically involved in memory encoding Sleep-associated memory consolidation redistributes new memories from the hippocampus (short-term store) to the neocortex (long term store) This redistribution may free up space for new learning