9-10. functions of sleep

Question 1

what is the role of the hippocampus in memory consolidation

Answer 1

transfer short term memory into long term memory, creates representation of a memory, doesn’t store memory, it binds cortical traces together so that they remain solid over time.

Question 2

study where participants slept after training vs after retest: which one improved more after sleep?

Answer 2

Both group improved hugely after having slept.

It’s not just time, it is about sleep.

Question 3

study where they had group 1 that slept right before exercise and group 2 that was sleep deprived, do they remember all stimulus types the same way?

Answer 3

For negative stimulis, not significant difference between groups. Basic evolutionary need. Danger. Negative bias. Negative stimulis will be learnt anyway.

Positive stimulus were forgotten by sleep deprived group

Question 4

sequential hypothesis of sleep-dependent memory consolidation

Answer 4

memory consolidation is best supported when there is a sequential, cyclical progression through different sleep stages: distinct stages of sleep to contribute to memory processing in complementary ways

Question 5

active system consolidation

Answer 5

The idea is: in sleep memories get organized not simply passive but rather memories are changed, active processes.

Question 6

what is the dominating theory right now about how the brain reorganizes itself during sleep.

Answer 6

active systems consolidation

Question 7

active systems consolidation

Answer 7

Hippocampus: binds cortical representation together to form a memory. Doesn’t contain a memory. Replaying sequences it learnt during the day. See number 1. in the image. After doesn’t need hippocampus anymore to activate memory. Not all memories are hippocampus dependent (more implicit things, preferences for people even though don’t know who they are. So during the night get this process through slow waves, spindles, hippocampal ripples, memories are replayed. Still mysterious, don’t know everything. Happens actively in sleep.

Question 8

which neural oscillation predicts learning in all stages

Answer 8

delta waves

Question 9

selective item consolidation

Answer 9

You lived two experiences: one is remembered, one is not.

Question 10

item integration

Answer 10

You have already know these four facts and then you learn a new thing that is related, after a couple mornings, you will remember them as being integrated. You won’t remembered them seperately.

Question 11

Basic model of sleep dependent memory consolidation.

Answer 11

1. You learn a bunch of stuff. Learn three things. Hippocampus is creating a connection with the neocortex. Stores there for the time being as you are awake. Directionality from neocortex to hippocampus.
2. Go to bed. Saturated brain. When you go to sleep:
   a. synaptic homeostasis (liberating extra cellular space, pruning out unnecessary connections)
   b. active systems consolidation (replaying connections, hippocampus talks upwards to the neocortex. Reinforcing this memory trace as you are sleeping)
3. In the morning your hippocampus doesn’t need to communicate to your neocortex anymore, neocortex has all of those things already there.

Question 12

sleep to forget sleep to remember theory

Answer 12

• sleep reduces the affective blanket surrounding experience (attenuation of amygdala response)
• emotion tags some memories as more relevant for consolidation
• rem sleep: consolidation and integration of emotional memory while decoupling that memory from emotion, thus reducing further anxiety when reactivated

Question 13

if you don’t sleep enough you will be jumpy. why?

Answer 13

amydala activation is of much higher amplitude and intensity (not so well attenuated by prefrontal cortex)

Question 14

targeted memory reactivation

Answer 14

technique that involves reactivating specific memories during sleep to enhance their consolidation

sensory cues (such as sounds or odors associated with a learned experience) are presented during sleep, usually in slow-wave sleep (SWS), to trigger the brain to replay the associated memory

Question 15

Big study where they had people do this memory game. Exposed to an odor.
They would do a learning session before they would go to sleep.
And then during sleep exposed to the odor as there’re asleep. what was the winning condition?

Answer 15

those who were exposed to the odor during learning and in slow wave sleep