Sleep and Cognition Flashcards
Sleep deprivation
Yoo et al (2007)
- sleep deprived when encoding images
- control group sleep normally before encoding images
- ps are in firm when encoding images
- lack of sleep prior to encoding compromises learning as a result of hippocampus not being able to encode new information properly
- sleep prepares brain for new learning.
Sleep architecture
- There are 4 stages of sleep
- Non rapid eye movement (REM) dominates early In the night, REM late at night.
- Stages 3 and 4 are slow wave sleep
Sleep and Motor Learning
Walker et al (2002)
- sequential finger tapping task on non dominant hand.
- 1st group stay awake after learning sequence
- 2nd group sleep after learning sequence
- stage 2 of sleep is critical for learning new motor skills
- improved more at task after sleep.
Sleep and Problem solving
Monaghan et al (2015)
- source problem completed at 9am and then target problem completed
- source problem completed at 9pm, sleeping then target problem completed
source problem could be - general attacking a fortress with mines on the road
target problem - how to target a stomach tumour with a ray that destroys healthy tissue
- solution accuracy was correlated with sleep duration. More sleep = more accurate target problem solutions.
- sleep facilitates transfer of old solutions to new problems
Sleep and Insight
Wagner et al (2004)
- Number reduction task
- Insight is the hidden resolution to problem which is acquired in sudden insight.
- wanted to see if sleep helps you to arrive at the insight
- 3 groups, sleep, wake night and wake day.
- the largest number of participants to gain insight was sleep group
- sleep facilitated calculations in the non solvers in the sleep group
- sleep had no impact on the reaction time of solvers
Sleep and False Memories
Payne et al (2009)
- Two groups, sleep and wake
- memorise 12 DRM lists, then sleep or stay awake.
- control groups did it at different points of day to ensure time of day doesn’t influence results
- sleeping brain continues to process new memories
- sleep group memorised more words than wake group
Mechanisms of consolidation
Salient & Walker (2012)
3 systems A, B, C
A, Hippocampus encodes new information and integrates it in distributed cortical networks
B, Hippocampal information repeatedly reactivated during sleep, strengthens cortical connections over time.
C, Reactivation over time integrates new memories with cortical memories
Reactivation during sleep
Rasch et al (2007)
- learning object locations
- memories were cued during sleep using the same order experienced when learning (rose)
- re exposure during slow wave sleep (SWS), improved hippocampal dependent memories
- order was ineffective during rapid eye movement sleep.
Dreaming and Memory
Hall (1972)
- people tend to dream about their waking experience
- Hall wrote accurate profiles and histories of psychiatric patients by reading their dream reports
- dreams incorporate waking experiences with recent and old memories
Dreaming and Memory
(Spano et al, 2020)
- Damage to hippocampus and dreaming
- 4 patients with selective bilateral hippocampal damage
- Not detailed dreams compared to controls
- Dream less frequently than controls
Dreaming and Memory
(Wamsley et al, 2010)
- train on a maze navigation task.
- either take a nap or stay awake
- asked 3 times what they were dreaming about
- re test on maze task later in the day
- sleep group improved during nap wake group didn’t
- people who reported dreaming about task, improved at task
- those who don’t dream about task didn’t improve
- dreams don’t. just reflect wake experiences, they include existing semantic memories as well.
Dreaming and Memory
(Kumral et al)
- ps listened to 1/4 audiobooks when calling asleep.
- reported dreams after 90 minutes of sleep
- EEG records throughout
- from dream reports the audiobook could be predicted
- could also predict from brain activity during REM as well.
- however, couldn’t predict this from SWS, suggests memory reactivation happen during REM too.
- participants who remembered more REM beta activity remembered more about the book after.
Replay, (day)Dreaming and Memory
(Gupta et al, 2010)
- rats learn to find food in a maze
- at wakeful rest, rat hippocampus replays the sequence
- the rats sometimes replay it identically and backwards
- rats hippocampus also workout short cut sequences when resting
- brain activation at rest involves exploration of non experiences sequences but possible events.
