Week 6 RF-Sleep Flashcards
What 2 ways does sleep affect learning and memory?
- Lack of sleep impairs the ability to focus and learn effectively
- Sleep is necessary to consolidate a memory so that it can be recalled
in the future
How might sleep affect memory?
- Blood flow problems could hinder brain functioning
- Sleep-deprived mice have beta-amyloid plaques (clumps). Beta-amyloid
deposits are linked to a decline in memory and risk of dementia
Which 3 brain areas are important in the storage of memory?
- Hippocampus
- Amygdala
- Neocortex
What is the role of the hippocampus in memory?
Where episodic memories are formed and indexed for later access
What Case Study established the role of the hippocampus in memory?
Henry Molaison, 1953:
* Hippocampus surgically removed
- Only able to form episodic memories lasting a matter of minutes
- Unable to permanently store new information
- Could remember events that occurred before surgery
Conclusion:
* Hippocampus is the sight for laying down memory it is NOT the site of permanent storage
What did Rasch & Born (2013) find when investigating the role of the hippocampus in memory using fMRI?
- Sleep deprived students asked to view and remember images
- Performed as much as 40% worse on recall two days later
- Activity was significantly decreased in the hippocampus
- Analogous to a lesion on the hippocampus
- Memory impairment rather than concentration
- Memories ‘jammed’ in the hippocampus
What is the role of the Neocortex in memory?
- Largest part of the cerebral cortex
- Involved in higher functions
- Important in long term storage of memory
- Memories transferred from hippocampus to neocortex during sleep
- Deep sleep, slow wave and REM sleep
What is the role of the Amygdala in memory?
- Attaches emotional significance to memories
- Strong emotions are difficult to forget
- Interaction between hippocampus, neocortex and amygdala determine
stability of a memory - Forms new memories related to fear
- Fearful memories formed after only a few repetitions
- Relevant to PTSD
What are some open questions regarding the underlying neural mechanisms of
sleep?
1- How NREM and REM sleep influence learning and memory?
2- Is learning acquired before sleep enhanced or stabilized after sleep, or does sleep protect what was learned from being “overwritten” by learning something new?
3- is the facilitation of learning learning-specific or learning-independent?
What is the Plasticity of Memory?
- The brain never stops changing and adjusting
- Plasticity = capacity for change
- Change in internal structure of neurons
- Increase in number of synapses between neurons
What were the findings of Tamaki et al’s (2020) study?
1- In NREM sleep there is a release of glutamate, which was called an excitatory shift
2- In REM sleep there was a release of GABA which was called and inhibitory shift
3- Individuals with more NREM and excitatory shift, did better, the bigger the shift the bigger the improvement
4- Participants that had more REM sleep had an inhibitory shift which seemed to be less associated to getting better on the task
What were the methods of Tamaki et al’s (2020) study?
-In this study they trained participants in a visual learning task
-Then they had a 90-minute nap in an MRI and used a technique known as Magnetic Resonance Spectroscopy which picks up neurotransmitters.
-They measured GABA and glutamate in visual areas while they slept and also had EEG
-Participants were woken up and tested on task again
What was Tamaki et al’s (2020) Second Part of the Study?
Same participants learning a different task that interfered with the original task and tested them in the original task e.g., learnt french then spanish then tested them on their french
What were the findings and interpretation of Tamaki et al’s (2020) Second Part of the Study?
-The participants that did better were the ones that had some NREM but also the inhibitory REM
-During NREM the excitatory shift, or increase in glutamate enhances learning through brain plasticity, the brain forms new connections
-The inhibitory shift (release of GABA) during REM stabilises the newly formed connections
What is the art of napping and dreaming? (Wamsley et al., 2010)
- Napping can be helpful for improving memory
- Dreaming about a task can boost memory for that task
Some considerations:
* Limit napping to short bursts
* Target to natural dips in alertness
* Long naps may interfere with a normal
night’s sleep
