Sleep Science Podcast

Today's episode is a little bit different. We're marking the end of our first season by roping in the rest of the NaPS lab to answer listeners' sleep-related questions. Thanks to everyone who sent questions in!


List of questions:

Why do we use the term ‘sleeping like a baby’ when babies don’t, in fact, sleep?
- From Jaime Jenkins

How do hormones affect sleep?
- From Beth Lee

Why do some people talk in their sleep?
– From Christopher Reynolds

Can meditation before bed help you have deeper sleep?
- From Lauren Finaldi

Why do we need to cycle through different sleep states multiple times per night i.e why isn’t it half the night slow wave sleep and half the night of REM sleep?
– from Laura Bojarskaite

How come we remember dreams some nights and other nights nothing at all?
- From Suzie Saad

Is an eye mask effective for better sleep?
- From Lauren Finaldi

What exactly is happening during sleep paralysis and why does this happen sometimes?
- From Brittany McCabe

Do animals dream?
- From Veronica Campe

Are all of your senses still activated in sleep?
- From Naasiha Kolia

Can you fall asleep faster when you listen to white noise before bed?
- From John Nicol

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

Have you ever wished you could control your dreams? In this episode we learn about new approaches letting people do exactly that. We also delve into important benefits lucid dreaming could have, such as helping reduce nightmares or helping process traumatic memories. In addition, we explore how lucid dreams provide a window into understanding consciousness and people's inner worlds, and touch on the symbolism often found in dreams.

This episode was produced by:  Dominic Carr

If you'd like to find out more about the guests featured in this episode or want to read up on their lucid dream induction study feel free to follow the links below:

• Michelle Carr
• Karen Konkoly 
• Lucid dreaming induction study 

Glossary of terms used in the episode:

Confabulation = mistaken or unintentionally fabricated memories.

Dream sign =  something you notice in a dream that helps you realize that you're dreaming.

Dream theme = dreams tend to fall into common themes, such as dreams about being chased,  flying,  or getting lost somewhere.

Dream work = discussing your dream and perhaps re-imagining a more positive ending.

Entrainment = when your brainwaves become synchronized to another rhythmic stimulus.

EOG = electrodes placed near the eyes that detect eye movements.

Intention setting = setting an objective to fulfill while dreaming, such as asking  a dream character a specific question.

Prospective memory = remembering you need to do something in the future.

Reality checking = asking yourself if you could be dreaming.

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we talk to Dr Daniel Bendor from University College London. Daniel's work focuses on rodent studies of place cells in the hippocampus. 

We discuss the phenomena of memory replay in which place cell activity mimics  patterns of activity that occurred while the rodent was performing a task in wake.  We also discuss how this process can be manipulated using targeted memory reactivation (TMR). 

From this we discuss how the TMR instead of triggering a reactivation of a memory could instead be biasing the brain to replay the memory which is cued. 

We go on to talk about the relationship between the cortex and hippocampus and discuss theories on the hippocampus training the cortex in putting together components  of memories and how this dialogue may take place. 

Throughout the episode, we discuss rodents as sleep models and the positives and limitations of using them compared to human/primate models.

Finally, we discuss links between TMR and brain washing and the possible worries this may cause. 

If you'd like to find out more about Daniel's work you can find a link to his university research profile.  Some key studies referenced in this episode below:

• Replay and TMR: https://www.sciencedirect.com/science/article/pii/S0960982219310358
• Enhance, Delete and Incept: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4058530/
• Biasing hippocampal replay: https://pubmed.ncbi.nlm.nih.gov/22941111/
• Mapping the future: https://www.sciencedirect.com/science/article/abs/pii/S1364661316000218

Glossary of terms from the podcast

Targeted Memory Reactivation (TMR) = the process of pairing sensory cues with learnt information to improve memory consolidation during sleep

Place cells = neurons in the hippocampus which fire when an animal is in a specific location, known as a place field.

Ground Truth = is empirical evidence or information collected from direct observation

Pattern Separation  = The differentiation of similar, overlapping neuronal activity into distinct, non-overlapping groups

Sharp Wave Ripples = waves seen in the hippocampus during sleep and rest

Engram =  a neuronal representation for the existence of  a memory

Type 1 error = known as a false positive , when a true hypothesis is rejected

Type 2 error = known as a false negative, when a false hypothesis is accepted

Spike-timing Dependent Plasticity  = the effect where the timing of neuronal spikes modifies a synapse in terms of magnitude and direction

Optogenetics = the process of modifying neurons so they can be activated and controlled directly by light



If you have any questions about this episode, any of other episodes or the topics we discuss, please let us know via our email [email protected] or contact us through our social media @SleepSciencePodcast


Produced by Sophie Smith 

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we talk to Professor Björn Rasch about the pioneering of a process called Targeted Memory Reactivation (TMR).

TMR is a tool which can be used to selectively consolidate learnt material during sleep by pairing it with sensory stimuli such as odours or sounds during learning.  This process can be used to manipulate memories during sleep and improve memory consolidation. We also discuss how TMR can interfere with consolidation and consider the pros and cons of this technique as a tool for memory manipulation.

We then go on to discuss some of Björn's other work, including how sleep can amplify the positive impacts of therapy, and how this process can be used help overcome problems like arachnophobia.

If you'd like to find out more about Björn's work you can find a link to his research page and to some key studies referenced in this episode below:

https://www3.unifr.ch/psycho/en/research/biopsy/

 Here are links to some of the studies mentioned in the podcast:

         o Targeted Memory Reactivation
         o Labile or Stable
         o Auditory Feedback and Memory cueing
         o Arachnophobia

         
Glossary of terms from the podcast

Labile  =  unstable or easy to change

Pattern Separation  = The differentiation of similar, overlapping neuronal activity into distinct, non-overlapping groups

Generalisation  = grouping of similar overlapping information to a general output

Engram = a neuronal representation for the existence of  a memory

Salience = of importance

Closed Loop Auditory Stimulation  (CLAS)  = the method of using click sounds during sleep to enhance slow oscillations



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Episode produced by Penny Lewis and Sophie Smith 

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode we take a neuroethological approach to sleep, and discover why songbirds are such a good model system for studying sleep's role in learning. These include advantages like songbirds' sleep-wake patterns and sleep architecture being more similar to human's than rodents', the fact that songbirds are strongly motivated to learn their songs, which can then be easily assessed for accuracy, and the observation that population-level neuronal replay in the song system is often very easy to identify, since patterns of neural firing during replay can actually sound like the songs.  We're led through this fascinating topic by Professor Dan Margoliash and Dr Tim Brawn, whose work in Zebrafinches and Starlings has revealed valuable insights into perceptual, declarative and procedural learning, as well as how reconsolidation works, and into why interference learning may sometimes even be useful.

If you'd like to find out more about their work you can find links to their research pages and to some key studies referenced in the episode below:

Here are the websites for Professor Dan Margoliash and Dr. Tim Brawn

Here are links to some of the studies mentioned in the podcast:
        o Reconsolidation & interference
        o Perceptual & interference learning
        o Tutor song selective neurons
        o Finger-tapping
        o Sleep for perceptual learning
        o Sensorimotor integration

Glossary of terms from the podcast

Finger-tapping task = explicitly learning a numeric sequence and typing it as fast and accurately as possible with your non-dominant hand. For instance, you might be asked to type the sequence 4-1-3-2-4 repeatedly while the sequence is displayed on a screen. This primarily tests procedural learning rather than working memory.

Interference = one memory hindering the retrieval of another, e.g. because both memories have overlapping retrieval cues.

Neuronal bursting = periods of multiple action potentials clustered together, which are then followed by extended silent periods.

Reconsolidation = refers to how recalling memories returns them to a labile state, meaning they then need to be re-stabilized to commit them back to long term memory. New learning that takes place before this happens can be used to update the original memory.

Song motif = the individual phrases that make up the song. They are themselves constructed from syllables.

Song stereotypy = refers to a bird's song being repeated with great consistency once learned.

Song system = the discrete set of brain areas that controls song learning and production.

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

We humans have long wondered if it is possible to learn while we sleep but, experimental findings on this have often been disappointing. You will now be happy to learn that the tide has turned in this respect, since we now have firm proof that it IS indeed possible to learn new information while you sleep.  However - the information your brain can pick up in this manner might not exactly go as easy as you hope it would. 

In this episode, we interviewed Dr. Anat Arzi and Dr. Thomas Andrillon two of the first researchers to incontrovertibly demonstrate that the human brain can learn during sleep. They tell us about the similarities and the differences between their results and we speculate about the possible reasons behind the disparities.

Produced by:  Eniko Simo

See the web profiles of Anat and Thomas:

Publications discussed in the program:

o   Humans can learn new information during sleep; Arzi, A. et. al. Nat. Neuroscie. 2012.
o   Olfactory aversive conditioning during sleep reduces cigarette-smoking behavior; Arzi A. et. al. Journal of Neuroscience 2014.
o   Formation and suppression of acoustic memories during human sleep.  Andrillon, T. et. al. Nature Communications, 2017.
o   Sleepers Selectively Suppress Informative Inputs during Rapid Eye Movements.  Andrillon, T. et. al. Current Biology, 2020.

Glossary:

Associative learning = a learning process in which a new response becomes associated with a particular stimulus.

Perceptual learning = repeated exposure enhances the ability to discriminate between two (or more) otherwise confusable stimuli.

Aversive learning = a form of conditioning where an aversion is created toward a targeted behaviour or item by pairing it with an unpleasant stimulus. 

Thalamic gate = the thalamus filters sensory information. All sensory inputs go through the thalamus except for olfaction (sense of smell). 

Peaks & Troughs = the highest and lowest points of oscillations. In this case, of the brain waves during Slow Wave Sleep. 

Tag = a marker that can be attached to some kind of information indicating that it has a special status (e.g. it may be more strongly replayed or consolidated) 

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode we examine how sleep differs between species to get some clues about  what sleep actually is as a phenomenon. How have marine animals solved the problem of sleeping when they regularly need to come up for air? And how do amphibians adapt their sleep architecture from life at sea to life on the land? What can mice running on their wheels tell us about what may be happening in our brains when we're performing tasks on autopilot? How do states like hibernation or torpor relate to sleep? Are sleep stages really as homogeneous as we like to think? Might even plants show some ability to learn connected to their circadian rhythms? We will find out the answers to all of these questions and more in conversation with Dr Vlad Vyazovskiy.

If you'd like to find out more about Dr Vyazovskiy's work you can find his Oxford University profile and a link to Oxford's Sleep & Circadian Neuroscience Institute below.

Vlad recommends the following articles if you'd like to learn more about hibernation, wheel running, or local sleep:

https://theconversation.com/could-humans-hibernate-54519

https://theconversation.com/why-running-could-keep-you-awake-at-night-69320

https://www.scientificamerican.com/article/sleeping-while-awake/

Glossary
Crepuscular = active during twilight
Diurnal = Active during the day
Down state = silent/non-firing period of a neuron
Homeothermic = animals that maintain a stable body temperature
LTP = Long Term Potentiation, a long-lasting strengthening of synaptic connections
Photoperiod = day length
Sleep homeostasis = the pressure to sleep that builds up with time awake. It is linked to the accumulation of adenosine as we break down ATP to provide energy for various activities.

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode we ask Gina Poe, a sleep scientist from UCLA, about her seminal work on both REM and non-REM sleep. We talk about the role of memory replay in REM, how to measure such replay in rats, as well as the ways in which REM impacts upon emotional representations, and may even help us to combat post traumatic stress disorder (PTSD).  We also discuss the importance of sleep spindles for updating conceptual knowledge.  Finally, we describe Professor Poe's ground-breaking findings on local sleep and how these may change the face of sleep research in the future.

Produced by: Eniko Simo

See Professor Poe's faculty profile:
https://www.ibp.ucla.edu/faculty/gina-poe/

Find the research papers mentioned in this episode here:
https://academic.oup.com/sleep/article/39/12/2201/2706367
https://www.sciencedirect.com/science/article/pii/S096098221831279X?via%3Dihub
https://link.springer.com/article/10.1007/s00221-014-3890-4
https://www.liebertpub.com/doi/10.1089/jwh.2020.8332


Glossary:
EEG = Electroencephalography is an electrophysiological monitoring method for non-invasively recording the electrical activity of the brain via electrodes placed on the scalp.

Heterosynaptic plasticity = when synaptic pathways that were not directly stimulated themselves undergo changes (synaptic plasticity) as a result of neighbouring synapses being stimulated. Often this means that as one pathway is used and strengthened, an unused neighbouring pathway gets weakened.

PTSD = Post-traumatic stress disorder is a mental health condition that's triggered by a terrifying event. Symptoms may include flashbacks, nightmares, and severe anxiety, as well as uncontrollable thoughts about the event.

Schema = a cognitive framework or concept that helps organize and interpret information.

Spindle = distinct brain waves with frequency 11-16 Hz (measured with EEG).

Theta = 4-8 Hz brainwave frequencies.

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode we look back on the beliefs and practices people had around sleep in the 16th-18th centuries. We learn about why sleep was thought so important for health, how various habits and superstitions arose around sleep often rooted in medicine or religion, and how the bedroom became a symbol of status and power. We also cover how the electrification of society radically changed our relationship with sleep.

Produced by:  Dominic Carr

If you'd like to learn more about Professor Sasha Handley's work on the history of sleep, or are interested in checking out her book, feel free to follow the links below:

Professor Handley's researcher profile: https://www.research.manchester.ac.uk/portal/sasha.handley.html

Goodreads review: https://www.goodreads.com/book/show/28819134-sleep-in-early-modern-england

Amazon link: https://www.amazon.co.uk/Sleep-Early-Modern-England-Handley/dp/0300220391


More on the How We Used to Sleep Project: http://www.historiesofsleep.com/





This recording is property of the sleep science podcast and not for resale

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

In this episode, we speak with Professor Bob Stickgold, one of the most prominent researchers in the field of sleep science. Bob tells us about the early days of sleep research and how he and other scientists struggled to convince the world that sleep really is important for memory.   He also talks about methodological subtleties to investigate the role of sleep on cognitive functions, the purpose of dreaming, and offline default mode processing in general, and what he sees as the most interesting future research directions of sleep.

Produced by:  Eniko Simo

See Professor Stickgold's faculty profile here.  His new book 'When Brains Dream' is here.

If you'd like to read more about the topics Professor Stickgold mentioned you can find some of his related publications here:

1) Karni and Sagi's 1994 Science paper on how sleep boosts visual discrimination
2) Bob Stickgold's 2000 Nature Neuroscience paper on sleep and the visual discrimination task
3) Matt Walker's 2000 Neuron paper on how sleep boosts performance on the finger tapping task
4) a sample of Erin Wamsley's work on dreams
5) a 2000 review, in Science, of Bob's early thoughts on sleep, memory, and dreams.

Glossary:
p-value = a statistical measure to test if the findings of an experiment are significant. 0.01 means a robust paradigm. 





This recording is property of the sleep science podcast and not for resale

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.