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Podcast Episode 063: Can you listen while you sleep?

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Can you listen while you sleep? Why do we wake up when someone calls our name? And what exactly is the cocktail party problem?

In this episode, Oscar speaks with Dr Thomas Andrillon about listening and sleep. Thomas is a research fellow in Psychology at Monash University. He’s an expert on the brain during sleep, day dreaming and mind-wandering.

Hear about what the brain can process while we sleep, and what it can teach us for our waking hours. Learn how the brain can listen to multiple things at once, and switch our attention between them when it matters.

Learn Thomas’s tips to remove distractions, before they even become distracting! Finally, can we make decisions, or even learn while we sleep? Tune in to find out.

Transcript

Podcast Episode 063: Can you listen while you sleep?

Thomas Andrillon:

What this research means is that it’s not only during sleep people are hearing, so there are sensitive to sounds, but they can process these sounds meaningfully so they can recognise it’s a word, for example, they can recognise the category of these words. So a semantic category, whether it’s an animal or an object, and then they can map this content with a specific action responding right or left. So it’s a very, very powerful result because it’s really show this active listening during sleep. So not only a passive reaction to sounds, but the processing of that sounds in a meaningful way.

Oscar Trimboli:

Deep Listening: Impact Beyond Words. I’m Oscar Trimboli and this is the Apple award-winning podcast, Deep Listening. Designed to move you from an unconscious and distracted listener, to a deep and impactful listener. Did you know you spend 55% of your day listening? Yet only 2% of us have had any training in how to listen. Frustration, misunderstanding, wasted time and opportunity, along with creating poor relationships are just some of the costs of not listening. Each episode of the series is designed to provide you with practical, actionable, and impactful tips to move you through the five levels of listening. I invite you to visit oscartrimboli.com/facebook to learn more about the five levels of listening and how to learn from others who are listening better to help make you a deeper and impactful listener.

Oscar Trimboli:

Have you ever wondered what your brain and mind is doing while you sleep? Have you ever wondered, can you hear while you sleep? Imagine it’s after lunch and you’re feeling a little bit sleepy. Is it possible to listen to someone even if you’re asleep then? In this episode of Deep Listening, we speak to Dr. [Thomas Andrillon 00:02:13], a world expert in the field of listening while you sleep. What an amazing field to be able to say that you research in.

Oscar Trimboli:

This episode helps me to understand the why attention is focused and understand the immense power of the brain to parallel huge amounts of various information when it comes to dealing with sound. Dr. Thomas has had a long-lasting fascination with how the brain works and how thoughts emerge from such a tiny part of the human body. I was lucky enough to explore with him the question that I’m often asked, “Is it possible to listen at all five levels of listening simultaneously?” Listen out for the story about how mothers of newly born children can distinguish the cries of just their child in a hospital ward from all the other crying babies while they’re asleep. This episode has a wide range of implications for listening while you sleep, but we unpick so much more particularly as it relates to listening while you’re awake. Let’s listen to Dr. Thomas.

Oscar Trimboli:

What frustrates you when others don’t listen to you?

Thomas Andrillon:

I’m easily frustrated actually in this kind of situations, but I think the most frustrating part, I will say, is when I have the feeling that the people don’t listen, not because they are not interested in what I’m saying, but it’s more when they are not listening because they think that what I will say it is not relevant or will not make them change their point of view. That I think is perhaps the most frustrating thing both in personal or professional life. When you have a message and you figure out that the person in front of you has already taken the [inaudible 00:04:19] that what you are going to say won’t change a bit what they think.

Oscar Trimboli:

How many languages do you speak?

Thomas Andrillon:

So my mother tongue is French. I think I speak decent English but that we’ll see a throughout this podcast. I also speak Italian because my wife is Italian and a bit of Spanish.

Oscar Trimboli:

Do you think that being able to speak multiple languages helps you to listen differently?

Thomas Andrillon:

Yes, that’s definitely, especially learning to speak other languages than my mother tongue that is French, it made me aware of the way people speak. Because there are things in your own language that you don’t necessarily pay attention to because your mother tongue is not questioned in a way. It’s a given. And I don’t think we analyse our mother tongue the way we might analyse other language that we acquired later in life.

Thomas:

So I see that, for example, with Italian, where I’m paying more attention. So in Italy, you have this richness in accents or way of speaking that is incredible with sometimes changes in the way people speak, where they live in cities that are only a few kilometres apart.

Thomas:

And knowing more about the Italian language and the Italian culture and becoming more and more aware of the importance of listening, not only to the content of what people say, but also the way they say it.

Thomas:

Also living in a new country like Australia, I’m also discovering that what I’m missing by not understanding all the nuances in accents or way of speaking. So I cannot place or understand the people I’m listening to the way I would in a country that will be more familiar to me. So I’m becoming more and more aware of all these levels of information that are hidden in the way people speak.

Oscar Trimboli:

I’m fascinated by Thomas’s point about multiple languages and how you listen. It reminds me of [John Corrigan 00:06:35] in episode 13 where he talks about how he moved from learning French and Spanish with great difficulty and then learning Italian with great ease. Let’s hear from John.

John:

So I did a short service commission in the parachute regiment in the UK, which was three years as a platoon commander. And then I thought, I’m not really using my brain enough. I want to use the mathematics I got and converted into something more useful. So I then worked as what’s called a wireline logging engineer, which is taking measurements in drilled oil and gas wells. And I did that work largely in South America and various places in Europe, ending up finally in Italy.

John:

And in fact, this is one of the places where my thoughts about listening began to emerge in that at school I did everything I was told to do to learn French. I really, really wanted to learn French. Most people will be aware, very few people come out of school having spent say six years studying a language, being able to speak that language. So that was my issue, really wanted to learn French but essentially failed.

John:

In South America, I learned Spanish, but it was like banging my head against a brick wall. But there was no real alternative. I was an environment that was purely Spanish speaking. But then I moved to Italy and then I had a real confidence in my capacity to learn a language and so I just focused intently on listening to the Italians around me as they spoke.

John:

So after six months I could speak Italian fluently, but after 18 months I could have a conversation like this and people wouldn’t know that I wasn’t Italian. And I thought then how is it that I’d been able to learn fluently and effortlessly a language, when at school I did everything I was supposed to do and I failed to do it. And the only difference was the difference in the way that I was listening and at the time it didn’t understand what the difference was, but I noted that that was that difference.

Oscar Trimboli:

I think Thomas and John make great points and it applies equally to multi-language speakers as well as people who only speak one language. And the point is simply this, are you listening for similarities? Or are you listening for differences in the dialogue from your own point of view?

Oscar Trimboli:

I think if you reflect on, “Am I for something that aligns to what I’m thinking?” Versus, “Am I listening for something that’s completely different from what I’m thinking about?” It will start to open up the difference between trying to explore and discover new ways of thinking or trying to stay in the same place. I think listening brings a joy that will open up more possibilities. And although it can be considered a blessing and a curse, I think on balance being able to speak multiple languages helps you as a listener to listen differently.

Oscar Trimboli:

What happens to the auditory part of the brain when you start to take notes?

Thomas:

It will deepened immensely on what is the person doing when taking notes? Because when taking notes you can do it in two ways. You can either take notes about what is being said as a form of keeping track. Like in lectures when you note what the professor is saying because you want a copy of this for the future. Or you can take notes about the ideas that are triggered by what the person is saying. For example, when attending a meeting where suddenly someone will say something and you will think about something else and you want to take that as a note. And I will say that if you write about what you are hearing, you’re actually doing a auditory motor loop. Where your auditory cortex will still encode and you will still pay attention of what’s being said because you just want to write that down.

Thomas:

But if it’s more taking notes about your own thoughts or your own stream of thoughts, then it can become quite difficult to still pay attention to what is being said because most likely you will have in parallel a form of inner speech so yourself following your own train of thoughts. And it is known that inner speech is actually recruiting, motor and auditory cortices, or the same regions that are involved in talking and listening are involved when we are talking to ourselves. And that will prevent paying attention to what is being said. It’s just like when several people are talking to each other, it’s difficult to follow multiple speakers at the same time.

Oscar Trimboli:

Thomas, in your current research, your understanding is the brain capable of listening while it’s asleep? Is it possible for the brain to listen while we’re sleeping?

Thomas:

Listening is not passive. It’s an active process of paying attention and trying to make sense of what you are hearing. And with my research, I’m really trying to make the point that this active processing of auditory information can be, to a certain extent, preserve even when we are sleeping. That is already a huge step forward.

Thomas:

The research was actually not only questioning our ability to listen during sleep, but also our ability to hear. So for decades sleep was described as a state of what’s called sensory decoupling. So the fact that you will be, in a way, isolated, or your brain will be isolated from the environment while sleeping. And the way this was to be implemented will be that auditory information, visual information, pretty much all form of sensory information will be blocked before even reaching the cortex. The parts of the brain processing this kind of information.

Thomas:

So idea was called a [inaudible 00:12:50] gating in reference to the fact that all these sensory modalities, before reaching our cortex, they have to transit through a brain region called the thalamus that is playing as a form of relay between our brain and the outside and this relay was thought to be close when we are sleeping.

Thomas:

So the conclusion of this models or interpretation of the data that was available at the time, that’s not only, we cannot listen during sleep, but we cannot hear neither. So the first research on this showed that actually the brain is hearing during sleep because this [inaudible 00:13:28] gating, this blockade of information during sleep, doesn’t seem to hold. Actually, we have evidence in humans, but also in animals by recording directly, what the neurons do in the brain during sleep. We have evidence that they are still sensitive to external information.

Thomas:

My colleague, [Yuval Nir 00:13:47], who is based in Israel, made this fantastic recording where he was playing a symphony, I think it was a Beethoven Symphony, to rats while they were steeping, and recording the auditory neurons of these rats while listening to this piece of music. And he could replay this piece of music through the activity of these neurons afterwards, because these neurons, they encode, what the rats is hearing. And even during steep, just by listening to the neuron, you can actually retrieve what they were hearing. And that is a strong demonstration that the brain is still sensitive, it’s still hearing what is going on in the outside.

Oscar Trimboli:

Thomas, this raises as a common question that I get asked about. What’s the difference between hearing and listening?

Thomas:

We were exactly interested in this. Is the brain sensitive during sleep to any form of sound? Or is it processing these sounds based on their meaning? Based on also their importance or relevance?

Thomas:

So there were anecdotal evidence suggesting it’s a case that relevance or importance matters. And the first results going in that sense came from awakening. So one of the crucial characteristic of sleep is that it’s transitory. So we don’t sleep forever. Sleep is not coma, it’s not anaesthesia. We can wake up at any moment. And sounds can trigger this awakening. But it appears that not all sounds are equivalent. So if for example you hear your own name during your sleep, the probability you will be awoken by your name is increased compared to another name Even if I acoustically speaking, so in terms of intensity of acoustic energy, everything is kept constant.

Thomas:

So the fact that what you are hearing has a personal relevance that can facilitate this emergence from sleep and this finding was used as a good argument to say that the brain is still sorting out the formation based on its meaning. So then it can be argued that names, especially or your own name, is quite peculiar. So maybe it’s a matter of your sensitivities. So you’re just more sensitive to [inaudible 00:16:19] but that’s a learned ability, that’s not something that your brain is really doing while sleeping and just it has learned to be sensitive to that particular sound while being awake.

Thomas:

So researchers are trying to disentangle these different things. So are we sensitive to things while we sleep because we’re just used to it or because really we’re processing their meaning? So a beautiful piece of research that has been made on this was actually studying a mother who just had a baby. So when they were sleeping in a clinic in the good old days where a young mother were kept in wards with several young mother and several babies, they looked at the ability for mothers to wake up when their own babies cry versus another baby.

Thomas:

And they showed that mother can actually do this. They will tend to wake up more for their own baby or their own baby’s cry versus another. And this is of particular interest because a baby cry first is it’s not something easy to recognise. It’s not like a name, it’s a cry. And the second thing is since this mother had given birth recently, this is not a noise they have been used to hear for years. So it’s a quite new information. It’s an information that is a hard to describe or to memorise. And yet the mothers had this sensitivity and acquired this sensitivity quite rapidly to very relevant, very important sound in their environment.

Thomas:

So in my work, what I was interested is trying to see what’s going on when sleep is preserved. So when I play a sound to a sleeper and the sleeper is not awake, is the brain still processing this information or you have to wake up to be able to process it? So the way we typically do that is that we invite people in our laboratory. So they would come to the lab and we’ll just have them installed in a comfortable chair. We would have asked them to sleep less than usual the night before, just to have them a bit more tired. And we’ll just put comfortably in a chair in a dark room. They will do what [inaudible 00:18:48] people do is they would just most of the time fall asleep. So what we did was while they were falling asleep and during their sleep we were playing sounds to them.

Thomas:

So the first experiment we did, for example, is participants receive list of words. So one word after the other and they had to determine whether the word they heard was referring to an animal like cat, dog, or an object like table, spoon. So what they had is they had response button in the hands and they had to press, for example, right when they were hearing an animal and left when they were hearing a name of object.

Thomas:

We wanted to see whether this kind of process can be maintained during sleep. To see whether it was maintained or not during sleep, we had a problem which is that sleeping people cannot respond so they cannot press the button. So how do we know that there are actually still classifying these words? So here is where the fact that they were giving right and left responses is important because when you’re preparing yourself to press a button on the right, you have a differences between the right and left part of the brain.

Thomas:

So the right hand is commanded by the left motor cortex. And when you prepare for right answer, your left motor cortex is getting activated. And if you record brain activity through an electroencephalograph, so if you recalled brain activity while people are awake, for example, you can see this change and this lateralization of the brain activity in preparation for a response.

Thomas:

So what we did was to look for the same pattern of brain activity while people were sleeping. And we were quite happy to see that in sleep, we were seeing things that are similar to wakefulness. So people were still preparing for the correct response while they were sleeping. [inaudible 00:20:44] these process were usually much slower. What this research means is that not only during sleep people are hearing, so they are sensitive to sounds, but they can process these sounds meaningfully. So they can recognise it’s a word, for example, they can recognise the category of these words.

Thomas:

So a semantic category, whether it’s an animal or an object. And then they can map this content with a specific action responding right or left. So it’s a very, very powerful result because it’s really show this active listening during sleep. So not only a passive reaction to sounds, but the processing of that sounds in a meaningful way. And passing this information that has been extracted to the sound, to other brain region will decide, for example, to prepare for a right or left answer.

Thomas:

So we call that result when we talk about this to a researcher or to the public, we say that, the sleeping brain can still decide, so we can still take information from the outside world and make a decision out of it. Although the decision here to be made is quite simplistic.

Thomas:

So in our latest study, we were interested in the process of selection. So when you’re exposed to different sources of information, how you select which source you want to pay attention to. And that, in auditory research, it’s called the cocktail party problem. So you can picture yourself in a party and there’s several people talking at the same time and it’s very easy for you to jump from one speaker to the other. And this can be done willfully. So you want for example, suddenly to listen to the person talking next to you and not in front of you. But sometimes our attention is catch, [inaudible 00:00:22:48]. So imagine that you’re in conversation, a potentially boring conversation, and suddenly someone, maybe across the room is pronouncing your name. So this can automatically attract your attention because there is a relevant piece of information that has been pronounced.

Thomas:

Even if you are not paying attention to this particular speaker, then your attention is attracted, which means that although we have the impression to be able to focus on only one speaker at a time, our brain can actually [inaudible 00:23:20] several speakers altogether and jump from one to the other. Because to be able to jump from one speaker to the other, you need to process at least minimally, the other speaker.

Thomas:

You are not aware of your environment when you’re sleeping. So we were interested in using this particular state to understand in that state of non-awareness whether the brain can still, select information and do this job of paying attention to someone and not the other. And what [inaudible 00:23:52] is that it’s still possible even when we’re sleeping. So when we’re sleeping we’re still able to separate sources and to focus on one versus the other. And that I think emphasise or stress what’s going on when we are awake, that is our brain without us knowing or without us realising, is constantly passing the information that is in our environment. And although we have this impression that we are limited that we can pay attention to only one speaker or to only one sound at a time, actually your brain is doing something much more complicated, following everything that is happening. So it will be able to suddenly change our focus of attention if needed.

Oscar Trimboli:

Although your research, Thomas, is about how we listen while we sleep, are there any implications or things we could learn from your research about how to listen when we’re awake?

Thomas:

I will say that one very broad but important implication of this research is about consciousness and the brain. In the auditory domain, it’s a bit like this. I mean we are conscious of the cherry in a way but not the cake. We are able to pay attention and to deep listen to a very limited amount of information, but we have access in the background, and without realising it, to a lot of information and a lot more than we would imagine.

Thomas:

And that, in neuroscience, has been the actually theorised that this is by design and this is actually important. That will be a combined by a world series of parallel processing that will try to monitor the rest. But to be able to deeply process one type of information, you will have to ignore all the rest. And conscious and unconscious processes in the brain will do the job of separating the jobs between conscious processes that are limited in the quantity of information they can handle, but do a very deep processing of that information, and unconscious processes that are more widespread that can take a lot of information then cannot process it deeply.

Oscar Trimboli:

Thomas, given how thorough your research is, are there any tips in there about how to stay focused while you’re listening?

Thomas:

If you want to maximise your ability to listen? I think it’s one important thing and what is demonstrated by this research on sleep, but all the research on the attention is there you can work on your environment to help yourself listening deeply to something. So once we know that all brains will maintain processes that we don’t control and that will be sensitive to any change in their environment, that is either irrelevant or simply unpredictable, you will tend to lose attention whenever these events occur. And that’s not necessarily something you can totally control. So by making that environment eventless or as predictable as possible, you will be able to make sure that your deep listening is not distracted by competitive processes over which you have more control.

Thomas:

Working or being in a quiet room, for example, is obviously quite important. Also putting yourself in a situation where you are not over-monitoring your environment. For example, when starting this podcast, I took your advice of putting may phone on the flight mode. And I thought about it actually, I could have put it on silent mode. I mean what’s the difference between silent mode and flight mode if I’m not looking at my cell phone. There is none.

Thomas:

And yet there is a fundamental difference that if phone [inaudible 00:28:08] in flight mode, I know it will not receive anything. While on the silent mode, it might receive something. I think paying more attention to my phone if it’s in silent mode because I know that at some point it could have received a message or a call or an email. When in flight mode, I don’t have this reflex of mentioning that idea of my phone in the background. And that I think is something our brain does a lot.

Thomas:

Knowing that something could alter, will make it that will somewhat monitor it, will make some room for the parallel processing of this potential information or event-altering. And making it that you kill potential distraction is something that could maybe help actually people concentrate because they don’t have to make some room for that kind of potential disturbances even when they don’t occur. That’s maybe the problem with cell phones is that they’re not only disturbing when they send you a notification, they’re also disturbing by the very present that they are there.

Oscar Trimboli:

Whether it’s interviewing Dr. [Rami 00:00:29:31], Dr [Stefan 00:29:32], or Dr. Thomas in these last three episodes, there’s a consistent recurring theme. Active mobile phones are the number one barrier when it comes to listening. And it’s only [inaudible 00:29:49] force by our own deep listening research. If you want to download a copy of that, just visit oscartrimboli.com/research.

Oscar Trimboli:

There was a huge smile on my face when Dr. Thomas said there’s a huge difference for him between switching your phone to silent versus flight mode. It’s all about where your attention is focused. I was pretty happy that he turned his phone to flight mode for this interview. I know we had a better interview for you as a result. It’s such a simple tip, but imagine if you did that every time you spoke or listened to someone else, whether it was in a one on one situation, in a room, or anywhere else.

Oscar Trimboli:

I have to say I was challenged by the cocktail party example that Thomas discussed. I felt challenged to the core about what deep listening really is. He said there was such a massive ability for the mind to parallel process not only environmental noise, but what’s being said by the people around you. Those kinds of places are my worst introvert nightmare. Yet, in Thomas’s example, many of my listening assumptions were challenged about the capacity to be focused while you’re listening and yet right at the end he said, and he reinforced, that to listen deeply, this is a task that requires focus and you can only deeply listen to one person at a time.

Oscar Trimboli:

I’m intrigued what you took out of the episode and what you’ll apply today, tomorrow, and next week. Please, I love to hear from you. Please send me an email podcast@oscartrimboli.com and tell me what you’ve applied from the last three episodes where there’s been a big theme around focus, attention, and how to overcome distraction.

Oscar Trimboli:

Or even better if you’d like to record a message on your phone or via the website, you know I’d love to listen. Together we’re on a quest to create 100 million deep listeners in the world and it takes a committed tribe of leaders like you to help make this impact beyond words. So if I could ask that you recommend the Deep Listening podcast to just one person you know, if everybody who listened to this podcast did that, we could achieve our quest of 100 million deep listeners in the world in only 36 months.

Oscar Trimboli:

I hope you enjoyed today’s episode. Thanks for listening.

Oscar Trimboli:

(silence)

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