Lucid Dreaming - Sending a Signal to the Waking World

Lucid Dreaming seems to be a bridge between the waking and dream worlds. You are dreaming, yet you are conscious of dreaming and capable of having rational thoughts during a jumbled dream.

Being lucid doesn't mean that you have full control over your dreams, despite being aware that I'm dreaming I still find that I am compelled to "play along" with the dream that I'm given. So, for example, if I find myself dreaming of a street scene, I can't magically transform it into countryside. In order to change the scenery I have to make the change fit into the story somehow, even if the scene-change is something as crude opening a shop door and "knowing" that it takes me to the countryside.

All this is wrapped in the fact that (for me at least) lucid dreaming is a constant struggle to remain lucid, it doesn't take much to lose lucidity and slip back into a normal dream. 

So when I suggested sending a signal from a dream in this blog-post, I thought it unlikely that I'd ever be able to remain lucid and have the presence of mind to consciously send a signal to the Zeo Raw Data (via ZeoScope) marking the lucid dream.

I'd been briefly practicing what sort of a signal to use before going to sleep every night, hoping that it'd stick inside my head if I was fortunate enough to have a lucid dream. Given that the signal has to be based on eye movements I was fairly limited in what I could do, but the practice sessions showed me that flicking my eyes from side to side just seemed to produce a very noisy signal and something that could be interpreted as EMG noise from my forehead, so I settled on eye movements to the right, then centre, which produced a nice peak on the raw EEG data (it is this type of peak that the Zeo filters to use for its EOG signal).

Because the eye movements were forced as far right as I could manage the amplitude of them rose above the normal eye movements of waking and REM. 

(Normal eye movements during a period of REM (right to centre first, followed by left to centre)

On Wednesday night I became lucid in a dream and managed to stop and send a signal using my eyes that was picked up by the Zeo.

The first thing that I remember about the dream was that I was late to get to a party and I still had to stop off and buy a bottle of something to take along. I lifted up and flew along the coast of the Thames Estuary not far from where I live. 

This was the thing that prompted me to become lucid. Flying is such a break from the everyday laws of physics that it jolted me into realising that I was dreaming.

So, I went along with the dream, flying to the party but stopping off at a small stone-clad Welsh off-licence (I have no idea why I ended up in Wales). As I landed and my feet touched the ground I remembered that I was wearing the Zeo headband and recording the raw data, so I darted my eyes sharply to the right and centred them again.

Then I thought, "That's just one, maybe it'll get lost in the other data", so I repeated it 5 more times, then bought my wine and Jaffa Cakes, lifted into the sky and headed for mainland Europe (where the party was apparently).

Shortly after arriving at the party (which turned out to be in a 1970s church hall), I woke up and glanced at the clock before falling asleep again.

In the morning I found it easy to see the signal that I'd recorded. The peaks were a lot larger than my typical eye movements. The first peak is my initial signal, then after a pause I gave 5 more right-eye movements.

So, not as significant as a signal picked up by SETI but still, this is a signal from the dream-world to the waking world. It actually reassures me because several people have asked me, "How do you know that you're not just dreaming that you know you're dreaming?" implying that lucid dreaming is itself a dream. This shows that it isn't. At the time of the signals, I remembered that I was actually asleep in bed and not outside an off-licence in Wales and although I was still standing on the cobbled street and not able to sense the waking world I was able to make an impact on it via this signal.

From the Zeo raw data it seems that a broken night played a part in triggering this dream, and I suspect that respiratory arousals were the cause again as I wasn't wearing the Rematee belt. A rough breakdown of the time surrounding lucidity is as follows...

• 04:34:45 Woke from a long stable period of N1/N2 (light) sleep
• 04:39:15 Entered REM (from wake)

Repeated awakenings and a mixture of N1/N2 and REM until... 

• 05:00:15 Entered stable REM
• 05:03:26 Began to signal lucidity
• 05:03:37 Gave last eye movement of lucidity
• 05:06:14 Woke and looked at the clock before going back into REM again
• 05:11:14 REM ended

So this places my lucid dream within REM, which was the subject of speculation for years until Stephen LaBerge confirmed that lucid dreams are actually REM dreams. 

Jeff Warren also has a good explanation of the technique in this exerpt from his book, "The Head Trip". 

Stephen LaBerge, William Dement, Lynn Nagel and Vincent Zarcone took things a lot further and even recorded morse code signals from a lucid dream via muscle-movements.

I'm still not any closer to seeing a trademark brainwave pattern of lucid dreaming, but I suspect that this is due to the single site EEG. 

I'd like to practice this further and if I'm fortunate enough to be able to do this again I'd like to try to repeat the signal every 60 seconds (as it appears to me in the dream), or at key points in the dream (such as taking off and landing, meeting a person etc etc) it would be interesting to see if these signals can be used as markers to chart the flow of time through a dream.  

Actigraphy: Only Part of the Story...

Actigraphy, or the monitoring and charting of the movement that we make, is an established means of monitoring sleep, albeit not a very detailed one.

The patient wears a movement monitor(s), the data from which is essentially processed as "not moving = asleep" and "moving = awake". As you can see, this can only really tell us the two states and not provide more accurate sleep stage information. 

Actigraphy is not a substitute for a full sleep study, however the data it provides can be used to augment a sleep study.

There are many consumer actigraphy devices on the market today, and also many intended for professional use. I am only concentrating on the consumer devices. The professional devices are a lot more sophisticated.

A few months ago I tried out a couple of the consumer devices myself, and pretty much dismissed them as I found that they didn't really add anything to my existing set-up consisting of nasal airflow, oximetry, capnography, IR camera and the Zeo.

First let's take a look at the devices and the data they provide:

 The first device is the "Wakemate". This consists of a small circuit board that fits inside a wrist-worn sweatband.

The on-off switch protrudes directly from the circuit board, which had me worrying that it would soon break after repeated use, however it seemed secure enough once tucked inside the padded band.

Once paired with your smart-phone, the device uploads its data via bluetooth. 

The second device is the "Lark".

This is similar to the Wakemate, although it felt sturdier and had a nice charger dock with it.

The electronics are encased in a sealed unit which is then inserted into the wristband.

 To give a fair test to these gadgets, I wore them both on the same night, both on my non-dominant wrist. Once I'd downloaded the data I was able to find a chart of time vs movement. Both charts aligned well:

 (Wakemate - top. Lark - bottom)

The Lark's graph is more detailed than that of the Wakemate, and shows some analysis has already taken place on the data. It highlights large movements blue signifying periods of wakefulness and leaves smaller movement orange.

More data is available from both devices, such as total time awake, total time asleep, time in bed etc.

I then compared the above graphs with the Zeo hypnogram from the same night...

By doing this some of the limitations of actigraphy become clear. I was actually awake for an hour between 1:15am and around 2:15am. During this time I was lying still, hoping to fall asleep again. The actigraphy-based devices interpret this period of stillness as sleep, albeit with some movement. Being still does not equate to being asleep. Consequently, if a partner is moving around in the same bed as you, it is possible that the actigraphy would detect their movement. 

However, it was good to have my broken REM (around 4am) confirmed by the actigraphy devices. At this time I was suspecting that the Zeo was detecting some of my REM as wakefuness (a suspicion that I later ruled out). During normal REM sleep muscle atonia prevents us from moving, so seeing that I actually moved during REM added to the growing evidence that I really did wake during REM sleep.

Whilst looking into actigraphy, I also found a popular iPhone app that makes use of the accelerometer in the phone. It's called Sleep Cycle.

The phone is placed at the top of your bed, near your head, it then monitors your movement (based on how the bed moves) in the night.

It's actually very simple, but I found that it was surprisingly accurate when compared to the Zeo. It correctly identified two periods of being awake and one period of deep sleep. I suspect in a healthy sleeper, it would confuse REM sleep and deep sleep.

I have also used the AxBo "SleepPhase" alarm clock. This is a clock that comes with two wristbands which wirelessly communicate with the clock. Each wristband contains a sturdy sealed module that detects movement. The intention is that two people can use this clock.

I purchased the AxBo before I had any other consumer devices. I still had the oximeter and the capnograph, but no Zeo and none of the actigraphy devices mentioned in this blog-post.

However, after purchasing the clock and using it for one night, I realised that it doesn't actually show sleep stages. I probably should have realised beforehand. 

The sensors are actually very sensitive, and show more movement information than anything I've previously discussed here. They can actually show which axis the movement takes place along. However, after a couple of nights of wearing the band and looking at my movement data I thought "Okay, but so what?". I wasn't actually sure where to go from there as I wasn't interested in the clock's ability to wake me up at an optimal time, more in its ability to chart my sleep.

A device for sleep and wake?

As part of a health kick (and weight loss), I have been using a device called "FitBit". It looks like a very slick pedometer, but it is acutally a lot more sensitive. It uses an accelerometer to determine steps taken in day, how many flights of stairs you climb, how many calories burned, and sleep-actigraphy similar to the devices mentioned above.

The difference between this and a standard pedometer is that this can show you, in graph form, when the activity occurred during the day.

The bonus with the FitBit is that the "FitBit Dashboard" lets you link your data with other "Quantified Self" devices such as the Withings bathroom scales, which in turn lets you link your data with your Zeo ZQ. 

This all adds up to a feeling of being part of a bigger programme, a programme that encourages you to look at all aspects of your health see the effect that lifestyle changes have on your data (and on you). You can actually quantify your exercise, which in turn reveals a greater weight-loss which hopefully will have an effect on my sleep quality, which will be seen in the ZQ.

Anyway, I've lost 9lb so far and I plan to carry on until I get down to my target weight and then I'll blog the combined results.

Quantifying the exercise that I do in terms of steps taken, flights climbed and calories used should allow me to see a correlation between FitBit exercise and Zeo deep sleep, maybe a correlation with sleep and a quantified "power-down hour" in the evening; who knows, it may even reveal a REM correlation too.

How did FitBit do when compared to Zeo for sleep analysis?

 

Again, it compared well, with the exception mentioned above (that being still in bed does not equate with being asleep), and to be fair, the Zeo 30 second data does show me drifting into and out of sleep at a couple of points in the large period of wakefulness at the end before I eventually gave up and got out of bed, but for the most part I was awake and just being still.

However, none of the actigraphy devices show sleep-stage data, and (as I'm learning from the fascinating "Quantified Self" movement) more data means a greater ability to "hack" yourself or to help yourself.

By using actigraphy as the sole gauge of good sleep you are blind sleep stage data. Having access to my sleep stage data allows me to target specific stages that I think need attention: If your slow-wave-sleep (deep) is too low then you can exercise to increase it. If your REM is broken or too low then you can try supplements and mental exercises to put it right. This is not possible if you can only tell that you were moving when you were supposed to be asleep.

Having easy access to my sleep stage data set me on the road to investigating why my REM sleep was broken. I was easily able to correlate my drop in oxygen levels to REM sleep using a cheap pulse-oximeter, and from there, with the addition of another channel - airflow, discovered that REM-related apnoeas were the cause. From there with the addition of another channel (motion activated IR camera) I was able to add "positional" and "obstructive" to that diagnosis. Giving me the full diagnosis of "Mild REM-related positional obstructive sleep apnoea".

With a correct diagnosis, I was then in a better position able to properly assess treatments (more of those in a later blog).

This would not have been possible had I only known that I moved during my sleep as the correlation with REM would not have been detectable, although, to be fair,I could have gone onto diagnose apneoa without sleep stage data, it would have not given me the full picture. In fact looking at my sleep using only actigraphy (when I only had the AxBo), made me pretty much give up after a couple of nights. Nothing made me want to look into my sleep further until I had the Zeo and Oximetry data.

I continue to use the FitBit during the day, but I eventually consigned the other sleep-actigraphy gadgets to the bottom drawer until I realised that by using these devices slightly differently that I could use them to add additional channels to my setup, in theory anyway...

A cause of poor sleep is Periodic Limb Movement Disorder, in which the sleeper's legs twitch and move involuntarily during the night, causing them to wake up, or partially wake up (micro-arousal), both of which lead to disturbed sleep. 

By fixing the actigraphy devices to the sleeper's ankles it would be possible to detect this. It might even be possible to detect the leg movements as a cause of waking up, rather than as a consequence of it if the devices could be accurately synchronised. The only thing that concerns me about this is that the timescale on the axis of the movement graphs may not be detailed enough to show the movements occuring before an awakening. Oddly, I think the Axbo would be best suited to this, as the software allows the most flexibility in analysing the data. However, this will have to remain a theoretical test as I don't have an issue with PLMD.

(All device photos are from product websites unless indicated)

Brainwaves

Imagine a brain, like the one in the photo, made from a string of fairy-lights. Imagine billions of lights in the brain, all blinking in a seemingly random pattern, passing electricity onto each other in a pattern that only makes sense to itself. Now imagine that wires can grow directly between bulbs that commonly light at the same time, making a connection between them.

That's pretty much what is happening inside our brain, except the fairly lights are neurons and the wires are neural connections. The power comes via tiny electrical impulses and electro-chemical messengers.

Imagine that, like the one in the photo, your head is made of glass and that it were possible to record how fast and how bright the majority of surface lights in a particular area were flashing.

That's roughly what an EEG can achieve. 

It's complicated in there, and anyone who says that they have a complete grasp of what is going on inside is lying!

...but we have a few clues to guide us.

We can use an EEG to record the voltages that are present near the surface of various areas of the brain.

Essentially, an EEG is a volt-meter recording the voltages that escape to the surface via adhesive electrodes glued to the skin.

Straight away, this is a limitation because we are therefore oblivious to the voltages that are buzzing away in deeper areas of the brain and multi-lead EEGs can look at many areas of the brain at the same time.

However, we are still able to deduce an awful lot from a single site EEG.

These are slowly coming onto the market for consumer use, one that I've had for a while is the X-Wave. It's a large headset with a single forehead electrode and an ear-clip. The voltage from your forehead is monitored and by comparing the signal pattern to a known pattern for either "concentration" or "relaxation" the attached computer is able to deduce whether you are in either of those mental states. 

This is a neuro-feedback system. You can spend ages watching the flicking graphs and wiggling lines playing "trial and error" trying to make them respond as you wish. When you achieve the desired pattern you are given positive reinforcement by the computer, making it easier to achieve that state again. Oddly, being taught what to do is tricky, but given half and hour of experimentation you'll find that you soon pick up what to do.

With a little practice I was able to achieve 100% concentration...

...and around 80% "Meditation" which isn't that easy when you are desparate to grab a screenshot of being "relaxed"...

There are also computer games written for the X-Wave which allow you to control them by either concentrating, or relaxing. A good "real world" example is the "Star Wars Force Trainer" where you wear a similar headpiece and try various thought patterns until you find the one that makes the ball float.

I first purchased the X-Wave because I thought it would help me to determine sleep stages if worn when asleep. It would have been an uncomfortable night as the headset isn't really condusive to a good night's sleep. However, it doesn't (yet) have the ability to record and playback data, nor does it (yet) allow you to see the raw waveform, although I believe that this is something in the pipeline, although this would still leave the user needing a knowledge of EEG interpretation to be able to determine which sleep stage a sleeper was in.

The XWave may be useful for games and biofeedback, but it wasn't able to do what I wanted, nor did the PC interface become available as was available for pre-order on the website.

I then purchased the Zeo Bedside Sleep Monitor which uses EEG technology to do what I wanted (determine and record sleep stages automatically). Then, with updated firmware and a home-made lead, you can connect the Zeo to a computer and see an awful lot of what is going on in your brain. Granted, this is still a single channel EEG, so it is only looking at one area of the brain, but still the amount of activity that you can see is astounding!

First I'll mention some of the different types of brainwave that I've seen with this system. These waves are all recordings taken from my brain whilst I've been asleep. 

Generally speaking, the thing that determines one type of wave from another is its frequency (how many times it cycles per second), although some features jump off the screen at you such as "K-Complexes" and "Sleep Spindles", both features of Stage 2 NREM sleep.

It is possible that some features found in our brainwaves also serve a function, or at least they show when the brain is carrying out a particular function. For example, K-Complexes can be induced in a sleeping person by external noises. It is thought that the K-Complexes are a response to a noise that the sleeping brain has evaluated as not being a threat.

Sleep spindles also seem to be connected to the outside world. They represent when the brain is not consciously processing input from the world outside. In my oversimplified world I tend to think of them as little bundles of barbed wire that sit on the boundary of sleep and wake somehow shouting "La la la, we're not listening".

Like K-Complexes and Sleep Spindles, some wave patterns are closely related to sleep stages, such as Deep Sleep, which takes its correct name, Slow Wave Sleep, from the waves that are associated with it - Delta Waves, or Slow Waves.

Just as measuring the voltage from the screen of your television doesn't tell you what programme it's showing, measuring the voltage from your skull doesn't tell you what thoughts are being thought (although it's becomming ever closer http://www.ibtimes.co.uk/articles/290907/20120201/mind-reading-machine-scientists-computer-program-epilepsy.htm ) Trying to detmine what the person is thinking or dreaming about isn't as simple as looking at the brainwaves they produce and then comparing it to a vast dictionary of known squiggles. For one thing, the brain is capable of producing (and does so) many waves at the same time, in the same area of brain. The relative power of these waves can be separated out using FFT algorithms.

However, thoughts and sleep stages are completely different animals, and the Zeo is able to determine sleep stages with a high degree of accuracy (References Shambroom, Fabregas & Johnstone, also here and here), which is after all what it was designed to do. We are just piggy-backing off its ability to show EEG data.

The following is the raw data from a section of sleep. The bottom is a hypnogram (shows the stages of sleep) for a whole night (top-bottom = wake, REM, Light, Deep); the top is the raw waveform for the current 15 seconds) whilst the line in the middle is a record of about 45 minutes of data.

The middle one is the result of the FFT analysis (mentioned above) and represents the types of waveforms in proportion to each other. From this it is possible to determine which is the dominant waveform. 

A good example of this is observing the transition out of slow-wave sleep. (Note the steep drop in the red line).

Click for larger image

It's also interesting to see what happens to your brainwaves while awake and carrying out various tasks.

Normally, the frequency distributions seems to be fairly scattered (the lines are nicely spaced out), but one night I woke around 3am and couldn't get back to sleep, I kept the headband on. It seems that when I was concentrating on reading Twitter the various frequency brainwaves became more focused, leaving Alpha and Theta as dominant.

These grouped together even tighter when I actually tweeted and a form of Beta wave became dominant (although only slightly). I presume the tight grouping is because typing required more concentration and more focused thought. Oddly I received a phonecall while awake, and this shows another pattern.

  Click for larger image

Through playing around with this set-up you learn to spot patterns. For example if I am disturbed in the night by a sound that wakes me you can see a brief period of concentration before I go back to sleep. it would be fantastic to actually see the change in brainwaves during an episode of sleep paralysis or a lucid dream.

This would make a great neuro-feedback system and I plan to use it to test the claims of various products that they are able to "induce delta waves" or "cause trance like theta waves" etc.

Zeo Sleep Monitor

In many blog-posts I'm going to be talking about some devices that I use to monitor my sleep. So I thought it best to explain a bit about them. The first one is the Zeo.

There are two flavours of Zeo, a bedside unit and a new mobile version that pairs with your smartphone.

 

 Both devices consist of a wireless headband containing fabric electrodes which are used to measure your brainwaves using EEG technology. Previously EEGs were confined to sleep laboratories and hospitals. They involved gluing electrodes onto your scalp and connecting them to a computer in order to detect the voltage changes that take place in your brain. Interpreting these EEGs is a skill in itself.

During a full polysomnography sleep study, a sleep technician will manually look at each 30 second chunk of data (epoch) from the EEG (then combine it with data from what your eyes were doing and how tense your muscles were) in order to determine which stage of sleep you are in. Zeo is much neater and doesn't involve glue or wires.

A typical night with Zeo goes something like this:

• When you are ready to sleep, remove the headband from it's magnetic dock/charger
• Place the headband on your head with the block roughly central on your forehead
• Wait for the little symbol of a head to illuminate (that means it has detected a brainwave pattern - always a relief)
• Sleep
• Wake, remove and re-dock headband

Both versions allow you to instantly see how you slept last night but you can also upload and view the data via the Zeo website. The site allows greater analysis of how you slept; you can also complete a sleep journal detailing coffee and alcohol intake, your "morning feel" and various other factors to help you see a cause-and-effect relationship between them and how you sleep.

A device that reads your brainwaves... you know you want one. This is where you can get them from in the UK: http://myzeo.co.uk/

So, what does the Zeo actually measure?

As previously said, it uses an EEG, combined with an EOG (eye movements) and EMG (muscle tone) to determine which state of sleep you are in. It then presents this to you in a colourful graph called a hypnogram.

Whereas a sleep technician looks at every 30 seconds, Zeo examines every second of data and makes a decision, it then amalgamates these into 30 second chunks using a proprietary scoring system.

The makers of Zeo have released a special firmware for the bedside unit that allows you to plug a computer into the port on the back and see the actual EEG and play it back in the morning. You can see all the little blips and squiggles and how they relate to your sleep.

 This, for example, is a "Sleep Spindle" it signifies that I was in stage 2 sleep...

Sleep consists of cycles of deep, light, wake and REM (Rapid Eye Movement). On a formal hypnogram you may see these listed as an N and a number. The N simply means Non-REM. N1 and N2 are considered to be light sleep. N3 (and sometimes N4) are considered to be deep sleep.

Early in the night is when you get the most deep sleep, which then decreases through the night and is "replaced" with increasing amounts of REM

 Hence, a normal hypnogram (sleep stage graph) should look something like this:

Graph taken from "A good night's sleep part one: Normal Sleep" by Dr Sue Wilson.
"Nursing & Residential Care", November 2008

Zeo's hypnograms display data at resolution of 5 minutes. The 30 second resolution graph is available by exporting the data into a spreadsheet program.

This is one of my recent hypnograms from Zeo, and as you can see it's a mess...

That's where the Zeo's journal comes in... WHY is it a mess? Too much coffee in the afternoon? Too much wine in the evening? Is the room too warm? Do I always wake up at the same time in the night? Why is that? Could it be the heating making noises? etc etc.

By looking at the patterns, you can aim to work out why your night is disrupted (if it is). If you are one of the lucky ones who seem to sleep normally then you can aim to improve on that sleep to make sure you feel bright and energetic in the mornings.

What's wrong with my graph?

Looking at the the night shown above, there are a couple of things that jump out:

• Deep sleep - not enough of it, and doesn't follow the pattern of decreasing through the night. This is clear because my body obviously tried to catch-up on deep sleep at 7:30am!
• I have WASO (Wake after sleep onset), but it seems that they are not random, they seem to be clustered around what should be solid chunks of REM. 

These REM disturbances are what I believe leads to episodes of sleep paralysis. I will do a blog post on that later, but there is a good article on Wikipedia about it here: http://en.wikipedia.org/wiki/Sleep_paralysis

So all in all, much to improve on.

I did suspect that I had REM related issues. Maybe a small part of my son's condition is hereditary? Maybe not, maybe it's just coincidence.

For the 10 years that it took to get my son's sleep and breathing under control I was forever listening out for his oxygen alarm. He would stop breathing during REM sleep and the alarm would sound to alert me to it.

I'd then wake up, glance at the alarm on the camera that I'd installed and then go in to rouse him from sleep and get him to breathe again.

This would happen many times a night. Children have a lot of REM! 

Maybe in some way my brain had adapted to not be quite asleep, forever on the lookout for my son's alarm that everyone else in the house slept through (including him)!

My son's breathing is now regulated by BiPAP (A breathing machine that delivers alternating pressures of air via a mask - more about that in another post). That started about 6 months ago, so I thought I would have settled down into a decent sleep routine now. 

I decided to explore and used some of the cameras and monitors that I had used for my son on myself. After a couple of nights I now have a fair idea of why I wake in REM. So, I've decided to be a bit more disciplined about collecting data and recording what I'm up to.

This week I'll be gathering data for 5 nights (Mon - Fri) and will post the data and its mean as a baseline for my sleep, then I am going to try a different method of "fixing it" every 5 nights (Mon - Fri) and average for consistency.

I'll blog the results as I'm going along.

Next post: baseline sleep scores.