Thread: Dual n-back training: potential tool for lucid dreamers

A couple years back I became interested in dual n-back (DNB) training: a game designed to challenge its player's working memory. Later I became interested in lucid dreaming. The more I read about both topics, the more I began to make a link between the two. In fact, when I searched for "n-back" on Dreamviews, I was actually surprised to find out that DNB has yet to have been discussed here!

In short, the game flashes a series of sounds and pictures on the screen, which the user must memorize. In 1-back mode, a player needs to recall what happened one instance ago. Once you get good at that, the game increases in difficulty by asking you to recall what happened two instances ago (2-back), and so on. It's incredibly challenging. Anyway, the idea is that since this training does such a good job at activating the parts of the brain associated with working memory, perhaps it would do well to increase one's IQ (something generally considered to be set in stone). There's been at least one study so far that has made the correlation between DNB training and IQ improvement (which admittedly has been subject to criticism). That's interesting, but more interesting to me is the implications it has on lucid dreaming. If you're interested in learning more about general DNB stuff, gwern.net hosts a very thorough FAQ on dual n-back training. You can also find a pretty decent online DNB community at the relevant Google Groups page. The Brain Workshop seems to be their preferred DNB game. I also found a decent version for my iPhone called "iBrain."

Now that you have an idea what DNB is about, let's talk about how it relates to our passion: lucid dreaming. While I was reading through Gwern's DNB FAQ, I kept noticing "dream recall" popping up in the testimonials. Note that these guys aren't in it for dreaming: DNB is about intelligence training. Dream recall seems to be an often-cited side-effect of the training:

Originally Posted by negatron

One perhaps coincidental thing I noticed is that dream recollection went up substantially.

Originally Posted by Ashirgo

I have also experienced better dream recalling, with all these reveries and other hallucinations included ;)"

Originally Posted by Jan Pouchlý

Better dream recall.

Originally Posted by TeCNoYoTTa

I also want to report that after training on DNB I found that I am dreaming almost every day...by the way I remember that this effect was not directly after training...unfortunately I stopped using DNB from about 2 months or something like that and now I dream less.

Originally Posted by Chris

One thing I have noticed is the recollection of a number of very unpleasant images in dreams. Specifically, images of bodily disease, mutilation, injury and post-mortem decomposition. I find it difficult to believe it's just a coincidence, because I can't remember when I last had such a dream, and I've had maybe half a dozen since I started dual n-back. But perhaps it's simply owing to better recall.

Originally Posted by reece

Dream recall has increased significantly as has lucid dreaming.

Naturally, I became interested in learning more about the relationship between DNB, working memory, and dream recall. The obvious explanation is that since a user is exercising recall during DNB, that ability transfers over to dream recall. Since I consider dream recall my number one goal as an aspiring oneironaut, this is more than enough motivation for me to start a daily regimen of DNB training.

But perhaps DNB can help lucid dreaming in a way more directly than just by increasing dream recall. I became suspicious of this after learning what areas of the brain DNB activates.

Originally Posted by Working memory capacity and its relation to general intelligence

More importantly, significant correlations were observed between RAPM [Raven's Progressive Matrices, a non-verbal intelligence test], n-back [a superset of DNB], and activity in DLPFC [dorsolateral prefrontal cortex] and ACC [anterior cingulate cortex]. In fact, the correlation between RAPM and event-related activity to lure trials [a tricky n-back] was particularly striking (r ¼ 0.54) and remained significant even when performance on non-lure trials was partialled out. Finally, the correlation between lure performance and RAPM was almost completely accounted for by lure-trial activity in DLPFC. That is, the percent-signal-change in DLPFC associated with lure trials accounted for 92% of the covariance between lure performance and RAPM, suggesting that the WMC/executive attention/g relation is mediated by activity in DLPFC.

[Link]

By the way, a "'lure trial' is "basically B-R-B-A in a 3-back session. Here the second b "lures the mind" since it's almost 3-back and therefore takes alot of executive control not to press the L button." - Pontus

Originally Posted by Does excessive memory load attenuate activation in the prefrontal cortex? Load-dependent processing in single and dual tasks: functional magnetic resonance imaging study

When subjects perform single tasks as well as dual tasks at different levels of difficulty, comparable activation patterns for both conditions seem to emerge in the DLPFC, indicating that both single and dual tasks enhance activation with increasing load in that region.

[Link]

Originally Posted by The Psychophysiology of Lucid Dreaming (by Stephen LaBerge)

To summarize, an elevated level of CNS activation seems to be a necessary condition for the occurrence of lucid dreams. Evidently the high level of cognitive function involved in lucid dreaming requires a correspondingly high level of neuronal activation. In terms of Antrobus's (1986) adaptation of Anderson's (1983) ACT* model of cognition to dreaming, working memory capacity is proportional to cognitive activation, which in turn is proportional to cortical activation. Becoming lucid requires an adequate level of working memory to activate the pre-sleep intention to recognize that one is dreaming.This level of cortical and cognitive activation is apparently not always available during sleep, but normally only during phasic REM.

[Link]

Okay, so isn't it interesting that n-back training does so well at activating the dorsolateral prefrontal cortex (DLPFC)! A couple years ago, Dreamviews user I H8 Reality pointed out one hypothesis which links the DLPFC to lucid dreaming:

Originally Posted by I H8 Reality

According to Allan Hobson the differences between the self-awareness, working memory and executive functions, and consciousness experienced in waking life and its loss in dreaming can be explained by deactivation of the dorsolateral prefrontal cortex during REM sleep (The Prefrontal Cortex in Sleep, 2002).

The Dorsolateral Prefrontal Cortex (DLPFC) is responsible for executive functions and working memory. As a consequence of deactivation of the DLPFC during sleep, executive functions such as self-consciousness and analytical thought are severely impaired during dreams. (The Prefrontal Cortex in Sleep, 2002).

In his book The Dream Drugstore(2001-pg 97) Allan Hobson proposed that lucid dreaming is the result of DLPFC activation during REM sleep, and that working memory resides in the DLPFC which is deactivated during sleep and results in the bizarreness and mute executive functions associated with dreams.

I really wish there was an fMRI study out there which looked at the DLPFC during a lucid dream. Until then, Allan Hobsin's speculation is the best I can do. So under that hypothesis, in addition to improved dream recall, perhaps DNB training will improve one's ability to become lucid by way of strengthening the DLPFC.

But that's not the only part of the brain that n-back training activates that has interesting implications...

Originally Posted by Differential dorsolateral prefrontal cortex activation during a verbal n-back task according to sensory modality

Functional neuroimaging studies carried out on healthy volunteers while performing different n-back tasks have shown a common pattern of bilateral frontoparietal activation, especially of the dorsolateral prefrontal cortex (DLPFC). Our objective was to use functional magnetic resonance imaging (fMRI) to compare the pattern of brain activation while performing two similar n-back tasks which differed in their presentation modality. Thirteen healthy volunteers completed a verbal 2-back task presenting auditory stimuli, and a similar 2-back task presenting visual stimuli. A conjunction analysis showed bilateral activation of frontoparietal areas including the DLPFC. The left DLPFC and the superior temporal gyrus showed a greater activation in the auditory than in the visual condition, whereas posterior brain regions and the anterior cingulate showed a greater activation during the visual than during the auditory task. Thus, brain areas involved in the visual and auditory versions of the n-back task showed an important overlap between them, reflecting the supramodal characteristics of working memory. However, the differences found between the two modalities should be considered in order to select the most appropriate task for future clinical studies.

[link]

Interesting stuff! While n-back training activates many other areas besides the DLPFC, two parts that are especially interesting are the anterior cingulate cortex (ACC) and the superior temporal gyrus (STG). Here's why:

Originally Posted by What Dreams Are Made Of NEW TECHNOLOGY IS HELPING BRAIN SCIENTISTS UNRAVEL THE MYSTERIES OF THE NIGHT. THEIR WORK COULD SHOW US ALL HOW TO MAKE THE MOST OF OUR TIME IN BED

Another active part of the brain in REM sleep is the anterior cingulate cortex, which detects discrepancies. Eric Nofzinger, director of the Sleep Neuroimaging Program at the University of Pittsburgh Medical Center, thinks that could be why people often figure out thorny problems in their dreams. "It's as if the brain surveys the internal milieu and tries to figure out what it should be doing, and whether our actions conflict with who we are," he says.

[link]

Originally Posted by Dreaming and the brain: from phenomenology to neurophysiology

Some lesions, especially those in medial prefrontal cortex, the anterior cingulate cortex and the basal forebrain, are associated with increased frequency and vividness of dreams and their intrusion into waking life.

[link]

Originally Posted by Visualizing Out-of-Body Experience in the Brain

Two patients have been described in whom out-of-body experiences were evoked by electrical stimulation of the right temporoparietal junction. The patient described by Penfield had a floating feeling without autoscopy, induced by electrical stimulation of the posterior part of the superior temporal gyrus, anterior to the angular gyrus.

[link]

Perhaps, then, DNB might help us by way of activating the ACC, which apparently facilitates problem solving and conflict resolution while dreaming as well as it having to do with dreaming frequency and vividness. It's also very interesting that the STG (another DNB-activated area), through electrical stimulation, can induce out-of-body experiences.

I, personally, prefer to stay practical. I speculate that DNB may improve dream frequency, lucidity, and vividness by way of the DLPFC, ACC, and STG, but that's really just speculation (and not even very good speculation: I'm "carwashguy," not "neuroscientistguy"). After all, there's controversy about whether or not DNB training even improves working memory in the first place. That said, the main thing prompting me to practice DNB daily is the anecdotal evidence of dream recall improvement. But really, only time will tell if DNB will help even that.

Very interesting stuff, thanks for sharing it. As you said in closing, you prefer to stay practical. So what specifically would be the practical approach? Is this something that one could do on a daily basis before bed? Are we talking 5 minutes? An hour? Basically, how would you set up the experiment for yourself.

I've been practicing DNB for 30 minutes a day. I train in the evening, but perhaps it would be better to do it nearer to bedtime.

Sounds interesting. I tried it and it's not a bad a game in itself. I'd like to try experimenting with it. I'll start doing 20-30 minute sets before I sleep. Maybe even more if my work flights lack any action. lol

Originally Posted by carwashguy

A couple years back I became interested in dual n-back (DNB) training...

carwashguy: That's an interesting point you make. Funnily enough, back in 2009 on the DNB mailing list, I posted on a very similar quote:

But I think at that time the DNB FAQ was still fairly short and I hadn't collected all the testimonials I had, and it didn't occur to me that there might really be something there. (I mean, people also report increasing dreaming after starting heavy use of spaced repetition systems like Anki/Mnemosyne/SuperMemo, so it could just be that extra brain work causes dreaming.) So, no time like the present to stick in the FAQ and steal some of your quotes:

EDIT: apparently there are fascist settings that will not allow me to post with URLs. The first link is to a thread in the Google Groups (search for 'gwern lucid dreaming') and the second is a link to the new subsection of the DNB FAQ dealing with lucid dreaming.

Originally Posted by gwern

carwashguy: That's an interesting point you make. Funnily enough, back in 2009 on the DNB mailing list, I posted on a very similar quote:

But I think at that time the DNB FAQ was still fairly short and I hadn't collected all the testimonials I had, and it didn't occur to me that there might really be something there. (I mean, people also report increasing dreaming after starting heavy use of spaced repetition systems like Anki/Mnemosyne/SuperMemo, so it could just be that extra brain work causes dreaming.) So, no time like the present to stick in the FAQ and steal some of your quotes:

Ah, I see you've been checking your referrals. I'm flattered to have prompted you into updating the FAQ! One thing I hadn't learned until after making that post is that it seems while heat stress can increase the length of stage-3 sleep during night, mental exercises apparently can increase the length of REM sleep. I doubt this is the mechanism behind the reported increased dream recall, though. Since, I'm not sure we could say that more REM necessarily means better dream recall per se.

Originally Posted by carwashguy

Ah, I see you've been checking your referrals. I'm flattered to have prompted you into updating the FAQ!

Actually, I have a Google Alerts set up for dual n-back so I catch discussions and mentions of n-backing elsewhere; more than one of the entries in the Benefits section leads out into the wild wooly Web if you check. (Recently I did check the Google Analytics stats and noticed the hits coming from dreamviews.com, but that came as no news.)

Originally Posted by carwashguy

One thing I hadn't learned until after making that post is that it seems while heat stress can increase the length of stage-3 sleep during night, mental exercises apparently can increase the length of REM sleep. I doubt this is the mechanism behind the reported increased dream recall, though. Since, I'm not sure we could say that more REM necessarily means better dream recall per se.

An interesting question. I would guess that the longer REM sleep is, the more there is to remember, the more time there is for you to notice it's a dream, the more time for the dream to get strange enough that you realize it, etc. Kids dream more than adults, after all, and don't they report more dreams? I have vague memories that I had long continuing dreams as a kid, and I don't as an adult. (I have a Zeo, and my (much) younger brother has REM sleep in blocks of, like an hour or more, while I rarely get over 20 minutes.)

Originally Posted by gwern

An interesting question. I would guess that the longer REM sleep is, the more there is to remember, the more time there is for you to notice it's a dream, the more time for the dream to get strange enough that you realize it, etc. Kids dream more than adults, after all, and don't they report more dreams? I have vague memories that I had long continuing dreams as a kid, and I don't as an adult. (I have a Zeo, and my (much) younger brother has REM sleep in blocks of, like an hour or more, while I rarely get over 20 minutes.)

Those are good points, but there's a couple of issues. Apparently, while infants spend upwards of 50% of their sleep in REM, this number starts leveling off after about 5 years of age. (See figure 6.) There's a bump at the 19-30 year old section. So, assuming your brother is younger than 19 and you're older than 19 but younger than 30, running with your ball, you'd be better off than your brother at recalling dreams. (By the way, if your brother is seeing larger chunks of REM than you, it's possible he's just getting more sleep. Hour-long REM cycles come close to the time when you wake up, so it's possible you're waking up before you get to them. On the other hand, kids need more sleep in total than adults do, so that might have something to do with it. Still, you should be getting more REM than 20 minutes during the morning hours. Maybe you should look into that. Maybe you have sleep apnea or something. Or perhaps, if the reviews on Amazon.com are any indication, the Zeo might not be accurate enough for us to come to that conclusion.)

Secondly, I dug up the reference where Laberge talks about mental exercise and REM:

Originally Posted by Exploring the World of Lucid Dreaming

Most people assume that a major function of sleeping and dreaming is rest and recuperation. This popular con-ception has been upheld by research. Thus, for humans, physical exercise leads to more sleep, especially delta sleep. Growth hormone, which triggers growth in children and the repair of stressed tissues, is released in delta sleep. On the other hand, mental exercise or emotional stress appears to result in increases in REM sleep and dreaming.

The thing is, I'm having trouble verifying this. It's getting late, so I'll have to do more research tomorrow. It might even be based on Laberge's own unpublished research--dunno. So, right now it's unclear to what extent mental exercises extend REM sleep.

is there a direct link where we can access this game? i badly want to improve my shrot term memory or Working memory.

Originally Posted by dreaminglucid.blogspot.com

LaBerge (1990) advocated the view that the high level of CNS activation is evidently linked to a high level of cognitive function involved in lucid dreaming, and that becoming lucid requires sufficient level of working memory which is necessary to recognize the dream as a dream.

Perhaps working out our working memory in waking life will increase our working memory in dreams, therefore causing more frequent lucidity.

Source: lucid dreaming library: Cortical activation and working memory

So I've been doing it a couple of days. I played about 15 games last night.

I listened to a lucid dreaming self hypnosis track that has been helpful for me in the past. In the middle of the track I was in a dream and could hear myself repeating "Mind Awake. Body Asleep." I noticed that in the dream I was clearly looking at my computer with dreamviews open too. lol

I slept well the rest of the night until one of my roommates alarms went off at 4 am twice. Usually I get up around this time to workout, but I needed to rest my legs some more. After I went back to sleep I repeated the same mantra a little, and had what felt like an AP and a Lucid. I'll continue playing at night.

interesting cheers. its a much simpler and more lucid oriented rc though to just keep on asking yourself throughout the day 'how did i get here' or 'what have i been doing for the last few minutes'

On a more reductionist note, increased working memory may be useful because of the non linear features of dream plots.

Say you've seen a movie, you can recall more and more information by going through the plot as it's linear and makes logical sense. In a dream it doesn't necessarily work this way. For example in a dream the other day I turned around in my kitchen and was on a stage. This is completely illogical and so harder for the brain to remember. Increased working memory would mean that you can remember more of the jumble of random events that occur in your dreams and probably lowers the likelihood of just remembering fragments.

Also, I posted a thread regarding the temporoparietal junction the other day. This part of the brain has a lot to do with balance and spatial awareness as it's connected to the inner ear, so it looks like there is a strong link between it and OBE's/WILD vibrations etc.

That's my take on it from what I've learnt in psychology so far, but I'm definitely going to give this a go, it's a fantastic idea and there are a number of reasons why it would work! In fact this could be third year dissertation material - thanks!

I've used the suggested Dual N-Back training program to do some Dual 2- and 3-Back games lately. More exactly, I did about 4-8 games a day for the last 4 days or so, which I find to be not that much (I almost can't imagine it having had an impact on my memory yet).

Last night, I went to sleep at around 11pm and woke myself with an alarm at 3am, when I have had one or more dreams already. Without getting out of bed, I took my laptop from under my bed and did about 4 Dual 3-Back games (with very mild success compared to the games I do during daytime). I went to sleep again trying to WILD. The technique was that I imagined myself (my dream body) swimming and walking while falling asleep to transition directly into a dream where I was doing that, but I didn't do very well.
After a few minutes (that's what it felt like) of being asleep and dreaming a DILD happened: Placed in a dimly lit club- or bar-like room with a few tables and people standing around who were talking to each other, I immediately tried to stabilize the dream (which wasn't very lucid) by feeling the table near me with my hands and looking at the people standing around it. It didn't give me nice clarity, but it helped a tiny bit. I told the man next to me to tell me I'm dreaming the next night I'm dreaming, so another DILD would happen, he seemed extremely passive though and I'm not sure he got what I wanted to tell him.
I walked around the table to tell the other people the same thing, but they were all good looking girls which got me aroused very quickly. When I finally got to the other side of the table (I'm not sure whether I actually talked to anyone else or not, the dream already started to fade) it came to some very short penetration with one of the girls, and from there on I can't remember anything else.

So it seems I had some success with this (WBTB + Dual N-Back training) and I will do the same thing again tonight, though I might do some more games before going back to sleep. Also, I'm not sure whether this has happened purely because of the Placebo effect or not, but I'll probably find out more about that the next few nights.

despite being a somewhat difficult game especially on 3-n back. I can really see why this would benefit lucid dreaming

So I tried again the next two nights, but I didn't to any training during the day. The WBTB sessions were really short and I was doing them a bit sloppy, so there weren't any LDs. I think I have to wake up more during WBTB, but then I fear I won't fall asleep anymore :/ (and when that happens, I usually can't fall asleep for 15+ mins, which is long for me).

My recall disappeared in the week somewhat, the last two nights since playing this game it has returned somewhat.

I'm reluctant to draw a link between the two at the moment as I haven't played it lots. However I'd love to improve my working memory and fluid intelligence anyway so I'll keep at it for a while longer.