Sleep and Consciousness
Individual Differences in Lucid Dreaming
Most of the questions I have asked in my research program over the last almost 20 years have dealt with individual differences in lucid dreaming. So, for instance, I have asked what is the spontaneous incidence of these experiences of consciousness in sleep? I was interested in knowing when this occurred normally. That is when a dreamer wasn't programmed go out and try to have the experience. In a series of studies my students and I found that among college students if I asked them did you ever have a dream when you knew you were dreaming, 58% said they had had such a dream at least once in their lifetime while 21% had had it once or more per month. It's interesting that if you look at certain populations you get remarkable increases in this incidence. From five samples of meditators we got average incidences of once or more per week. It is important to note that among these groups of meditators they were not meditating in order to have lucid dreams. Lucid dreams seemed to be part of a range of positive outcomes that emerged from the practice of meditation. I'm going to argue that this outcome is not superfluous rather it is a fairly central aspect to the practice of meditation.
I also examined the phenomenological content of lucid and nonlucid dreams, wondering if they were similar. We found that it depends on who you ask. If you ask the dreamer, they tend to characterize their lucid dreams as much more remarkable and noteworthy than their non-lucid dreams. This is true at least for those who have had them somewhat infrequently. The more you have them, the more ordinary they appear. Eventually everything habituates. They don't necessarily get boring, you just get used to this state of mind in sleep. Therefore, I think our self-evaluation findings are confounded by novelty .
If on the other hand you ask independent judges' to evaluate lucid and non-lucid dreams, we found that in the main there were very few differences. The few differences are noteworthy. The most obvious, of course is that you know you're dreaming. But this defines the categories. It does also appear to open certain dream potentials. You've got some control over the dream. This we have seen over and over when you're dreaming and you know you're dreaming you can, to a point, control the dreams.
Another difference is that the auditory references are higher in lucid dreams. The fact that this difference was combined with kinesthetic differences seems to indicate that the vestibular system is somehow more implicated. This we substantiated in other research.
Also there are fewer characters in lucid dreams. That's kind of interesting from a psychodynamic perspective. If you view every character in the dream as part of yourself, then fewer of them would imply more integration of the aspects of self. Furthermore, lucidity has the potential to give you an opportunity to further your integration/growth process. I was also interested in the psychological predisposition's which result in people having lucid dreams. Although there were some differences there was nothing that was particularly remarkable. For instance, there was some evidence for lucid dreamers to be more androgynous, that is they were comfortable expressing both the masculine and feminine parts of themselves. Lucid dreamers are more likely to take internal risks like being willing to be hypnotized. They're also more self oriented.
Where we found stronger individual differences was in terms of the superior spatial skills of lucid dreamers. People who spontaneously experience lucid dreams seem to know how to maneuver in space (not outer!) really well. You may wonder, "what do you mean that having the ability to lucid dream is associated with getting around in space? I mean this quite literally. For instance, we measured people who frequently reported having lucid dreams and those who didn't, and looked at the integrity of their vestibular systems. Before the experiment we weeded out people who get motion sickness or had some kind of obvious vestibular problem. Thus these were all people who had reasonably healthy vestibular systems. We used standard clinical tests of the integrity of the system and found that for those that were not having lucid dreams very often there were marginal problems with their vestibular system. The vestibular system is one of the primary systems we use to orient ourselves in the space around us. How much do we tilt when turning a corner on a bicycle? Are these high heels too high? We also found the same thing when we tested them on a piece of apparatus called a stableometer. This apparatus is like in a circus when clowns balance on a platform resting on a ball. That is frequent lucid dreamers could balance on the platform.
Another aspect of spatial abilities is field independence. Have you ever known someone who no matter wherever they are, they're never lost. Even if there's no big buildings or mountains they seem to know how to find their way around with some sort of internal map. These people are field independent. It is someone who can be relatively independent of their physical environment and can still accurately orient and maneuver themselves in space. This independence of the field we found was very true of spontaneous lucid dreamers. They also are able to manipulate complex spatial objects in their imagination. So, for instance, we asked them to rotate a three dimensional object in imaginary space and then match it to another three dimensional object. They were able to do this significantly more accurately than those for whom consciousness in sleep rarely if ever appeared.
The idea of moving in mental space has some correlates to the ability to move in physical space. Remember when you're in a dream, you're in what feels like a real world with spatial parameters. Although the laws of physics aren't quite the same, you still have to maneuver.
It turns out that the practice of meditation increases performance on these various spatial measures as well as the frequency of lucid dreaming. More over there are some forms of meditation that maintain that consciousness in sleep is a marker of the development of higher states of consciousness. Specifically, if you measure meditators on field independence, they not only score highly field independent but scientists have had to cut the administration time of the test in half in order to get any variability because everybody scores perfectly in the normally allotted time!