May 22

Consciousness in your dreams?

“A dream is a short-lasting psychosis, and a psychosis is a long-lasting dream.”

-Arthur Schopenhauer

Dreaming has entranced thinkers from the beginning of recorded history, and it’s easy to see why. Both Socrates and Plato agreed that dreaming is a total abandonment of reason. More contemporaneously, no less than Kant and Schopenhauer identified dreaming as a psychotic state, with Freud famously postulating that psychosis comes from dreams intruding on reality, and that dreams are our subconscious running rampant in the absence of the conscious (Freud 1900). While this perhaps is no longer the current thinking, it raises the point that dreaming distances itself from conscious reason. As I hardly need to state, dreams are mysterious states where you can temporarily do anything, see anything, and become anything (limited by your imagination, of course), with the catch that you cede control, and, importantly, consciousness. This article will explore what happens to your consciousness in dreams.

Consciousness in dreams

Simply defined, consciousness is the state of self-awareness, i.e. being aware that you are aware. Some scientists divide consciousness into primary and higher orders, with primary conscious being a basic awareness of the world around you, the present, with higher orders involving self-awareness, metacognition, and awareness of the non-immediate past and future (Hobsen 2009). As defining and discussing consciousness much beyond this becomes a thorny matter, the subject of millennia of debate (and perhaps another Neuwrite article or two), this article will leave it at that.

When you fall asleep, you lose both orders of consciousness/awareness, regaining some semblance of awareness in the dream state, but, importantly, lacking the awareness that it is in fact a dream state and thus, lacking higher order consciousness. So what is happening in the brain during this? When you first start sleeping, you enter non-REM sleep, which is characterized by a global silencing of brain activity, and few dreams. You then, generally, enter REM sleep, which is characterized by activity in most brain regions near waking levels (Hobsen 2009), although areas that control movement and the frontal lobe are notably not as active. During REM, dreams are reported to be more frequent and more vivid, though, granted, this relies entirely on self-reporting, and could be based on that fact that you are more likely to remember a dream during REM. Regardless, the activation of most of the brain, particularly sensory and emotional areas seems consistent with the vivid events and emotions one experiences in a dream. Generally, the only areas that are consistently inactive, compared to waking, are the frontal lobe and areas that are responsible for generating movement (Hobson 2009), although patients with a lesioned frontal lobe reporting an absence of dreams (Epstein 1977).

Interestingly, a group of scientists found via fMRI that dreaming and  jazz improvisation have similar patterns. Notably, the dorsolateral prefrontal cortex (DLPFC, a region unique to higher order primates implicated in high-order executive function, which is thought to be highly related to consciousness) is deactivated in both, suggesting a link between creativity and the loss of consciousness. The authors state “an  attenuated  DLPFC  no  longer regulates  the  contents  of  consciousness, allowing  unfiltered,  unconscious, or random thoughts and sensations to emerge”, which the study’s authors suggest contribute to the creativity and flow of musical improvisation (Limb and Braun 2008). Similarly, this state is reflected in the creativity in the unconsciousness of dreams. To me this lack of executive control during improvisation makes some sense; when I get really into playing music, I’m not necessarily thinking about what to play next, it just sort of happens, essentially unconsciously. This has interesting implications about the dream state, perhaps hinting that it is this lack of executive control allows for dreams’ creativity and lack of agency and self-awareness.

Inducing lucidity

What if you could have higher order consciousness during sleep? Welcome to lucid dreaming. A lucid dream is one in which the dreamer becomes aware that they are dreaming and is consequently able to control their dream (there is some debate whether merely being aware, without the ability to control the dream is ‘lucid dreaming’, but this is mostly semantics). It seems to happen frequently to a minority of the population, although half of the population has experienced a lucid dream at least once, with about 20% of people lucid dreaming at least once a month (Stumbys et al 2012). Interestingly, it is more prevalent in children. Not surprisingly, brain imaging studies of lucid dreamers have found that “lucid dreaming was associated with a reactivation of areas which are normally deactivated during REM sleep” (Dresler et al 2012), but are activated in waking life.  Through using a combination of EEG and fMRI methods, multiple studies have shown that the frontal lobe is activated during lucid dreams, something which isn’t seen in normal dreams, with the prefrontal and dorsolateral prefrontal cortices (the so-called executive areas discussed prior) particularly active (Voss et al 2009, Dresler et al 2009).

While there are many ways in which people try to induce lucid dreams, there are only a handful which actually have been demonstrated to work (Stumbrys et al 2012). The most prevalent of these is MILD, in which you rehearse a dream before falling asleep, imagining yourself as becoming lucid in the dream and focusing on the fact that this is a dream. The hope is that one will then fall asleep, and have that dream, then remember that this is the dream that you rehearsed, and is thus a dream. Another way is called Tholey’s combined technique (after the inventor of the method), which combines several techniques: autosuggestion (where you tell yourself that you will lucid dream before falling asleep), intention (imagining oneself lucid dreaming before falling asleep), and reality testing (constantly asking yourself through the day whether you are dreaming/testing reality). Neither technique seems to have great success in prompting lucid dreams in the majority of subjects, but both have been shown in several studies to work better than chance, inducing lucidity in some subjects (Stumbrys et al 2012). Of course, once one has lucid dreamed, it is easier to lucid dream again, particularly with the above techniques.

Interestingly, Stephen LaBerge, a prominent lucid dream researcher filed a patent in 2004 for a drug that induced lucid dreams. By dosing patients with Donepezil, which prevents acetylcholine (ACh, a neurotransmitter that increases arousal and responsiveness, among other things) from being degraded, he induced lucid dreams in 9 of 10 subjects (compared to 1:10 for placebo). Of course, this comes with the unhappy side effects of insomnia, nausea and occasional sleep paralysis, and some of this effect may be due to this increased insomnia. While a scientific study has yet to be published on this phenomena, its results do raise an interesting point on the role of brain activity in inducing consciousness. Perhaps, by making ACh more effective, the part of the brain responsible for higher order consciousness (if one exists) becomes activated.

A study that came out in this month’s issue of Nature Neuroscience posits an even more promising way to induce lucid dreaming in naive subjects. By electrically stimulating the frontal lobe at a specific, 40Hz, frequency, they were able to reliably induce a higher order consciousness during dreams in subjects that never experienced this before (Voss et al 2014). This was the same region and frequency which was previously found to be present during a lucid dream (Voss et al 2009). A prior study showed that when the frontal lobe is stimulated in a non-specific manner (not at 40Hz), there is a weak induction of lucid dreaming (Stumbrys et al 2013) only in those who had previous lucid dreaming experience, and the current study confirmed that other frequencies of stimulation elicited lucid dreaming very minimally or not at all (Voss et al 2014).

So what does this tell us about consciousness in dreams?

The ways in which lucid dreaming can be induced are greatly telling of the nature of consciousness in dreaming. The ability to behaviorally induce consciousness through what essentially amounts to rehearsal and awareness demonstrates that we can change what our brain is doing purely cognitively. In reinforcing a certain network, in this case a higher order self-awareness, we can unconsciously activate this network. Of course, it is also telling that this is extremely hard to do (with all studies reporting a relatively low percentage of success over control groups), and is much more prevalent in those who already have such networks and schemas in place, that is, prior lucid dreamers. The recent work in inducing consciousness through stimulating the frontal lobe in a highly specific manner seems to show that there is indeed a discrete event happening to activate this higher-order awareness, a particular pattern of activity. This is quite promising in that it hints at how consciousness, in a limited sense, happens in the brain, and could potentially lead to further insight into what exactly this stimulation does to promote this state.

While it is tempting to extrapolate these results into saying something broadly about the nature of higher order consciousness and how it relates to the frontal lobe, much more work must be done. Patients with frontal lobe lesions (i.e. entirely no frontal lobe) still have consciousness (Epstein 1977, see also the famous case of Phineas Gage), so it’s not as if the seat of consciousness rests entirely in the frontal lobe. A more likely scenario is that consciousness is distributed, with the frontal lobe perhaps acting as a sort of control or switch that can engage and connect these distributed systems responsible for consciousness.

References  

Dresler M, Wehrle R, Spoormaker VI, Koch SP, Holsboer F, Steiger A, Obrig H, Sämann PG, Czisch M. Neural correlates of dream lucidity obtained from contrasting lucid versus non-lucid REM sleep: a combined EEG/fMRI case study. Sleep. 2012 Jul 1;35(7):1017-20. doi: 10.5665/sleep.1974.

Epstein AW. Dream formation during an epileptic seizure: implications for the study of the “unconscious”. J Am Acad Psychoanal. 1977 Jan;5(1):43-9.

Freud S The interpretation of dreams Encyclopedia Britannica, London (1900)

Limb, C. H., and Braun, A. R. (2008). Neural substrates of spontaneous musical performance: an fMRI study of jazz improvisation. PLoS ONE 3(2), 1–9.

Hobson JA. REM sleep and dreaming: towards a theory of protoconsciousness. Nat Rev Neurosci. 2009 Nov;10(11):803-13. doi: 10.1038/nrn2716. Epub 2009 Oct 1.

Stumbrys, T., Erlacher, D., Schädlich, M., & Schredl, M. (2012). Induction of lucid dreams: A systematic review of evidence.Consciousness and Cognition, 21(3), 1456-1475

Stumbrys T, Erlacher D, Schredl M. Testing the involvement of the prefrontal cortex in lucid dreaming: a tDCS study. Conscious Cogn. 2013 Dec;22(4):1214-22. doi: 10.1016/j.concog.2013.08.005. Epub 2013 Sep 8.

Voss U, Holzmann R, Tuin I, Hobson JA.  Lucid dreaming: a state of consciousness with features of both waking and non-lucid dreaming. Sleep. 2009 Sep;32(9):1191-200.

Voss U, Holzmann R, Hobson A, Paulus W, Koppehele-Gossel J, Klimke A, Nitsche MA. Induction of self awareness in dreams through frontal low current stimulation of gamma activity. Nat Neurosci. 2014 May 11. doi: 10.1038/nn.3719

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