There is another explanation for why not all our dreams are lucid - from the perspective of Developmental Psychology. This holds that when we were foetuses in the womb, we experienced dreams - before we were even aware of the laws of physical reality and logic. These foundational, inuetro dreams may leave impressions on our subconscious, which is a reason why we do not necessarily challenge the reality of the dream and become lucid in all the dreams we experience in later life, even after we attain knowledge as to how our waking life affects our subconscious dream world.
Developmental psychologist Jean Piaget (1896 - 1980) studied children’s dreams and described how children’s acceptance of dreams gradually change from a firm belief of dreams as reality to an awareness that dreams are just a 'story' inside their minds while asleep. This explains why we may begin our sleeping life believing that dreams are real because we are born dreaming. Newborn babies are in the REM sleep state for an average 8 hours per day. REM is the sleep period considered most favorable and fertile for ordinary (non-lucid) dreaming. The dream world is, in many ways, our first and natural world, and the waking world with all of its rules comes later.
Why Do We Accept the Bizarre Reality of Dreams?
This leads me to an interlinked subject - why do we accept our dreams as real while we are dreaming them?
When addressing the altered reality of our dreams, we might look to the research of Sigmund Freud (1856 - 1939) who also believed that dreams were a form of therapy or emotional healing process. In order for us to resolve an inner conflict or obtain wish fulfilment, we must believe in the reality of the dream, and therefore, in the dream state critical thinking and doubt are repressed so that we can fully believe in the dream.
Psychologist Allan Hobson adopts a neurological approach to dreaming, which challenges the idea that dreams have any intrinsic meaning to us. He claims that dreams are simply makeshift and inconsequential narratives, stemming from random brain activity while we sleep. The dreamer makes the best of a bad script, and the result can be nonsensical or bizarre. Due to the fact that areas of the brain that sustain working memory are weakened while we sleep, logic is compromised during dreams. Hence, the dreamer accepts these bizarre situations and transitions in time and space as real.
Theories of Dreaming
Here are some key theories as to why we dream and why we might accept the reality of the dreamstate:
1. We Dream to Practice Responses to Threatening Situations
This is the 'Threat Simulation Theory' propounded by Antti Revonsuo, a Finnish cognitive scientist, who produced evidence to show that our amygdala (the area of the brain responsible for the 'fight-or-flight' response) fires more than normal during REM sleep In REM sleep, the brain functions in a similar way to when it's specifically threatened for survival during waking life. In addition, the part of the brain which practices motor activity (running, fighting) fires increasingly during REM sleep, even though the limbs are still due to muscle atonia/sleep paralysis. Therefore, Revonsuo and other evolutionary theorists argue that in dreams, we are actually rehearsing fight-and-flight responses, even though our limbs are not actually physically moving during sleep. Revonsuo believes that dreams are an evolutionary adaptation - we dream in order to rehearse behaviours of self-defense in the safety of night-time isolation which prepares us for actual waking situations where me may need to utilise these skills for survival. This explains why mammals (specifically cats) - who also experience REM sleep and dreams - have been shown to 'act out' hunting dreams when the part of the brain responsible for REM muscle atonia/sleep paralysis has been deactivated or removed. Hunting is a means of survival for a cat in the wild - and seeing the acting out of physical movements associated with hunting and catching prey allows us to identify the possible content of the cat's dream. As modern humans, our dreams tend to reflect waking life concerns and emotions - we might see these are modern versions of 'threats' to our survival given that the majority of people living in the developed world no longer need to rely on hunting and gathering as a means of survival, nor need to physically protect ourselves from predators.
2. Dreams Create Wisdom
If we remembered every image of our waking lives, it would clog our memories. So, dreams sort through memories, to determine which ones to retain and which to lose. Matt Wilson of the MIT Center for Learning and Memory argues this perspective. In one study, Wilson put rats in mazes during the day, and recorded the patterns of neural activity as the rats negotiated the maze. When he watched the rats enter REM sleep, he saw that the same neuron patterns fired as those which had fired at choice turning points in the maze. In other words, he saw that the rats were dreaming of important junctures in their day. Wilson argues that sleep is the process through which we separate the memories worth encoding in long-term memory from those worth losing. Sleep turns a flood of daily information into what we call 'wisdom' - and we can use this acquired intelligence in real waking decision-making.
3. Dreaming is Like Defragmenting your Brain's Hard Drive
Francis Crick (who co-discovered the structure of DNA) and Graeme Mitchison put forth a famously controversial theory about dreams in 1983 when they wrote that 'we dream in order to forget'. This means that the brain is like a machine which connects its data in certain ways (obsessing, defending or retaining), and that those thinking pathways might not be the most beneficial for us. When we sleep, the brain fires much more randomly and this random scouring for new connections allows us to loosen certain pathways and create new, more advantageous ones. Dreaming is a shuffling of old connections that allows us to keep the important connections and erase the inefficient links - analogous to the defragmentation of a computer's hard drive. Dreams are a reordering of connections to streamline the system.
4. Dreams are a Form of Psychotherapy
For many theorists (including Freud) dream are principally a means by which to confront difficult and surprising emotions and deal with those emotions in a new way. Ernest Hartmann, a doctor at Tufts, focuses on the emotional learning which happens in dreams, developing the theory that dreaming puts our difficult emotions into a visual language. In dreams, we deal with emotional content in a safe place, making connections that we would not make if left to our more critical or defensive waking brains. In this sense, dreaming is like a form of psychotherapy - we think through emotional stuff in a less rational and defensive frame of mind and are able to come up with solutions which may not be available to the conscious mind. Through that process, we also come to accept truths we might otherwise repress.
5. The Absence of Theory
Others - such as Hobson, above - argue that dreams have no meaning at all - they are merely the random firings of an unconscious brain. The mind is still 'functioning' insofar as it's producing images, but there's no conscious sense behind the narrative. Perhaps it's only consciousness itself that wants to see some deep meaning in our brains at all times and therefore our waking brain projects meaning onto the meaningless dream content in order to explain our experience of dreaming.
Normal Non-Lucid Dreams v Lucid Dreams
- A Neuroscientific Comparison
In order to understand the difference between normal dreams and lucid dreams, we can identify neurological differences between these distinct brain states. This sheds some light on why we might accept normal, non-lucid dreams as reality and do not question events in the same way we would if awake or in a lucid dream. A very interesting journal article tackled this precise theme - see Dresler et al, 'Neural Correlates of Dream Lucidity Obtained from Contrasting Lucid versus Non-Lucid REM Sleep: A Combined EEG/fMRI Case Study' (2012) Sleep 35(7), 1017 - 1020. I have summarised the findings of the study, below for the purposes of discussion:
In REM sleep we experience the most vivid and intense forms of dreaming - however, these dreams (when non-lucid) are deficient in reflective thought and metacognition. Instead the internally generated perceptions and emotions experienced during dreaming typically show many cognitive peculiarities, with a bizarre dream narrative full of gaps, delusional thought, and a complete lack of insight into the fact that we are dreaming. These cognitive constraints (i.e. lack of awareness or rationality) are thought to be related to the neural activation patterns associated with REM sleep, particularly deactivation of the dorsolateral prefrontal cortex.
In contrast to normal dreaming, lucid dreaming denotes a rare state of sleep comprising cognitive features of both waking and dreaming. During lucid dreams, subjects become aware of their dreaming state, have full access to memory, and are sometimes able to volitionally control dreamed actions. Although standard polysomnographic criteria of REM sleep are maintained (and REM sleep muscle atonia - commonly referred to as sleep paralysis - prevents overt motor behaviour), lucid dreamers are able to communicate their state by predefined volitional eye movements, clearly discernable in the electrooculogram.
Lucid dreaming can be trained and has been successfully utilized for the treatment of nightmares or post-traumatic stress disorder (PTSD). However, neural changes which accompany dream lucidity, and their role in the amelioration of dream disorders, are not yet well understood. When compared to non-lucid REM sleep, lucid dreaming is associated with increased 40-Hz activity (known as 'gamma brainwaves'), and increased coherence in frontal regions, as has recently been shown by quantitative EEG. Neuroimaging data, delineating the neural correlates of lucid dreaming, have not yet been obtained and analysed. While in a later study Dresler and his colleagues analysed how the skill of lucid dreaming served as a tool for tracing specific motor activity in dreams, the current study aimed to reveal the neural correlates of lucidity per se by contrasting lucid vs non-lucid REM sleep using a combined EEG/fMRI approach.
Neuroimaging studies have shown that human REM sleep is related to characteristic patterns of regional brain activity - during REM sleep, neural activity in the brain stem, thalamus, amygdala, and extrastriate temporo-occipital cortices increases, while the dorsolateral prefrontal cortex and the precuneus show deactivation.
This specific pattern of neural activity has been proposed to reflect the visual hallucinations, emotional intensifications, and cognitive abnormalities typically experienced in dreams. In contrast, lucid dreaming is characterized by a regaining of higher cognitive capabilities, eventually leading to the awareness of the dreaming state.
Recent quantitative EEG data have shown that this 'waking' intellectual clarity is paralleled by neural activations in frontal and frontolateral regions. Likewise, PET data show cognitive control in dreams to be associated with activation of frontal cortex components.
In the current study, Dresler and his colleagues present neuroimaging data showing lucid dreaming to be associated with neural activations in a specific network of cortical regions. In line with the study of Voss et al (see 'Lucid dreaming: a state of consciousness with features of both waking and non-lucid dreaming' (2008) Sleep, 32, 1191 - 200), during lucid dreaming the researchers observed increased activity in the right dorsolateral prefrontal cortex. The dorsolateral prefrontal cortex is thought to underlie a wide range of higher cognitive capacities, as evidenced also by the dysexecutive syndrome seen in patients with lesions in this region. In particular, the right dorsolateral prefrontal cortex was associated with self-focused metacognitive evaluation.
While in normal dreams, working memory is strongly impaired, activation in the dorsolateral prefrontal cortex (in combination with parietal lobules, which were also found to be activated during lucid dreaming) may reflect working memory demands related to task performance in the study. Further, there was observed increased activation in bilateral frontopolar areas, which have been related to the processing of internal states - i.e. the evaluation of one's own thoughts and feelings.
The strongest increase in activation during lucid compared to non-lucid REM sleep was observed in the precuneus - a brain region which has been implicated in self-referential processing, such as first-person perspective and experience of agency/autonomy. While in normal dreams, attention is often hyper-associatively driven by the (pseudo-)external dream scenery, lucid dreaming is - by definition - characterized by a reflection on one's own state of mind.
Interestingly, Dresler et al found activation in the bilateral cuneus and occipitotemporal cortices. These areas are part of the ventral stream of visual processing, which is involved in several aspects of conscious awareness in visual perception. While these activations seem initially puzzling, since non-lucid dreams are also characterized by vivid dream imagery - they are in line with anecdotal reports of lucid dreamers who state that lucidity is associated with an exceptional brightness and visual clarity of the dream scenery.
While lucid dreaming is an intriguing phenomenon in its own regard, it can also serve as a tool for the study of dream disorders - for example, nightmares and PTSD. Neurocognitive models of disturbed dreaming emphasize a hyper-responsivity of the amygdala in nightmare generation, coupled with a failure of medial prefrontal regions to dampen this activation. Lateral prefrontal regions have been shown capable to influence amygdala function through connections to the medial prefrontal cortex. Increased lateral prefrontal activation during lucid dreaming therefore fits well with the therapeutic effects of lucidity training on recurrent nightmares.
If lucid dreaming can also be utilized in the treatment of other dream disorders - for example, terrifying hypnagogic hallucinations, or pathological dream vivification, is an open question that warrants further investigation and research studies. In summary, the study by Dressler et al found that, in line with recent EEG data, lucid dreaming is associated with a reactivation of several areas normally deactivated during REM sleep. This pattern of activity can explain the recovery of reflective cognitive capabilities that are the hallmark of waking life and also lucid dreaming.
