The idea that dreaming may represent a protoconscious state was introduced by J. Allan Hobson in November 2009 in the journal Nature Reviews/Neuroscience.
Hobson believes that REM sleep, the state in which helps we are most likely to dream, helps us to develop the form of consciousness that we experience when we are awake. The development of consciousness and the ability to learn is aided by the creation of a virtual world during REM sleep.
Previously, along with Robert W. McCarley, Hobson developed the Activation Synthesis theory of dreams, which says that dreams are caused by random stimuli created by the brainstem.
Dreams and Consciousness
Usually, we think of ourselves as being conscious when we awake and unconscious when we are asleep (whether we are dreaming or not).
Hobson says that, in fact, when we dream we are in an alternate state of consciousness.
Hobson calls the state of consciousness that we experience when we dream primary consciousness and the state that we experience when we are awake secondary consciousness.
When you have a lucid dream, you are in a state that combines qualities of both primary and secondary consciousness.
Primary Consciousness
Primary consciousness consists of simple awareness. It includes the ability to perceive things and the ability to experience emotions.
Most mammals have primary consciousness.
When you dream non-lucidly, you experience primary consciousness – you have perception and emotion, and can organize your thoughts into a story-like structure.
Primary consciousness is an important foundation for the development of secondary consciousness.
Secondary Consciousness
Secondary consciousness includes abstract thinking, self-reflection, and metacognition – knowing that you know something. When you experience secondary consciousness, you are aware of your state of consciousness as well as of the external world.
To experience this type of consciousness, you must have the ability to use language. Therefore, as far as we know, only human beings have secondary consciousness.
This is the type of consciousness that you experience when you are awake.
When you dream – if you aren’t having a lucid dream – you do not experience secondary consciousness. You aren’t aware of your state of consciousness; you don’t know that you are dreaming. You aren’t aware of the external world; you don’t know that you’re really lying in bed.
Three Brains States and the AIM Model
Your brain is normally in one of three different states. Two of these occur when you are asleep. These are REM sleep and NREM sleep. (REM stands for “rapid eye movement” and NREM for “non-rapid eye movement.”)
The third brain state is the state of waking consciousness – when you are aware of the external world, and you are aware that you are aware.
Hobson has created a model which compares the differences between these brain states in terms of
- Activation
- Input-Output Gating, and
- Modulation.
He calls this model the AIM Model.
Activation
Large areas of the brain are active during both waking and REM sleep.
During NREM sleep, the brain is relatively inactive.
Thus, when you are asleep the brain alternates between periods of brain activity that occur with REM sleep and periods of inactivity that occur during NREM sleep.
Input-Output Gating
The reason that being awake and having a dream are different experiences for you, even though both waking and REM sleep involve high levels of brain activation, has to do with the way your senses experience things in these two different states.
During REM sleep, your brain becomes “disconnected” from the external world. Your external senses are diminished, as is your ability to interact with the outside world – your muscles become paralyzed. You become internally-focused.
Modulation
Modulation refers to the way that your brain releases neurochemicals that influence how it works.
When you are awake, your brain releases the neurochemicals acetylcholine, dopamine, histamine, noradrenaline and serotonin.
When you are in REM sleep, your brain releases dopamine and acetylcholine, but it doesn’t release noradrenaline, serotonin or histamine.
The fact that your brain continues to release dopamine during REM sleep, but doesn’t release all five of the neurochemicals that are released when you are awake, could explain why dreams are so bizarre – with visual hallucinations and strange and illogical happenings.
Dopamine production is thought to have a role in mental illness, particularly schizophrenia.
Many dream theorists, including Freud and Jung, as well as the modern sleep researcher William Dement, have commented on the similarities between dreams and insanity.
Previously, Mark Solms theorized about the relationship of dopamine to dreaming.
When it comes to modulation, NREM sleep is an in-between state. During NREM sleep, your brain produce all five neurochemicals, but their production takes place at a slower pace than when you are awake.
Development of REM Sleep
REM sleep evolved relatively recently. It exists only in mammals and birds.
In the early stages of life, birds and mammals experience a huge amount of REM sleep.
The greatest amount of REM sleep in humans takes place before birth, during the third trimester of the mother’s pregnancy.
In human fetuses, REM sleep, in which the brain is highly active, alternates with periods in which the brain is inactive (NREM sleep).
Waking consciousness, the third brain state, develops later on in life.
REM sleep and waking consciousness are similar in that they both involve high levels of brain activity.
As our lives go on, we spend more time awake and our cognitive ability increases. The amount of REM sleep we experience decreases. That is, the amount of primary consciousness lessens and the amount of secondary consciousness grows.
REM Sleep and Dreams
Although we begin experiencing REM sleep very early in our lives, we don’t have the story-like experiences that we call “dreams” until we are much older. In order to have dreams, we need the capability to create organized narratives. Children probably don’t have real dreams until they are between five and eight years old.
Mark Solms and David Foulkes have both performed research which shows that REM sleep and dreams are not the same thing – sometimes people have dreamlike experiences when they are not in REM sleep.
Throughout childhood, the ability to use and understand language increases, as does the amount of true dreaming (distinct from REM sleep) and the tendency to talk about dreams.
REM Sleep and Protoconsciousness
REM sleep and waking consciousness are both active brain states. Therefore, Hobson believes that REM sleep could be a way of preparing the brain to operate in the waking state. In other words, REM sleep is a protoconscious state.
Brain activation during REM sleep helps to build the circuits that are necessary for developing and maintaining higher brain function, including consciousness. The visual imagery that you see in your dreams helps stimulate your visual system, so that it can develop properly.
Throughout your life, you continue to learn things and your brains continue to grow and develop. Therefore, you continue to have REM sleep as long as you live.
Virtual Reality During REM Sleep
When you are awake, your brain has access to information about the external world. During sleep, you no longer receive input from the external world and have to simulate it in your dreams.
Hobson believes that, during REM sleep, the developing brain has a built-in model of external space and time. This model is based on predictions of what the brain thinks the world should be like; it is continually being adjusted to conform to real experiences of the world.
In your dreams you create a virtual model of yourself – a “protoself” – that moves through a virtual world (the model of the external world that your brain has created). This protoself experiences strong emotion.
The idea that your brain recognizes a “virtual you” – that represents the “real you” – helps to explain what causes out of body experiences.
At first, REM sleep and the virtual world that it creates is not associated with conscious awareness. We are only able to integrate our experience of REM sleep and become aware of it during childhood.
Hobson’s belief that REM sleep is a way of training your brain to function in the real world is reminiscent of Antti Revonsuo’s evolutionary theory of dreams, which says that we evolved the ability to dream to learn how to cope with dangers in the real world.
Lucid Dreaming
Hobson says that lucid dreaming is a brain state that lies somewhere between REM sleep and waking.
Electroencephalograms (EEGs) show that when you have a lucid dream, areas of the brain that are usually active when you are awake, but not when you are in REM sleep – areas that are associated with secondary consciousness – become active. However, they do not become active enough to wake you up.