All too often, popular culture takes undue liberties with matters of the mind – but how skewed is our idea of how the brain works? Do fact and fiction always sing from the same hymn sheet?
We should start with the basics – what are brainwaves? Your brain is essentially a great mass of wires and circuits. When you think, current flows through these ‘wires’ (cells known as neurones) from one part of the brain to another. When current flows in this way, electrical signals resulting from these processes can be detected on the surface of the brain, through the skull, using electrodes. This results in a picture (or ‘waveform’) on a monitor called an electroencephalogram (EEG), which is similar to an ECG.
Obviously, the brain is doing multiple things at any given time, and so the resulting information is a bit jumbled. Once this jumbled signal is sorted out, the result is a short and fast waveform, called a beta wave. When we go to sleep, this picture changes entirely. Instead of a busy metropolis, the brain becomes a tranquil sea – devoid of the activity that characterises the waking state. The brain shuts down and becomes desensitised to all but the most intense external stimuli. Accompanying this is a decrease in the amount of detectible electrical activity. As you fall asleep, your brain descends through a continuum of brain waves which are much longer and slower than beta waves, ranging from alpha waves (most active) through to theta and then delta waves (least active).
In practice, a person’s state of alertness is usually measured simply by their ability to respond to pain and touch. However, the presence and type of brain waves detected by an EEG can be used by medics to determine the consciousness of a patient, and to investigate brain activity where the underlying neurological problem may not be so apparent. The relevant terminology can be employed with wild abandon in certain narratives, but may also be used quite accurately in some television programmes, such as House and ER.
EEGs are also exploited in science fiction exploring the stranger side of neuroscience such as telepathy and mind control (Star Trek’s Vulcans and X-Men’s Jean Grey being prime examples) – where a subject may be (arbitrarily) said to be exhibiting “strange brain waves.” In reality, the brain simply lacks a natural means to directly send electrical signals to, and interact with, another individual. However, the ability to communicate with others and with machines by thought alone might not be as fantastical as we may think. Many futurists believe technology holds the key to unlocking such potential, and researchers in Switzerland have already developed a prototype wheelchair capable of being controlled entirely by the mind for patients suffering from total body paralysis.
Returning to sleep; every few hours during the night, your brain will go into an extremely deep sleep, called R.E.M. (rapid eye movement) sleep. This lasts about forty-five minutes, and is when you dream. At this point, your brain ramps back up to highly active beta-like waves. This is because a dream is quite like being awake, except you are experiencing an alternate dream-reality based on memories and past experiences.
However, everything seems real at the time, and you’re processing a vast amount of simulated sensory information just as though you were awake. You are even electing to make movements based on these stimuli – the only thing stopping you acting out these movements is an automatic, body-wide paralysis during the dream.
When this safety mechanism fails, a person will talk in their sleep or even sleep walk. This is exploited in narratives where people may reveal their darkest secrets in the middle of the night – an idea that is not unrealistic, as it is quite possible for people to coherently form words or even complete sentences while dreaming.
The concept of dreaming is the also the crux of narratives which explore ideas of virtual reality such as The Matrix and Inception, which exploit the ability of the brain to process sensory information, despite it not actually existing. Furthermore, the brain’s powerful capacity to imagine and interact with artificial worlds depicted in video games might be seen as an extension of the ability to dream.
Finally, a narrative gambit so overused that it has become inextricably associated with television and film: the soap opera coma. A comatose state is actually defined as a period consisting for more than six hours in which a person cannot be awakened, even by strong stimuli such as pain. This is, in essence, abnormally deep sleep and is the body’s response to some form of extensive damage – the idea being to restrict all non-essential bodily activities to allow resources to be used only to heal the individual and prevent further damage.
A study was carried out and published in 2006 to determine how accurately comas are depicted on the silver screen. It found that characters often recover instantly, with full consciousness. This is far from the reality, where patients can go through days or weeks of incomplete and transient consciousness. Perhaps a more obvious error is that characters often awaken with tanned skin or even fully toned muscles, which is unlikely due to the decay muscles undergo during extended periods of disuse. Evidently, work remains to be done where science meets fiction.