Also in this week's column:
- Is it possible to swallow while standing on your head?
- Why do women have smaller feet?
- What is the use of the hymen?
What are zombie behaviours?
Asked by Arthur Wasnegel of New York City
Zombie behaviours? Sounds like the action from B-grade horror movie. Or perhaps what The Stepford Wives get up to. In fact, zombie behaviours refer to routine things we do every day and night without even thinking. It is our unconsciousness acting out.
Most brain activity is unconscious. For example, the regulation of body temperature is one of the jobs of the brain. Yet such an activity is hardly done consciously. Zombie agents cause us to automatically and rapidly perform our zombie behaviors - actions without our conscious mind being aware of the stimulus and physical response.
We do this driving, dancing, and performing many routine actions where we seem to put our conscious mind on hold. Zombie behaviours and the zombie agents that cause them are significant, important to understand, and worthy of scientific study.
According to Christof Koch, a neurobiologist at CalTech in Pasadena, "Zombie agents control your eyes, hands, feet, and posture, and rapidly transduce sensory input into stereotypical motor output. They might even trigger aggressive or sexual behaviour when getting a whiff of the right stuff. All, however, bypass consciousness. This is the zombie in you."
According to Koch, an extreme example of zombie behaviour is sleepwalking. Sleepwalkers can carry out highly complex actions without remembering what they have done. In addition, a sleepwalker can drive a car (as sleepwalkers can and sometimes do).
A zombie behaviour thus occurs within a zombie behaviour - all the more fascinating to Koch. Also, laboratory experiments demonstrate that normal people will respond to scary pictures of snakes and spiders even though they are not consciously aware of them. The zombie behaviour is acting autonomously.
Perhaps most fascinating of all, it has been found that zombie behaviours occur at speeds that far outpace the speeds of conscious reactions to calculate and activate. Being slower, consciousness would therefore seem to be a maladaptive behaviour.
Assuming that any maladaptive behavior would be selected out due to natural selection and thus disappear from the species, an intriguing question emerges in terms of human evolution. Why did consciousness ever evolve at all if the zombie behaviours incorporated into our unconsciousness work so fast and so well?
One possible answer to this comes from Koch along with Francis Crick (the same Francis Crick of DNA double helix discovery fame).
In a 2001 article in NATURE entitled "The Zombie Within", Koch and Crick first speculated that: "It may be because consciousness allows the system to plan future actions, opening up a potentially infinite behavioural repertoire and making explicit memory possible."
Thus, consciousness would appear to be more varied, useful, and adaptable. Koch continues research in this area. In 2004, Koch wrote The Quest for Consciousness: A Neurobiological Approach (Roberts & Company) with a foreword by Crick.
There are many questions surrounding Zombie behaviours and what causes them. Could the zombie in us, primitive though it is, be the source of those rare flashes of insight that appear out of nowhere and from which solutions to problems appear fully formed when we next become conscious? Is this why we solve a problem by "sleeping on it overnight"?
An even more fundamental question (more speculative and fun too) is this: Is our conscious state merely a preparation for our unconscious state? Sleep would be the "normal" human state and being awake would be the preparation for sleep.
Rather changes how we think of about being a human doesn’t it? Maybe the zombie human within us is the more real human? What do you think?
Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to firstname.lastname@example.org