Paranormality: Why we see what isn't there

by Richard Wiseman

  In short, over a hundred years of scientific soul searching has ended in failure. Despite Baraduc’s attempts to photograph the spirits of his dead son and wife, MacDougall weighing the dying and Watters slaughtering several grasshoppers, the evidence didn’t stack up. As a result, the researchers changed tack and focused their attention on the information provided by those who claimed to have left their bodies. The best anecdotal case studies turned out to be a tad unreliable, and experiments involving hundreds of OBEers attempting to identify thousands of hidden targets failed to yield convincing results.

  After all of this, it might appear that out of the body experiences have nothing to offer the curious mind. However, subsequent work has adopted a very different approach to the problem and, in doing so, both solved the mystery and provided an important insight into the innermost workings of your brain.

  There is an old joke about a man who is trying to track down a particular room in a University Philosophy Department. He becomes lost and eventually comes across a map of the building. On the map he sees a large red arrow pointing to a particular corridor, and on the arrow it says ‘Are you here?’ It’s not a bad gag. But more importantly it raises an important issue – how do you know where you are? Or, to put it in slightly more philosophical language – why do you think that you are inside your own body?

  It many ways, it seems like an odd question. After all, we seem to be inside our bodies and that is that. However, the question has hidden depths. Perhaps the greatest insights have come from a ground-breaking experiment that you can recreate in your own home using just a table, a large coffee-table book, a towel, a rubber hand and an open-minded friend.14

  Start by sitting at the table and placing both of your arms on the tabletop. Next, move your right arm about six inches to the right and place the rubber hand where your right hand used to be (this is assuming that the dummy hand is a right hand – if not, use your left hand during the demonstration).

  The set-up for the first part of the dummy hand experiment.

  Now stand the book vertically on the tabletop between your right arm and the rubber hand, ensuring that it prevents you from seeing your right arm. Then use the towel to cover the space between your right hand and the rubber hand (see photograph below).

  The dummy hand experiment in action. It is possible to appreciate the psychological impact of the experience by looking at the facial expression of the person in the photograph.

  Finally, ask your friend to sit opposite you, extend their fingers and use them to stroke both your right hand and the rubber hand in the same place at the same time. After about a minute or so of stroking you will start to feel that the rubber hand is actually part of you. This feeling has interesting consequences for your real, but hidden, hand. Researchers have monitored the skin temperature of people’s hands during the study and discovered that when they believe that the rubber hand is part of them, their hidden hand becomes about half a degree colder – it is as if the brain is cutting off the blood supply to the unseen hand once it believes that it is no longer part of the body.15

  It is a powerful illusion. In a similar series of studies, conducted by Vilayanur Ramachandran and described in his book Phantoms in the Brain, people were asked to place their left hand below a table, and an experimenter then stroked the hidden hand and the tabletop simultaneously.16 Once again, their sense of self shifted, with about 50 per cent of people feeling as if the wooden tabletop had become part of them.

  To explain what’s going on here, let’s use a simple analogy. Imagine walking around in a new city and suddenly realizing that you are lost. The only way forward is to go hunting for a signpost. Similarly, when your brain is trying to decide where ‘you’ are it has to rely on the equivalent of signposts, namely, information from your senses.

  Most of the time this works really well. Your brain might, for example, see your hand and feel pressure from your fingertip, and so correctly assume that ‘you’ are in your arm. However, in the same way that people sometimes mess around with signposts and point them in the wrong direction, so once in a while your brain will mess up. The rubber hand experiment is one of those situations. During the study, your brain ‘feels’ your left hand being stroked, ‘sees’ a dummy hand or wooden table being subjected to simultaneous stroking, concludes that ‘you’ must therefore be located in the dummy hand or table, and constructs a sense of self that is consistent with this idea. In short, the sense of where you are is not hard-wired into your brain. Instead, it is the result of your brain constantly using information from your senses to come up with a sensible guess. Because of this, the sense of ‘you’ being inside your body is subject to change at a moment’s notice.

  Ramachandran’s work has important practical, as well as theoretical, implications. The majority of people who have had an arm or leg amputated often continue to feel excruciating levels of pain from their phantom limb. Ramachandran wondered whether this pain was due, in part, to their brains becoming disoriented because they were continuing to send signals to move the missing limb but then not seeing the expected movement. To test his theory, Ramachandran and his colleagues ran an unusual experiment with a group of amputees who had lost an arm.17 The research team built a two-foot-square cardboard box that was open on the top and front. They then placed a vertical mirror along the middle of the box, thus separating it into two compartments. Each participant was asked to place their arm into one of the compartments, and then orient themselves so that they could see a reflection of their arm in the mirror. From the amputee’s perspective it appeared as if they were seeing both their actual, and missing, arm. The amputee was then asked to carry out a simple movement with both of their hands at the same time, such as clenching their fists or wriggling their fingers. In short, Ramachandran’s box created the illusion of movement in their missing limb. Amazingly, the majority of the participants reported a reduction in the pain associated with their phantom limb, with some of them even asking if they could take the box home with them.

  It is one thing to convince people that part of them inhabits a dummy hand or tabletop, but is it possible to use the same idea to move a person out of their entire body? Neuroscientist Bigna Lenggenhager, from the École Polytechnique Fédérale de Lausanne in Switzerland, decided to investigate.18

  If you were to take part in one of Lenggenhager’s studies you would be taken into her laboratory, asked to stand in the centre of the room and fitted with a pair of virtual reality goggles. A researcher would then place a camera a few feet behind you and feed the output into your goggles, causing you to see an image of your own back standing a few feet in front of you. Next an animated stick would appear on the image in front of you and slowly stroke your virtual back. At the same time the researchers would sneak up behind the real you and slowly stroke your back with a highlighter pen, being careful to ensure that the actual stroking matched the virtual stroking. The experimental set-up is identical to the dummy hand study, but with the ‘virtual you’ taking the place of the dummy hand and a highlighter pen replacing your friend’s hand. In the same way that stroking the dummy hand produced the strange sensation that part of you inhabited the hand, so Lenggenhager’s set-up resulted in people feeling as if their entire body was actually standing a few feet in front of themselves.

  The dummy hand and virtual reality experiments demonstrate that the everyday feeling of being inside your body is constructed by the brain from sensory information. Alter that information and it is relatively easy to get people to feel as if they are outside of their bodies. Of course, people don’t have access to rubber hands and aren’t wired into virtual reality systems when they have out-of-body experiences. However, many researchers now think that this strangely counter-intuitive idea is essential to understanding the nature of these episodes.

  MIRROR, MIRROR ON THE WALL

  Neuroscientist Vilayanur Ramachandran and his colleagues have created a simple way of replicating Lenggenhager's experiment without the need for a complica
ted and expensive virtual reality system.19 In fact, you just need two large mirrors and your finger. Arrange the two mirrors so that they are facing one another and a few feet apart. Next, angle one of the mirrors so that when you look into one mirror you see the reflection of the back of your head (see photograph). Finally, gently stroke your cheek with your finger and look at the image in the mirror.

  Set-up for the mirror experiment.

  This rather unusual set-up replicates the illusion created by Lenggenhager's virtual reality system. Your brain 'feels' your cheek being stroked, 'sees' a person standing in front of you being subjected to simultaneous stroking, concludes that 'you' must therefore be standing there, and constructs a sense of self that is consistent with this idea.

  When he took part in the demonstration, Ramachandran felt as if he was touching an alien or android body that was outside his own body. Many of his colleagues felt similar sensations, with some of them reporting that they wanted to say 'hello' to the person in the mirror.

  At the start of this book I described how seeing psychologist Sue Blackmore on television made me realize how studying the supernatural could reveal important insights into our brains, behaviour and beliefs. Blackmore has investigated many aspects of the paranormal over the years, but much of her work has focused on the secret science behind out-of-body experiences.

  Witchcraft, LSD and Tarot Cards

  Sue Blackmore’s interest in the paranormal dates back to 1970 when she was a student at Oxford University and had a dramatic out-of-body experience. After several hours experimenting with a Ouija board and then relaxing with some marijuana, Sue felt herself rise out of her body, float up to the ceiling, fly across England, travel over the Atlantic, and hover around New York. Eventually she travelled back to Oxford, entered her body through her neck and finally expanded to fill the entire universe. Other than that it was a quiet night.

  Upon her return to reality, Sue became fascinated with weird experiences, trained as a white witch, and eventually decided to devote herself to parapsychology. She was awarded a doctorate for work examining whether children have telepathic powers (they didn’t), went on several LSD trips to see if they would improve her psychic ability (they didn’t), and learned to read Tarot to discover if the cards could predict the future (they didn’t). After 25 years of such disappointing results Sue finally gave up the ghost and became a sceptic. For many years she examined the psychology of paranormal experiences and beliefs, trying to figure out why people experienced seemingly supernatural sensations and bought into such strange stuff. Most recently she has turned her attention to the mystery of consciousness, focusing on the ways in which the brain creates a sense of self (although, rather disappointingly, the ‘Who Am I’ tab on her website delivers a straight biography).

  One of Blackmore’s early investigations tackled a question that comes up frequently when I speak about the paranormal – why do identical twins often appear to have a strange psychic bond with one another? Many proponents of psychic ability believe that this odd bond is due to telepathy. In contrast, sceptics argue that twins will often think in very similar ways because they have been raised in the same environment and have the same genetic makeup, and that such similarity will cause to them to make the same decisions and thus appear to read each other’s minds.

  To help settle the issue, Blackmore brought together six sets of twins and six pairs of siblings, and conducted a two-part experiment.20 The first part was a straightforward test of telepathy. One member of each pair played the role of the ‘sender’ while the other was the ‘receiver’. The sender was presented with various randomly selected stimuli (such as a number between one and ten, an object, or a photograph), and was asked to psychically transmit the information to the receiver. No evidence of telepathy emerged from either the twins or the siblings.

  In the second part of the experiment, Blackmore asked the senders to transmit the first number that came into their mind, make any drawing that appealed to them, and choose which of four photographs to send. The results suddenly changed. As predicted by the ‘twin telepathy is due to similarity’ hypothesis, there was a sudden surge in the twins’ performance. For example, when asked to think of a number between one and ten, 20 per cent of the trials involving twins produced the same number compared to just 5 per cent of those with the siblings. For the drawings, the twins again scored well, exhibiting a 21 per cent success rate compared to the siblings’ 8 per cent.

  In short, the evidence indicates that twin telepathy is due to the highly similar ways in which they think and behave, and not extra-sensory perception.

  Interview with Sue Blackmore

  www.richardwiseman.com/paranormality/SueBlackmore.html

  However, Blackmore is perhaps best known in sceptical circles for her work explaining out-of-body experiences. She took as her starting point the notion that the feeling of being located inside your body is an illusion created by your brain on the basis of incoming sensory information. Then, in the same way that a rather weird set of circumstances involving a dummy hand or a virtual reality system can cause people to believe that they are elsewhere, Blackmore wondered whether an equally strange set of circumstances might cause people to think that they had floated away from their bodies. Sue focused her attention on two elements that were central to most OBEs.

  The first principle can be illustrated with the help of the image over the page.

  Fix your eyes on the black dot in the centre of the image and stare at it. Providing that you are able to keep your eyes and head relatively still you will find that after about 30 seconds or so the grey area around the dot will slowly fade away. Move your head or eyes and it will jump right back again. What is going on here? It is all about a phenomenon referred to as ‘sensory habituation’. Present someone with a constant sound, image, or smell and something very peculiar happens. They slowly get more and more used to it, until eventually it vanishes from their awareness. For example, if you walk into a room that smells of freshly ground coffee, you quickly detect the rather pleasant aroma. However, stay in the room for a few minutes, and the smell will seem to disappear. In fact, the only way to re-awaken it is to walk out of the room and back in again. In the case of the illustration above your eyes slowly became blind to the grey area because it was unchanging. This exact same concept can result in the so-called ‘hedonistic treadmill’, with people quickly getting used to their new house or car, and feeling the need to buy an even bigger house or better car.

  Blackmore speculated that this process was also central to OBEs. People tend to experience OBEs when they are in situations in which their brains are receiving a small amount of unchanging information from the senses. They are often robbed of any visual information because they have their eyes shut or are in the dark. In addition, they usually don’t have any tactile information because they are lying in bed, relaxing in the bath, or are on certain drugs. Under these circumstances the brain quickly becomes ‘blind’ to the small amount of information that is coming in, and so struggles to produce a coherent image of where ‘you’ are.

  Like nature, brains abhor a vacuum, and so start to generate imagery about where they are and what they are doing. That is part of the reason why people are more likely to have images flowing through their mind when they shut their eyes, are in the dark or take drugs. Blackmore hypothesized that certain types of people would naturally find it easy to imagine what the world looks like when you float out of your body, and also become so absorbed in their imagery that they confuse imagination for reality, and that these individuals that would be especially likely to experience OBEs.

  To test her theory Blackmore carried out several experiments.21 In fact, you have already taken part in a version of them. A few pages ago I asked you to imagine yourself being about six feet above where you actually are, and rate the clarity of your imagery and the ease with which you switched from one perspective to another. Sue presented this task to two groups of people – those that had experienced an o
ut-of-body experience and those that had not – and obtained very different results. Those that had previously experienced floating away from themselves tended to report much more vivid images and found it much easier to switch between the two perspectives.

  Blackmore also speculated that people who reported OBEs would tend to become absorbed in their experiences, so that they found it difficult to separate fact from fantasy. I also asked you to rate the degree to which six statements described you. Five of them are the types of items that you find on standard questionnaires designed to measure the degree to which you become absorbed in your experiences (I added the item about the stoats working too hard for fun). People who obtain high scores on absorption questionnaires tend to lose track of time when they watch films and television programmes, become confused about whether they have actually carried out an action or simply imagined it, and are more easily hypnotized (in the case of the five questions presented at the start of this chapter a total of 20 or more would constitute a high score). In contrast, lower scorers are more down-to-earth, practical and rarely confuse their imagination with reality (a low score would be ten or less). Blackmore’s studies involved asking OBEers and non-OBEers to complete absorption questionnaires: the OBEers consistently obtained much higher scores.