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Common misperceptions |
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Misperception and hallucinations Misperception is misinterpreting something seen, heard, felt or otherwise sensed. Hallucinations, by contrast, originate inside your brain, so they don't require any 'something' in the real world (a sensory stimulus). Between them, misperceptions and hallucinations probably account for a great many reports of apparent paranormal phenomena.
Looking for misperception and hallucination Hallucination is more difficult than misperception to detect. With no 'sensory stimulus' to look for, detecting hallucination requires examining what was happening to the witness when they experienced the apparent paranormal phenomenon. If they were on the verge of sleep at the time, for instance, you might suspect hypnagogic or hypnopompic hallucination. If they felt paralysed then it might be sleep paralysis. Many people experience one or two episodes of sleep paralysis in their lives. Other causes of hallucination include sensory deprivation and absorption. Some other types of hallucination may be caused by medical conditions (like epilepsy) or by taking certain drugs, so you could check witnesses's medical history (see also mindsight). A small number of hallucinations may be induced by such things as certain magnetic fields. With misperception there is something outside the witness to look for - the sensory stimulus! It would be worth trying to recreate the situation of the original experience, at precisely the same location, to see if the object is obvious. It would be very useful if you could reproduce the lighting conditions too, if relevant, as many misperceptions occur in poor light. If you're lucky, you too may experience the same misperception. Sometimes, though, the cause of a misperception may have gone by the time of the investigation. Misperception As optical illusions illustrate, our brains can easily be fooled. Misperceptions are caused by ambiguous, insufficient or conflicting sensory information reaching our brains.
In all such cases, it seems our brains 'resolve' such problems BEFORE presenting sensory information to our consciousness. Thus we are presented with a seamless experience which may, sometimes, not reflect the real world. In order to understand misperceptions, we must first understand normal perception. Details of the process are still being unraveled by science but we know some relevant things already. The picture in your head - visual misperception The most 'acute' of your senses is vision. It is 'acute' because it is the one we rely on the most to form our picture of reality. When our senses receive conflicting information, vision is the one that wins the tussle. Vision also provides more information than any of the other senses, measuring not only the wavelength and amplitude of light (equating to colour and brightness) but also the spatial layout of light sources in three dimensions. By comparison, only frequency and amplitude are measured in hearing. Consider the 'picture in your head' - that crisp, colourful movie of the world behind your eyes that most people assume is reality. In fact, it is a moving image stored and played in your brain. The whole image is not fed continuously by your eyes but instead it receives brief detailed updates of small parts of the view in front of you. The bits of the image not currently being updated are slightly out of date, being the result of previous updates. The reason is that detailed views can only be obtained from a small bit of your retina, called the fovea. Your eye performs constant jerky movements, called saccades, to point the fovea at the most interesting parts of a scene. The fovea then 'fixates' on a small area while passing information to the brain. During the actual eye movements, little or no information goes to the brain. We generally perform about three saccades a second, each lasting 20 to 200 microseconds. For the remaining time we are fixating on a relatively small area of the scene ahead. So how is the 'picture in your head' maintained? Recent scientific research suggests that it is partly from updates, partly from short term memory (what was there at the last fixation) and partly from visual long term visual memories. This last bit is particularly interesting from the point of view of misperception. If you see an 'ambiguous stimulus' (something seen that your brain does not immediately recognise from memory or where there are conflicting signals from other senses), your brain needs to make a quick decision. It tries to maintain a picture that 'makes sense', so sometimes it may substitute the ambiguous visual information with something from its long term memory. This happens before the 'picture in your head' is updated, so the substitution is not noticed and feels perfectly real to you, the witness. Consider, for instance, if you saw a shadow in a dark room, your brain might not have sufficient information to work out what it is. So it might decide it is a human figure. Your long term memory may then add 'details' to the sighting that you can't really see, like limbs or clothes, because of expectation. Your brain knows, from experience, that humans generally have limbs and clothes, so it inserts such 'details', even though your eyes can't see them. Because seeing a strange figure in a dark place can be a disturbing experience, psychological suggestion may come into play making you think it might be a ghost. If the figure doesn't move, as it might not if it is a shadow with a mundane cause, this strange 'behaviour' may reinforce the idea that it is not an ordinary human at all but a ghost. And even people who don't consciously know much about ghosts will have absorbed enough from the culture to inform such a perception. This process of 'editing' the 'picture in your head' is entirely unconscious. Therefore the image will feel totally real to you and will be remembered as such. The process is probably easier if, whether consciously or otherwise, you accept the idea that ghosts, as well as real people, are possible. This unconscious 'acceptance' may come through cultural memory. Different people will be subject to differing misperceptions because each has their disparate life experiences and memories. That's because misperceptions originate in people's long term visual memory. So if three people see an ambiguous stimulus, one may see one ghost, another a different ghost and the third just a shadow! Misperceptions can also vary according to the viewing conditions. Just as with an optical illusion, they may look completely different from a slightly different viewing angle or may disappear altogether. Thus misperceptions are sensitive to (a) who the viewer is and (b) the viewing conditions. This can make them difficult to reproduce. There are further visual misperception problems related to peripheral vision ('corner of the eye') and low light but they are dealt with elsewhere.
There is no shadow ghost in the photo, just the chance way the shadow fell vaguely suggesting the human form. We humans are particularly prone to seeing figures and faces in random patterns, probably from ancient survival skills. Had the shadow fallen in a different way, the effect probably wouldn't have worked. Indeed, for some readers it probably doesn't work now! The photo was just a normal one of the interior of a building. Nothing has been electronically added to the photo. Instead the whole picture has been simply been darkened and the contrast increased, until the shadow obscures the background, in a photo software package. The final effect is an ambiguous stimulus - is it just a shadow (as the colour and lack of detail suggest) or a shadowy figure (as the shape suggests)? Your brain has conflicting visual cues to resolve - shadow or figure? If you were to approach such a shadow, it would probably change shape or even vanish (as the angles of the light throwing the shadow changed). Since your brain knows that humans can't do things like change shape or vanish, it might conclude the shadow was a ghost! Optical illusions (like these) are a common form of misperception. They usually work by providing conflicting, or ambiguous, visual information. The brain has to make a choice which, with optical illusions, is usually wrong. Again, the brain likes to present a 'reasonable' version of the world (based on experience), rather than a totally realistic one, so it is fooled into making mistakes. Sound misperception This same kind of process that occur in vision perception happen with sound. If you listen to speech in a noisy environment, your brain will 'fill in' likely sounding words that it didn't actually hear. And with ambiguous sounds, you can hear different things, often determined by expectation and suggestion. Flowing water (a kind of near white noise) can sound like whispering or music in certain circumstances. Once again your brain is faced with conflicting or ambiguous cues and has to make a choice. These kind of misperceptions occur in formant noise. You can hear illustrations of these sort of aural misperceptions here. We have a mental map of our body based on vision and touch. However, vision is more important than touch and conflicts between the senses can lead to misperceptions like the 'rubber hand illusion'. You take a model of a hand and put it on a table in front of you while hiding one of your real hands where you can't see it (behind a screen, perhaps) and holding it in the same pose. Then you get someone to gently stroke both the model and your real hidden hand with the same movements. You will get a strange feeling that the rubber hand in front of you is your own! You can see a demo here. It is possible that the Christos method of inducing out of the body experiences may deliberately induce a conflict between vision and touch to manipulate your 'body map'. Now imagine you are sitting in the dark reaching out and you can feel something. Without vision, are you sure you know where your hand is in space? It certainly brings into question spatial awareness and apparent touching incidents in dark vigils. Could it also explain the mystery of the 'hand in the dark' experience at a physical mediumship seance? Attention misperception Another problem that our brain has in constructing the 'picture in your head' is in paying attention. Change blindness is a hot topic in neuroscience at the moment. We seem to only have a limited amount of 'attention' and we only notice so much change, missing any more that happens. For instance, people do not usually notice gradual changes in scenes, even if they are big alterations. We also frequently miss changes if we are distracted while the change is happening. Unfortunately, change blindness can leave us open to not noticing vital clues to natural causes for apparent paranormal phenomena. If an unstable stack of objects was gradually slipping, over several seconds or minutes, we might not notice the change until it finally falls over. We might conclude that the stack had looked perfectly stable until it fell over, because we didn't notice it shifting to an unstable position. We might conclude that the 'object movement' was paranormal when it is not. Paradoxically, we can often have a 'gut feeling' that something has changed in a scene we are observing, even though we can't say what it is. This is mindsight. The interesting point is that, according to research, this can happen both if there is a genuine change in the scene and also if there is not! This could give someone experiencing it the impression that they have perceived something when they have not - a brief sight of a ghost perhaps! This may explain ghost sightings where only one person in a group 'sees' the ghost while others don't, even when they are looking in the same direction. Xenonormal Misperception is probably behind many xenonormal experiences. When faced with something unfamiliar or novel, our brains have to decide what it is before passing it to the 'picture in our head'. An unfamiliar object is an ambiguous stimulus by definition since we have no memory of it. This is when our brains may plunder our long term memory to find ANY match, whether fact or fiction. A mysterious light in the sky may match something seen in a film about UFOs. Though the light is actually just Venus, our brains may add 'details', like a saucer shape, to make it appear more like an alien space craft. By putting images of imaginary alien craft into the public domain, we are encouraging people, very occasionally to actually 'see' them when faced with the unfamiliar, the xenonormal. Misperceptions like those outlined above, coupled with memory limitations, may account for some of the problems we see with witness testimony. © Maurice Townsend 2008 |
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In order to show that something is paranormal, you must first demonstrate that it cannot be explained by natural causes. Though no one seems to compile statistics on 'natural causes', misperception is probably the commonest. It is therefore important that paranormal researchers understand misperceptions in order to eliminate them.