Not our houses but our brains are haunted. (G.M. Beard, 1879)
Neuroscience will one day provide explanations for what most people call ‘paranormal’ phenomena. These are more accurately described as anomalous psychological experiences, and are broadly defined as those experiences which cannot be accounted for using conventional scientific explanations.
We can (and should) deny the existence of ghosts and UFOs. Phenomenologically, however, the paranormal experiences of individuals are very real. Paranormal phenomena are altered states of consciousness brought about by changes in the electrochemical activity of the brain.
As will become clear below, some of the subjective experiences of these individuals can be explained in neuroscientific terms. It will eventually be shown that all paranormal experiences are neurogenic in nature – that is, they originate in the brain and its activity. Some of these phenomena, such as hauntings, can be explained by patterns of brain activity; others, such as ‘automatic writing’, can be explained by certain neuropsychiatric conditions. Paranormal belief systems are associated with particular personality characteristics, and some paranormal phenomena have their basis in psychopathology.
Belief in paranormal phenomena is an example of ‘magical thinking,’ or non-scientific causal reasoning. Magical thinking has several elements, such as believing in the interconnectedness of all things through forces that transcend the physical world, investing symbolic objects with special powers, and making causal connections between seemingly unrelated events.
Psychologists have studied paranormal (or ‘psi’) phenomena in some depth but the field of parapsychology remains controversial within the mainstream scientific community. Most scientists regard parasychology as a pseudoscience, because it leads us towards superstition and magical thinking, whereas the ‘real’ sciences move away from them. The standing of parapsychology among scientists is not helped by the mysticism surrounding these phenomena, or the large number of fraudsters, incompetent researchers and hoaxes associated with the field.
Despite this, paranormal beliefs are hugely popular and widespread. This is reflected in the success of television programmes like The X Files. According to a Gallop poll conducted last year, 75% of Americans have some kind of paranormal belief, and a Daily Mail poll (2nd Feb. 1998) put the figure of British people with such beliefs at over 60%.
There is a huge diversity of psi phenomena; below is a list of some of the more common ones.
- belief in UFOs
- extra-sensory perception (ESP)
- facilitated communication (e.g. ‘automatic writing’)
- out-of-body experiences
- precognition/ premonitions
- poltergeist hauntings
This list is by no means exhaustive, and I will only try to explain a few of them in terms of neurobiology.
Individuals who report experiencing psi phenomena are known to have certain personality characteristics. It is found, for example, that people with paranormal beliefs more readily make associations between unrelated words or events than do people without paranormal beliefs. They are also more creative and prone to fantasy than others.
People who have paranormal experiences may also be prone to visual and auditory hallucinations. Schizophrenics, and, to a far lesser extent, ‘normal’ people, experience auditory hallucinations. These ‘voices’ are known to be generated by the brain, but those who experience them deny that they originate from there, even though neuroimaging studies have shown that the voices are generated by activity in the neuronal circuits normally associated with speech production.
All psi phenomena include a blurring of the distinction between perception and imagination; many involve reports of a sensed presence and distortions in the perception of time. Claims of experiencing the presence of ghosts or spirits are particularly common. Many alleged sightings of ghosts take place in specific places and are usually associated with loud noises, strange smells and apparitions.
It is well documented that patients with temporal lobe epilepsy often report having paranormal or religious experiences. In fact, both kinds of experiences can be evoked experimentally by magnetic stimultaion of the temporoparietal region. These regions, which are involved in awareness of the ‘self’, trigger the experience of a sensed presence when stimulated.
Michael Persinger, a professor of neuroscience at Laurentian University in Ontario, Canada, was the first to suggest that electromagnetism can affect brain activity, and has evoked spiritual and paranormal experiences in people in this way. Persinger believes that brain activity can explain anything that might be described as a paranormal experience, including apparitions, aliens, near-death experiences and past-life sensations.
It seems very plausible, then, that claims of ghost sightings can be explained in terms of magnetism. A ‘haunted house’ may be located in an area with a particularly strong geomagnetic field, or one which is prone to large fluctuations in its geomagnetic field. This would alter the temporal lobe activity of people entering the area, evoking in them the experience of a sensed presence, or a ‘ghost’.
Automatic writing (or ‘trance’ writing) is a form of facilitated communication involving the production of written material which is alleged to come from somewhere other than the conscious thought of the writer, and is another phenomenon frequently used as evidence of the existence of ghosts or spirits. It is frequently claimed that the written material is being produced by a spirit from another world who has temporarily possessed an individual’s hand or arm in order to communicate.
A precursor to facilitated communication is the famous case of Clever Hans, a horse trained by the retired schoolteacher Wilhelm von Osten. Around the beginning of the twentieth century, von Osten claimed that his horse could count, read and respond to simple yes or no answer questions, becoming an international celebrity as a result. For example, when asked by von Osten to calculate 7 times 3, Clever Hans would gently pat his paw on the ground 21 times.
The claims by von Osten that Clever Hans could actually count and read were soon discredited. It soon became evident that, rather than having a real understanding or an ability to communicate, the horse was responding to subtle visual cues provided by von Osten with simple motor behaviours. von Osten, however, always denied that he had conditioned Clever Hans to perform movements in response to specific cues; i.e. von Osten was denying ownership of the movements he performed and to which Clever Hans responded.
Certain neuropsychiatric conditions are known to produce symptoms of the denial of ownership of one’s motor behaviours. This involves a breakdown in the link between one’s behaviour or experiences and the awareness that one is an agent who is responsible for those behaviours.
Somatoparaphrenia, or delusional beliefs about one’s own body, such as the ownership of a limb by another person, is a condition that can be caused by right hemisphere stroke or other types of damage to the brain. It is also relatively common in schizophrenic patients. Somatoparaphrenic patients typically think that a paralyzed limb belongs to their docotr or spouse; this is sometimes accompanied by complex hallucinations.
‘Alien hand syndrome’ is a similar condition in which the ownership of motor behaviours is denied. Patients exhibiting alien hand sydrome have a partial disconnection of the anterior corpus callosum, the bundle of one hundred million fibres connecting the two hemispheres of the brain. One phenomenon that might be explained by alien hand syndrome is the ouji board. Psychics claim that during seances they can use ouji boards to communicate with the spirits of deceased people. It is likely that the board is actually being controlled by the psychic, who will, of course, deny this vehemently.
Alien hand syndrome is also demonstrated by split brain patients. These are epileptics who have had commissurotomies (severing of the corpus callosum) to prevent the spread of epilepsy from one hemisphere of the brain to the another. The commisurotomy is a drastic procedure that was used in patients with severe, untreatable epilepsy.
Amazingly, split brain patients behave completely normally most of the time. Only under experimental conditions do the bizarre effects of their surgery become evident. Roger Sperry and Michael Gazzaniga conducted classic experiments on split brain patients in the 1960s.
In one set of experiments, patients sat at a table with a screen attached to it. Under the screen were various objects which the patients could feel but not see. Patients were asked to pick up objects and describe them. When patients picked up an object with their right hand, the tactile information about that object is transmitted to the left hemisphere, which contains the speech centres, and the patient is able to name the object. If, however, the patient picks up an object with the left hand, the same information is processed by the right hemisphere. Because the connections between the two hemispheres have been severed, the information about the object cannot be transmitted to the speech centres in the left hemisphere, and the patient cannot name the object.
Occassionally, split brain patients behave bizarrely in normal situations. When dressing, for example, they have been known to choose a garment of clothing with one hand, only to snatch it and throw it back into the wardrobe with the other!
Why do split brain patients behave in this way? First, there is contralateral control of the body by the brain. The left hemisphere controls and recieves information from the right side of the body, and vice versa. That there is a localization of brain function, with the left hemisphere specialized for certain functions and the right for others, has been known for a long time.
The study of split brain patients clearly shows that the two hemispheres of the brain control different aspects of thought and action. The process of disconnecting the two hemispheres of the brain bifurcates the the mind. The split brain patient sometimes behaves as if they have two minds, or as if there are two different people inhabiting the same body. The two hemispheres of the brain produce different aspects of consciousness which are normally unified. This unity is sometimes lost in the split brain patient. In the words of Sperry, each hemisphere constitutes “two separate realms of conscious awareness; two sensing, perceiving, thinking and remembering systems.”
Undoubtedly, as our understanding of brain function increases, the neurosciences will provide explanations for more of these phenomena, and advances in consciousness studies, combined with quantum physics, may one day explain others. A paranormal experience, like a religious one, is an altered state of consciousness. To gain an understanding of these altered state of consciousness is to better understand the nature of consciousness itself.