Using Neuroscience to Debunk the Paranormal
Extrasensory perception, or ESP, is one of the most widely accepted paranormal phenomena, with almost half of adults in the United States affirming its existence. Under the rubric of ESP fall mental processes that are considered outside the normal range of thought, such as predicting the future, reading other people’s minds (telepathy), and knowing of distant events as they occur (clairvoyance). Detractors claim no reliable evidence of ESP has ever been presented, while supporters assert they have experienced these extraordinary thoughts, such as knowing someone was going to call right before the phone rang.
These areas are difficult for scientists because, although no scientific evidence exists to support such claims, they are also very difficult to disprove. It is clearly possible someone believes they had an eerie feeling at just the same moment a friend was involved in a car crash. A scientist might argue, however, that the person remembers a chill he had which would normally have been ignored, but now is remembered in conjunction with a disturbing event. The association is made after the fact, but remembered as if it were made beforehand. The same applies to the case of thinking about a friend, then hearing the phone ring and being surprised to hear her voice on the other end of the line. You may have thought about her a hundred times in the week before this call, but it is only considered a memorable event when the phone coincidentally rings during one of those times. Those who believe in ESP might ascribe this to telepathy, but a scientist might suggest this is due to coincidence and the human tendency to remember things through association. Still, it is hard to prove it’s not because of ESP.
A group of psychologists at Harvard University are using neuroimaging to try get to the bottom of this issue. Samuel Moulton and Stephen Kosslyn used fMRI to study participants as they viewed ESP and non-ESP stimuli. The non-ESP stimuli were pictures simply presented visually. The ESP stimuli were presented visually as well in three other ways. First, to measure telepathy, they were shown to the participants’ identical twin, relative, romantic partner, or friend, who was seated in another room. Then, to measure clairvoyance, they were displayed on a computer screen located out of sight of the participant. To measure precognition, the pictures were shown later (in the future).
They found no difference in the way the brain reacted to the ESP and the non-ESP stimuli, although there was a difference in the emotional importance the participants’ ascribed to the ESP stimuli. This finding supports the concept mentioned above, where we may assign significance to an event, then later correlate that event with a paranormal explanation. The researchers are the first to point out that this doesn’t prove ESP is not real. Once again, it’s hard to prove something like ESP doesn’t exist, as proponents can simply claim it is not measurable in this way (neuroimaging). But Moulton feels this is the best evidence against ESP thus far.
