Most people that consider themselves scientists quickly reject the notion that so-called “paranormal” experiences are, in fact, real. And by “real”, I mean based in a physiological reality other than abnormal brain function. Claims of extra-sensory perceptions such as mind-reading, clairvoyance, auroras, etc. are widely met with skepticism, patronizing indulgence, or hostility. And no doubt some of these reactions are perfectly appropriate at any given time as there is no shortage of tricksters, delusional braggarts, and out-right charlatans. But before we toss the entire concept of extra-sensory perception on the trash heap and dust our hands of it, let’s take a scientific approach to the question “Can claims of ESP be explained scientifically?” My answer, as you may have already guessed, is: Yes. Here goes:
To begin, consider the smell of cyanide. As about 40% of you know from personal experience, cyanide elicits the aroma of bitter almonds. For those of you that have never smelled this odor, there is a reason – you lack the necessary genetic information to decode the chemosensors that cyanide produces and that allow some individuals to ascertain the scent of bitter almonds. Since the chemical signals that cyanide emits can be detected by other means and measured, we can conclude that the information exists in the environment as a constant. The means of decoding that signal, however, lies within the genetic parameters of the person exposed to the signal. There are very good reasons for humans to be able to detect the scent of cyanide as its ingestion can cause death, an inconvenient fact that was countered evolutionarily by selecting for a genetic makeup that enables a fair amount of the population to detect the poison and to therefore avoid it. Since we are no longer dependent upon foraging for food and taking our chances with the suitability of food sources by trial and error, the lack of a cyanide-sensing gene is no longer strongly selected against, which may explain why the prevalence is only about 40% in the population.
Detecting the smell of cyanide is an interesting case, but as there is a substantial proportion of the population that can detect the odor, there is little argument about its existence (even if there is an even larger portion of the population that is completely unable to detect the same scent). So let’s take a rarer example – synesthesia. Synesthesia is the detection of traditional sensory signals by a different sense. For example, visually associating letters or numbers with colors, hearing musical tones when visually stimulated by specific colors, or seeing colors associated with individuals. Typically, synesthetics do not necessarily replace one sense with another, but instead have a combination of two – hearing and seeing colors or seeing both characters and colors at the same time. There is some interest in the scientific community to better understand this “disorder” which has led to some fascinating findings. For one, children who “see” numbers or letters continue to do so throughout their life (and frequently have another parent or relative who also had unusual perception). The association of specific colors with specific characters does not change. This argues that the perceptual “defect” is inherent, not acquired or temporary. Individuals with synesthesia are also more likely to have relatives with other neurological conditions such as autism arguing that synesthesia may also have a genetic basis.
Like the genetic ability to detect the odor of cyanide, synesthetics have by virtue of their unusual genetic make-up, the ability to derive information from their environment that others cannot. A fascinating example of this was included in a 2003 Scientific American article about synesthesia called “Hearing colors tasting shapes”. An adult male with color/number synesthesia was administered a series of tests that evaluate visual perception. Individual with normal visual perception can distinguish the number 3 in their peripheral field when it is printed alone. But if the 3 is surrounded by 5, visually normal people can no longer distinguish the numeral. The synesthetic test subject, however, consistently saw the color blue in addition to the numeral 3. When the numeral was surrounded by 5s, he could still perceive the color blue – and deduce that the numeral was a 3. His visual perception of the numeral was no different than that of a non-synesthetic, but the association of color allowed him to correctly identify the number.
How might this happen and what does this tell us about perception in general? First, we must conclude from the experiment above that synesthetics so not simply re-route information once it has reached their brain. If that were the case, the man would not have been able to see “blue” unless he could first deduce the number “3”. Rather, it would seem that the de novo information that his brain was decoding contained a signal that could be interpreted as *both* a numeral and as a color thanks to the genetic program that is responsible for his brain function. Let’s accept that premise and run with it for a minute. An environmental signal that can be interpreted, ie “sensed”, in different ways. Apply that concept to cases of individuals that “hear” color and we arrive at the rather startling concept that frequencies of light and sound are not absolute. Rather, they are units of energy in our environment that are turned into “sounds” and “colors” only within the confines of our own brains. 440Hz sounds like the pitch “A” only because the majority of us, by evolutionary selection, perceive it as such. Had human evolution taken a left turn rather than a right 100 million years ago, it is conceivable that we would instead know 440Hz as the color red rather than a pitch. Apparently, a small minority of humans *did* at least partially veer left at that sensory fork in the road and have retained the ability to assign multiple perceptions to the same environmental energies for which most of us can only conceive of one.
If we now go back to the visual perception tests of the synesthetic described in the article, we can appreciate the fact that due to his unique sensory perception, he is able to extract information from his environment that is inaccessible to individuals with normal visual perception. The information remains a constant in the environment – much like the molecules that some individuals perceive as an odor similar to almonds that is emitted by cyanide – but is only understood within the limits of the person processing the signal. To wit, synesthetics have “extra-sensory” perception – at least compared to the rest of us.
So, you ask, can this theory be applied to anything other than parlor tricks and very high scores on visual tests? Absolutely. One example is that individuals that associate color with people are probably the basis for the paranormal determination of auras. In the context of the argument I have proposed thus far, it is not difficult to formulate a mechanism for such ability. Individuals are known to emit chemical signals in the form of pheromones. Pheromones are far better understood in the context of what they can *do* – influence attraction, convey emotionals, transmit hormonal status during reproductive cycles – rather than what they are. Our perception of them is part olfactory, part mechano-sensory, perhaps, but the act that we derive information from pheromones in our environment is clear. The perception of auras, therefore, may be as simple as an individual decoding pheromones in a visual and color sense rather than (or in addition to) an odiferous or mechano-sensory way. Simply put, auras may be the result of seeing pheromones rather than smelling them.
Evolutionarily, there is probably little or no survival advantage for seeing auras, hearing colors, or identifying written characters by their hue. On the contrary, such abilities have likely been actively selected against, as claims of paranormal abilities are usually assumed to stem from mental defect.
Does the smell of cyanide and blue 2s explain all paranormal claims? Probably not. Human nature being what it is, the desire to pull one over on the next guy is sufficient to ensure that most claims of extra-sensory perception are merely fanciful – or entertaining (here’s to you, Mr. Blaine). However, the idea that energy within our environment – energy that is constant whether the signal is detected or decoded – can be interpreted in more than one way, may be a rational basis for a host of other claims that seem to the rest of us to defy believability. Can the electrical impulses of one person’s neuronal activity be sensed as sound, color, thoughts by another person? Do pheromones persist in some environments over time, to be later interpreted as colors or sounds by a passerby? I suggest that such possibilities do exist. As such, a range of paranormal experiences may, in fact, be physiologically based and completely rational. As for those of us with normal senses, I understand that LSD can produce a phenomenon similar to that described by synesthetics. Not that I’m suggesting anything……