What's that, out of the corner of your eye, lurking in the periphery? It's a colorful shape of some kind, slowly creeping into the foreground. But wait, now it has taken the form of a bright, pink pig, oinking with gusto. The shimmering swine hovers in midair for a few moments, until it suddenly plops out of existence.
Under normal circumstances, If you experienced a hallucination like this, rational thinking might lead you to one logical conclusion: You're going totally bonkers. But are you really?
Almost certainly not, says New York University neurologist Oliver Sacks. Hallucinations aren't solely limited to the realms of psychoactive drugs and mental illness. In fact, they're actually quite prevalent among the general population. In 2000, Stanford researchers surveyed 13,000 people on the matter. 38.7% of respondents reported experiencing some form of hallucination at one point in their lives.
A 1993 study examined a more sensitive topic: seeing the dead. Researchers queried 14 men and 36 women in their early seventies who had lost a loved one in the previous year. About one-third of the subjects reported seeing, hearing, or talking to their deceased spouses in the months following their death. Contrary to what you might think, those that experienced these hallucinations considered them "helpful" to the grieving process.
Though recent evidence shows that sane people commonly hallucinate, the link between hallucinations and mental illness has been around much longer. Thus, "seeing things" is often thought to be synonymous with insanity. In a recent piece for the New York Times, Sacks wrote:
In a famous 1973 study by the Stanford psychologist David Rosenhan,
eight "pseudopatients" presented themselves at various hospitals across
the country, saying that they "heard voices." All behaved normally
otherwise, but were nonetheless determined to be (and treated as)
schizophrenic (apart from one, who was given the diagnosis of
WHILE many people with schizophrenia do hear voices at certain times inAnd why shouldn't hallucinations be normal? After all, the eyes and ears really only serve as gateways to the outside world. Ultimately, we see and hear with our brains.
their lives, the inverse is not true: most people who hear voices (as
much as 10 percent of the population) are not mentally ill. For them,
hearing voices is a normal mode of experience.
hallucinate faces, or in the insular cortex when people hallucinate smells.
"Sometimes there may actually be something wrong there, and there's a
hemorrhage or a seizure focus, but sometimes, as with the sense-deprived
people, it's just as if normal constraints have been removed and a
whole area has sort of become anarchically active and is just doing its
thing," Sacks told Science Friday.
Someday you might find yourself lying comfortably in bed, eyelids closed, when suddenly, geometric shapes, faces, or even landscapes pop into view, perhaps accompanied by doorbell rings, crashes or bangs -- a hypnagogic hallucination. Or you might awaken bright and early, and with open eyes, see a large swooping owl with claws outstretched, or an enormous spider clinging to its web in the corner -- a hypnopompic hallucination.
If these hallucinations excessively recur or grow overly disturbing, you might want to visit a neurologist or a psychiatrist. But all in all, don't fret.
You're not going insane.
(Photo: Abstract Image via Shutterstock)