Hallucinations полностью

The ability to imagine smells, in normal circumstances, is not that common — most people cannot imagine smells with any vividness, even though they may be very good at imagining sights or sounds. It is an uncommon gift, as Gordon C. wrote to me in 2011:

Smelling objects that are not visible seems to have been a part of my life for as long as I can remember.… If, for instance, I think for a few minutes about my long dead grandmother, I can almost immediately recall with near perfect sensory awareness the powder that she always used. If I’m writing to someone about lilacs, or any specific flowering plant, my olfactory senses produce that fragrance. This is not to say that merely writing the word “roses” produces the scent; I have to recall a specific instance connected with a rose, or whatever, in order to produce the effect. I always considered this ability to be quite natural, and it wasn’t until adolescence that I discovered that it was not normal for everyone. Now I consider it a wonderful gift of my specific brain.

Most of us, in contrast, have difficulty summoning smells to mind, even with strong suggestion. And it may be oddly difficult to know whether a smell is real or not. Once I revisited the house where I grew up and where my family lived for sixty years. The house had been sold to the British Association of Psychotherapists in 1990, and what used to be our dining room had been turned into an office. When I entered this room on a visit in 1995, I immediately and strongly smelled the kosher red wine which used to be kept in a wooden sideboard next to the dining table and drunk with Kiddush on the Sabbath. Was I just imagining the smell, assisted by these once intensely familiar, beloved surroundings and nearly sixty years of memory and association? Or could a few nanograms of wine have survived all of the repainting and renovation? Smells can be oddly persistent, and I am not sure whether my experience should be called a heightened perception, a hallucination, a memory, or some combination of all these.

My father had an acute sense of smell as a young man, and like all doctors of his generation, he depended on it when seeing patients. He could detect the smell of diabetic urine or of a putrid lung abscess as soon as he entered a patient’s house. A series of sinus infections in middle age blunted his sense of smell, and he could no longer rely on his nose as a diagnostic tool. But he was fortunate that he did not lose his sense of smell entirely, for total loss of the sense of smell — anosmia, which affects perhaps as many as 5 percent of people — causes many problems. People with anosmia cannot smell gas, smoke, or rancid food; they may be beset by social anxiety, not knowing whether they themselves smell of something rank. They cannot enjoy the good smells of the world, either, and they cannot enjoy many of the subtler flavors of food (for most of these depend equally on smell).¹

I wrote about one anosmic patient in The Man Who Mistook His Wife for a Hat. He had suddenly lost all sense of smell, as the result of a head injury. (The long olfactory tracts are easily sheared as they cross the base of the skull, so loss of smell can be caused by a relatively mild head injury.) This man had never given much conscious thought to the sense of smell, but once he lost it, he found his life radically poorer. He missed the smell of people, of books, of the city, of springtime. He hoped against hope that the lost sense would return. And, indeed, it seemed to come back some months later when, to his surprise and delight, he smelled his morning coffee as it was brewing. Tentatively, he tried his pipe, abandoned for many months, and caught a whiff of his favorite aromatic tobacco. He returned, excitedly, to his neurologist, but after careful testing, he was told that there was not a trace of recovery. Clearly, though, he was having an olfactory experience of some sort, and I could only think that his power to imagine smells, at least in situations charged with memories and associations, had been enhanced by his anosmia, perhaps as the power to visualize may be enhanced in some who have lost their sight.

The heightened sensitivity of sensory systems when they have lost their normal input of sight, smell, or sound is not an unmixed blessing, for it may lead to hallucinations of sight, smell, or sound — phantopsia, phantosmia, or phantacusis, to use the old but useful terms. And just as 10 to 20 percent of those who lose their sight get Charles Bonnet syndrome, a similar percentage of those who lose their sense of smell experience the olfactory equivalent. In some cases these phantom smells follow sinus infections or head injuries, but occasionally they are associated with migraine, epilepsy, parkinsonism, PTSD, or other conditions.²