Free What the Nose Knows: The Science of Scent in Everyday Life by Avery Gilbert

realization that millions of Americans suffer from smell loss spurred the National Institutes of Health to underwrite basic research into odor perception. The ultimate goal of this work was to find ways to cure smell loss. Yet, despite decades of substantial funding, effective medical treatment remains elusive.
    Sudden smell loss is psychologically devastating. By far the biggest impact is on eating: anosmia steals the pleasures of the table. Without its aroma, food in the mouth becomes a bland, chewy mass, and drinks become equally flavorless. Faced with dull food, some people lose appetite, eat less, and lose weight; others eat to feel full and end up gaining weight. Smell loss can alter mood—patients often show symptoms of depression, and psychological well-being, friendship, emotional stability, and leisure activities all take a hit. Some people find that their sex life suffers. In the wake of smell loss comes the anxiety of constant vigilance. Anosmics worry about gas leaks, undetected fire, spoiled food, and lapses in personal hygiene. They adopt coping strategies such as frequent bathing and laundering. Anosmics report smell-related hazardous events—burning a pot or eating spoiled food—more often than normal smellers, but there is little data to suggest a higher rate of actual injury.
    In rare instances, people are born without a sense of smell. As it’s hard to miss what you’ve never known, people who are anosmic from birth tend to regard their condition with bemusement. A few even manage to find a silver lining. The ex-boyfriend of a young English anosmic told her, “You were the best girlfriend in the world. You let me bring curry home from the pub every night, and I could fart as much as I liked.” One newspaper reporter who is smell-blind from birth regularly covers smelly stories for a major U.S. daily. This is either a heartwarming story of a disability overcome, or journalistic malpractice of the first order. Perhaps, in a zany way, it is both.
    Somewhere off the main continuum of normal to partial to complete smell loss lie the bizarre pathologies of odor perception. A person with phantosmia, for example, perceives a smell when none is there. These olfactory hallucinations can be vague (“a chemical smell”) or quite specific (one patient said, “It reminds me of a flower I smelled in Samoa”). Phantosmia is a tricky diagnosis for a doctor to make: the hallucinated smell comes and goes and may not occur in the course of an office visit. The physician must first rule out all possible organic sources for the weird smell, especially sinus or gum disease. The physical causes of phantosmia are diverse and include seizure, migraine, and brain tumor. When a real odor gives rise to a distorted perception, the condition is called parosmia. The distortions in such cases are almost always unpleasant; patients say things smell foul, rotten, or burned. Such was the case of a sixty-year old woman who awoke one morning to find that every odor smelled like burnt toast. Eleven years later, despite treatment with antibiotics, antivirals, vitamins, beta-blockers, anticonvulsants, and zinc sulfate, her condition was unchanged. Most parosmics can tell you which smells are distorted; the most common are gasoline, tobacco, coffee, perfumes, fruits (mainly citrus and melon), and chocolate. Parosmia almost always occurs after an upper-respiratory-tract infection or head trauma, where smell function is reduced but not completely gone. This leads researchers to speculate that parosmia is an “incorrect rewiring” of the connections among regenerating nerve cells following damage to the olfactory system. Among smell pathologies, the most appalling is cacosmia, in which everything smells like shit.
    In Philip K. Dick’s sci-fi novel
The Simulacra
(1964), there is a character named Richard Kongrosian, a psionic pianist who plays the instrument telekinetically. He also has a history of mental instability. An annoying