FROM age 13, Daniel Smith’s father heard voices — inner instructions to move a glass across the table or to use this subway turnstile rather than that one. The strain of fighting the voices in secret, Smith believes, led to the psychotic depression his father suffered in his late 30s. The father responded with rage when he later learned that his own father had also heard voices, ones that advised on discards at gin or (less correctly) on bets at the track. What pain could have been avoided if only it had been clear that such voices are not necessarily signals of mental illness.
Smith hopes to make that truth widely known. When people read about “inner voices,” they may think of those commanding a disturbed patient to commit a violent act. But auditory hallucination is common. In one survey, 39 percent of healthy volunteers said they had heard their own thoughts aloud. Another survey found that 13 percent of widows and widowers heard their lost spouse’s voice. In surveys of healthy people, 3 percent or more report a history of vivid auditory hallucination; most do not think the experience calls for treatment.
With the advent of scanners that can track brain activity, neuroscience has taken a new interest in hallucinations. A recent study shows that schizophrenic patients who hear voices activate a language-related region in the right brain when reading, while people who do not hear voices use the left. The researchers suggest that because the “wrong” side of the brain helps process words, hallucinators may generate inner speech that is not attributed to the self. This conclusion is speculative, but the study shows the sort of findings researchers expect — glitches in the biology of producing and interpreting language. Other investigators have had some success treating these hallucinations by applying magnetic fields to specific parts of the brain.
Smith begins his exploration of the neurobiology of hearing with a clever description of what happens, from the vocal chords of the speaker to the neural networks of the hearer, when a wife tells her husband, “I want a divorce.” Smith concludes that hallucinated speech might implicate a range of brain areas controlling such functions as perception, emotion and attention. To try to understand what it’s like to experience auditory hallucination, he dons a headset that plays tapes simulating inner voices and later tests out a “sensory deprivation” flotation chamber. (Neither method succeeds.) He also attends an annual meeting of the Hearing Voices Network, a British organization within a broader movement advocating “liberation, not cure” for psychotic and well-adjusted hallucinators alike.
But Smith’s strongest interest is in hallucination as inspiration. He provides a fascinating account. Generations of religious figures have understood voices as divine. Muhammad heard the Archangel Gabriel order: “Recite!” St. Augustine and John Bunyan (of “The Pilgrim’s Progress”) turned to Scripture at the urging of voices. But with the advent of modernity, inspiration moved away from the aural. In the 16th century, Teresa of Ãvila received divine “locutions” that arrived without sound and argued that nuns with more vivid visitations might be best understood as suffering from mental illness — a position Smith suggests was a way of heading off the Inquisitors.
After St. Teresa, poets either celebrated the loss of “aurality” as a triumph of Christ over the oracles or mourned a loss of direct inspiration. Smith traces the debate, from Milton to Blake to A. E. Housman. Does the muse still speak? Smith tracks down one “automatic writer,” a poet named Sarah Arvio, but she denies that the “voices” she speaks of are auditory hallucinations.
Ultimately, Smith remains agnostic about whether voices convey special wisdom, though he makes a case for taking a nonjudgmental posture toward those who hear them. The association of voice-hearing with religious inspiration cuts two ways. Smith cites the anthropologist Tanya Luhrmann, who found that sensory hallucinations buttressed the faith of a group of evangelical Christians she interviewed, half of whom heard voices. But a doubter might argue that historically religion has benefited from the impulse to assign value to inexplicable phenomena — experiences now better seen through the lens of science. Smith sets (but does not explore) a provocative challenge: Had antipsychotic medication been available, would Moses have dismissed Yahweh’s demands at the burning bush “as his dopamine system playing tricks on him?”
Issues of faith complicate the question impossibly. Presumably a deity who wants to communicate will use convincing means. If the bush is consumed, if the hallucination is treatable, Moses may be right to ignore the sign. Besides, Smith has argued convincingly that we don’t know how biblical experience corresponds to voice-hearing today.
Perhaps we would do better to substitute a future-oriented thought experiment. Imagine that years hence a person hears a voice that can be traced to a misfiring brain circuit that is easily reregulated by the application of a magnet. Will that message have special standing, above the same idea arrived at in more ordinary fashion? Individuals might answer the question differently, just as Smith’s tortured father and his more accepting grandfather responded to voice-hearing in different ways. But it seems likely that a society with such medical capacities would move further down the trail blazed by St. Teresa, toward neurological and away from mystical understandings of the voices in our heads.
Peter D. Kramer is the author of “Against Depression” and, most recently, “Freud: Inventor of the Modern Mind.”