Hearing voices

A hearing test may help predict schizophrenia.

Gregory Nemec

Gregory Nemec

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When mentally troubled people hear meaning in noise that sounds meaningless to others, they may be exhibiting an early warning sign of schizophrenia, according to researchers at the School of Medicine.

Ralph Hoffman, a professor of psychiatry, and his colleagues studied 43 individuals who showed preliminary indications of psychosis. During the research, some received an anti-psychotic medication, others a placebo. Building on studies linking schizophrenia and speech processing, the researchers asked each participant to listen to two-and-a-half minutes of prerecorded babble: six speakers reading overlapping texts. As they listened, the participants were to repeat any words or phrases they could make out. (The study appeared in October in the British Journal of Psychiatry.)

In the mingled voices, the participants consistently identified only four individual words correctly. (They were "children," "A-OK," "Republican," and "increase.") But a number of the subjects also thought they heard phrases of two or more words. "We don't think that what they were 'hearing' had to do with anything that was actually being said," says Hoffman. "Rather, the babble produced an abnormal brain activation, and each person's perceptions were different."

Hoffman's team followed participants for up to two years and found that 80 percent who had "heard" phrases consisting of at least four words developed symptoms of schizophrenia during times when they were not taking anti-psychotic drugs. In contrast, only 6 percent of participants who "heard" phrases consisting of three words or fewer developed symptoms when not taking the drugs.

If the findings are confirmed by further research, this kind of "speech illusion" assessment could provide a simple, inexpensive way to identify people who might benefit from drug therapy to prevent schizophrenia. And although the study sample was small, Hoffman adds, the results also suggest something profound about the brains of those at risk for the disease: they "may be programmed to seek meaning when no meaning is there."

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