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WILLIAM SHAKESPEARE described old age as “second childishness”—sans teeth, sans eyes, sans taste. In the case of taste he may, musically speaking, have been even more perceptive than he realised. A paper in Neurology by Giovanni Frisoni and his colleagues at the National Centre for Research and Care of Alzheimer’s Disease in Brescia, Italy, shows that one form of senile dementia can affect musical desires in ways that suggest a regression, if not to infancy, then at least to a patient’s teens.

Frontotemporal dementia is caused, as its name suggests, by damage to the front and sides of the brain. These regions are concerned with speech, and with such “higher” functions as abstract thinking and judgment. Frontotemporal damage therefore produces different symptoms from the loss of memory associated with Alzheimer’s disease, a more familiar dementia that affects the hippocampus and amygdala in the middle of the brain. Frontotemporal dementia is also rarer than Alzheimer’s. In the past five years the centre in Brescia has treated some 1,500 Alzheimer’s patients; it has seen only 46 with frontotemporal dementia.

Two of those patients intrigued Dr Frisoni. One was a 68-year-old lawyer, the other a 73-year-old housewife. Both had undamaged memories, but displayed the sorts of defect associated with frontotemporal dementia—a diagnosis that was confirmed by brain scanning.

About two years after he was first diagnosed the lawyer, once a classical music lover who referred to pop music as “mere noise”, started listening to the Italian pop band “883”. As his command of language and his emotional attachments to friends and family deteriorated, he continued to listen to the band at full volume for many hours a day. The housewife had not even had the lawyer’s love of classical music, having never enjoyed music of any sort in the past. But about a year after her diagnosis she became very interested in the songs that her 11-year-old granddaughter was listening to.

This kind of change in musical taste was not seen in any of the Alzheimer’s patients, and thus appears to be specific to those with frontotemporal dementia. And other studies have remarked on how frontotemporal-dementia patients sometimes gain new talents. Five sufferers who developed artistic abilities are known. And in another lapse of musical taste, one woman with the disease suddenly started composing and singing country and western songs.

Dr Frisoni speculates that the illness is causing people to develop a new attitude towards novel experiences. Previous studies of novelty-seeking behaviour suggest that it is managed by the brain’s right frontal lobe. A predominance of the right over the left frontal lobe, caused by damage to the latter, might thus lead to a quest for new experience. Alternatively, the damage may have affected some specific neural circuit that is needed to appreciate certain kinds of music. Whether that is a gain or a loss is a different matter. As Dr Frisoni puts it in his article, de gustibus non disputandum est. Or, in plainer words, there is no accounting for taste.