When elderly people develop dementia their short-term memory fails them: new information is no longer being stored. Things as basic as the place they are in and who is present may fade. This scenario appears insurmountably tragic until you hear about the bucketloads of evidence proving that the long-term memories of people with dementia are often wholly intact. Studies using brain scanners prove that, when consulting old memories, the brain works quite normally in those with dementia.

One area where this is already understood to a certain degree is art therapy. Patients with dementia are often exposed to art. Some studies show that, not surprisingly, whether a trained artist or not, abilities in creating art decline with dementia.

However, until now there has been no study of how the illness affects art appreciation. A new one neatly illustrates the endurance of long-term memory in dementia as well as the potential for continued appreciation of art to contribute to wellbeing. A sample of people with dementia and a control group of unaffected older people were shown 24 postcards with three different kinds of painting on them: representational (of views or people), semi-representational and abstract.

Both samples were asked to order the postcards according to which they liked best, thereby displaying aesthetic preferences. The pictures were not likely to be previously known.

Two weeks later, the same procedure was followed. The object was to find out if the people with dementia would be liable to order the postcards in roughly the same fashion as the first occasion and, indeed, this was the case. It was also found that they were no more likely than the control group to change their order of preference - their aesthetic preferences, stored in their long-term memory, remained constant.

Since one's aesthetics are a significant component of who one is at a deep level, this study is hard evidence that the integrity of this aspect of the personality of people with dementia is every bit as great as the unimpaired. And on a practical plane, here is good reason to persevere in trying to relate to people with dementia through their favoured artistic loves.

It is yet more evidence in support of the Specal (Specialised Early Care for Alzheimers) method developed by my mother-in-law, Penny Garner. She advocates establishing which themes from the old memories are happy ones, and developing a whole care programme organised around them (see my book about her work, Contented Dementia). For me the soundtrack would be a mix of Lou Reed's Berlin and David Bowie's Ziggy Stardust, but everyone will have a different list. One key to wellbeing in dementia is to constantly play the soundtrack of your desert island discs to a backdrop of your favourite art.

- Aesthetics study: Halpern, A et al, 2008, Brain and Cognition, 66(1), 65-72. More Oliver James at selfishcapitalist.com