Patients with Alzheimer's disease and dementia are to be helped to talk to their family and friends using a hi-tech device to trigger memories.

One of the most distressing aspects of the dementia can be the person's loss of short-term memory.

But long-term memories often stay strong, and researchers from the Universities of Dundee and St Andrews in Scotland have devised a touch-screen multimedia system which patients and carers can use as a conversation aid.

A prototype of the Computer Interactive Reminiscence Conversation Aid (CIRCA) will be given a special demonstration at the University of Dundee on Saturday to mark World Alzheimer's Day.

Anything that acts as a memory prompt is an important development

Simon Denegri, Alzheimer's Society

The Circa system will use video, songs and pictures to prompt memories and conversation.

The research team includes software designers, multimedia designers and psychologists,

They are hoping to trigger different kinds of memories: Global - news events or clips of old movie stars such as Clark Gable and Vivian Leigh, and local - scenes from old Dundee including berry picking and jute mills.

Eventually they also hope to be able to tailor the system to include personal memories too.

A moment of connection

Around 40 Alzheimer's patients and their families are helping researchers hone the design of the Circa system.

Dr Norman Alm, a software engineer working on the project, told BBC News Online: "The idea came from a visit I made to a nursing home.

"The managers said how hard it was for family members who had very difficult visits with relatives - often they stopped coming.

"They said 'even just a moment' of connection would be significant."

Dr Alm said the touch screens could cost up to �3,000, but prices were coming down all the time.

He added: "It could be something that is more useful in a group environment.

"We are interested in looking beyond this and trying to develop entertainment systems for people with dementia."

Difficult

Simon Denegri, associate chief executive of the Alzheimer's Society, told BBC News Online said it could help relieve the "emotional stress" of living with Alzheimer's.

"It's certainly true that short-term memory loss is one of the most difficult things that both the person with dementia and their families experience.

"Anything that acts as a memory prompt is an important development."