Byline: Hannah Shaddock
MARGARET TORRANCE often plays the piano for a rapt audience, reeling off one note-perfect tune after another without so much as a glance at a sheet of music.
She also has trouble remembering her daughter's name, does not know she has grandchildren and struggles to hold a conversation lasting longer than a few minutes.
Margaret is 81, and was diagnosed with vascular dementia four years ago. She has been in a care home since July 2010.
A talented pianist, she regularly plays for other residents on the piano which she and her husband bought in the 1950s and which her daughter, Jan, gave to the home so her mother could continue doing what she loved.
Margaret's talent is remarkable, but the fact that she remains able to play music despite suffering from advanced dementia is not.
It is well documented that the capacity to remember music - whether it's the ability to play an instrument or recite the lyrics to our favourite song - remains one of the last to leave us.
Dr Vicky Williamson, a research fellow at Goldsmith's University in London who specialises in the relationship between music and memory, explains that, in physiological terms, it is unsurprising that the two are so closely linked.
"There are very direct, close connections between the music that we like - which activate these emotion and reward sensors - and your hippocampus, which is where all your emotions are stored," she says.
She explains that even those in advanced stages of dementia are still likely to remember music learnt as a child or teenager, as memory loss tends to work backwards, eroding the most recent memories first.
As a result of the strong relationship between music and memory, singing, playing an instrument or just hearing a familiar tune can all have a therapeutic effect on dementia sufferers.
For Margaret, music is a way of managing her condition, calming her when she becomes distressed or disoriented.
"There were times when Mum was very anxious to get out of the home," says her daughter Jan.
"She thinks a lot about her mum and dad and talks about them all the time, and has spells where she's very unsettled and wants to get out. The piano is a way of diverting her. It really helps."
With a growing elderly population, dementia is a particular concern in the UK, where a person is diagnosed with dementia every 3.2 minutes. It affects well over a million people: 800,000 sufferers and their 670,000 carers.
The condition also costs the UK billions every year - twice as much as cancer - but spending on dementia is only a fraction of the millions ploughed into cancer research, according to figures released in 2010.
There are two main kinds of dementia: vascular dementia, which is caused by problems with the blood supply to the brain, and Alzheimer's disease, which is the most common form.
However, "dementia" technically describes a set of symptoms - including memory loss, difficulty communicating and reasoning, and dramatic mood swings - and so can also be part of other neurological conditions such as Huntington's disease and Parkinson's disease.
Last year Prime Minister David Cameron launched a campaign to improve public understanding of dementia, as early symptoms are often dismissed as a "normal" part of ageing.
There's currently no cure and, when dementia is diagnosed, nobody can tell you precisely how things will progress. While one person may be lucid for several years before beginning to deteriorate, another may be in a care home within months.
Music is a key It can be extremely difficult to live with, and one of the cruellest aspects of the disease is memory loss. …