According to an article I came across today, people with good language skills early in life and develop dementia later in life are likely retain their memories better than those without such skills. They believe that testing the mental abilities of people in their early 20s can predict whether they will retain their mental abilities in their 70s and 80s.
It doesn’t say whether this involves language skills in one language or more than one, but other studies have found that being bilingual or multilingual can delay by several years the onset of Alzheimer’s and other conditions that tend to strike the elderly.
The article caught my eye because last night I sang with the Bangor Community Choir at Plas Maesincla, a care home for people with dementia in Caernarfon. Many of the residents perked up when we sang some well-known Welsh songs, such as Calon Lân and Sospan Fach, and quite a few joined in. So I think the songs might have triggered some happy memories.