A researcher explains why the link between loneliness and memory loss may be more nuanced than scientists thought. (Image credit: Westend61 via Getty Images) Loneliness is something most of us will experience at some point. It is a normal emotion, not a character flaw. But it is also something that can quietly affect how we think and remember, and researchers have long debated whether it might even raise the risk of dementia . A new study , published in [the journal] Aging and Mental Health, suggests the picture is more complicated than either side of that debate has allowed for. First, it is worth being clear about what dementia actually is. It is not a single diagnosis but an umbrella term covering a range of conditions — the most familiar being Alzheimer's disease — that cause memory loss, confusion, difficulties with language and a gradual loss of independence. Cognitive decline, meaning a general slowing or weakening of mental function, is not the same thing.…