Scientists think there's a tenuous but plausible hypothetical link between picking your nose and an increased risk of developing dementia. In cases where picking at your nose causes internal tissue damage, critical species of bacteria have a clearer path to the brain, which responds to their presence in ways that resemble signs of Alzheimer's disease. There are numerous caveats here, not the least of which is that the supporting research so far is in mice rather than humans. But the findings