Understanding a little about the biology of dementia can demystify it, and Teepa Snow is an occupational therapist and educator who has made it her mission to do just that. Dementia is not a single disease, but more of an umbrella term for cognitive changes that can affect a person as they age. We commonly think of it as memory loss, but dementia can take many other shapes as well, affecting the mind and the body in ways that can seem bizarre and inexplicable to a caregiver.