Johnson’s reliance on the tote bag is a radical extension of what humans naturally do. In 1998, the philosophers Andy Clark and David Chalmers introduced the idea of “the extended mind,” arguing that it makes no sense to define cognition as an activity bounded by the human skull. Humans are masters of mental outsourcing: we archive ideas on paper, we let Google Maps guide us home, and we enlist a spouse to remember where our wallet is. Johnson’s main cognitive prosthetic is Aline: she trusts her sister’s account of her life as strongly as she used to trust her own memory. This is unusual but not unreasonable, and, given the way that emotions can distort old memories, Aline’s accounts may often be more accurate than those Johnson used to call up herself. Johnson doesn’t use modern technology much, but like the rest of us she is a cyborg. As the Johnsons headed home, through Princeton’s wooded streets, Lonni Sue stared downward, riffling through her grids, like a teen looking at Facebook.

An Artist with Amnesia (Via The New Yorker)