The lines scribbled over this famous Georges Seurat painting come from an experiment that tracked how the human eye jerks around as it takes in the details of the scene. (Credit: R. Wurtz / Daedalus 2015 / Public Domain)

The image above, “A Sunday Afternoon on the Island of La Grande Jatte,” was painted in 1884 by French artist Georges Seurat. The black lines crisscrossing it are not the work of a toddler wreaking havoc with a permanent marker, but that of neuroscientist Robert Wurtz of the