yarbus

This time the same subject was asked to remember what the the people were wearing

Before this scan the same subject was asked to estimate the ages of the people

In this scan the subject was allowed to examine Repin's painting freely.

Ilya Repin. The Unexpected Return. 1884. Oil on canvas. The Tretyakov Gallery, Moscow, Russia.

Russian psychologist Alfred L. Yarbus investigated the nature of eye movements in the fifties and sixties. His eye tracking experiments revealed that subjects viewing complex scenes utilize saccadic jumps between points of most interest.

Yarbus showed that eye balls do not scan in raster (rake-like) sweeps. We do not move our eyes at all like TV or radar screens. Rather we scan actively and freely for points of interest. This involves more than targeting the fovea on main lines, contours and points of contrast to somehow take in a compostion in the abstract. Between saccades we fixate on objects of biological and experiential significance. Faces in particular, especially mobile eyes and mouths, demand our attention. According to Yarbus (1967):

[H]uman eyes voluntarily and involuntarily fixate on those elements of a visual scene that carry essential and useful information. The more information is contained in an element, the longer the eyes stay on it. The distribution of fixations on the elements of a scene changes depends on the purpose of the observer, i.e., it is determined by information to be obtained and the thought process accompanying the analysis of this information. Hence people who think differently also, to some extent, see differently.

A. L. Yarbus (1067) Eye Movements and Vision. New York: Plenum Press (Translated from the 1965 Russian edition by Basil Haigh.)