Natural selection tends to foster simple, elegant biological solutions that do not waste metabolic energy. Ramachandran, Churchland and Sejnowski (1994: 36-37) contend that we do not “create and maintain a visual world representation that corresponds detail-by-detail to the visual world itself.” This would be unnecessary since “the world itself is highly stable and conveniently “out there’ to be sampled and resampled. Eye-tracking experiments “elegantly support” their “partial representation per glimpse” hypothesis.

Robotocist Andy Clark, who champions the notion of "mind on the hoof," explains (1998: 31) how text reading experiments are performed:

The target text is never all present on the screen at once. Instead, the real text is restricted to a display of (for typical subjects) 17 or 18 characters. This text is surrounded by junk characters which do not form real words. But (and here is the trick) the window of real text moves along the screen as the subject’s eyes scan from left to right…When such a system is well calibrated to an individual subject, the subject does not notice the presence of the junk!

Daniell C Dennett recalls (1991: 361) his first encounter with an eye-tracker experiment:

As you peruse the text on the screen, it seems to you for all the world as stable as if the words were carved in marble, but to another person reading the same text over your shoulder (and saccading to a different drummer) the screen is aquiver with changes...

While I waited, and waited, eager for the trials to begin. I got impatient. “Why don’t you turn it on?” I asked. “It is on,” they replied.

Patricia Churchland, V. S. Ramachandran, Terrance Sejnowski (1994). A Critique of Pure Vision, in Large-Scale Neuronal Theories of the Brain, edited by Christof Koch and Joel Davis, MIT Press, 1994.

Clark, Andy (1998) Being There: Putting Brain, Body, and World Together Again. A Bradford Book The MIT Press. Cambridge, Massachusetts.

Dennett C. Dennett (1991 ) Consciousness Explained. Little Brown and Company, Boston, London and Toronto.