Saccadic eye movements (rapid movements of the eye as it jumps from one fixation point to another) take around one hundred and sixty milliseconds to program internally, and occur at the rate of around three per second, so that they occupy only some ten percent of viewing time. Under some conditions of viewing pictures, approximately thirty percent of viewing time is thought to be occupied by saccadic eye movements that go around and around the same (typically) ten fixations--to compose a scanpath of a duration of three to five seconds. The remainder of the viewing time is occupied with less regular eye movements.
It is from the reiterations of a scanpath that what has been called a feature ring or network is formed, a sequence of sensory and motor memory traces that alternatively record a feature of the object and the eye movement required to reach the next feature on the ring. In effect, a large proportion of viewing time concentrates on a very small number of targets. (No wonder that certain features in Bonnard's works can remain undetected for so long.) The smallness of the number of targets on a scanpath appears to be attributable to the fact that short-term (immediate) memory can only store between five and nine independent items. Although memory is usually thought of as applying to the past and sense perception as applying to the present, the creation of a scanpath, then a feature, is literally the creation of a memory. Thus, Bonnard paints from memory, paintings that, representing perception, represent the creation of memory.
Return to the glossary of terms
| ©1998 The Museum of Modern Art, New York |
 |