Forest Before Trees: The Precedence of Global Features in Visual Perception

This experiment is based on the following paper:

Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383. Reprinted by permission from Academic Press.

In this study Navon introduced a new paradigm to examine how the visual system processes information. He posed the problem this way:

Do we perceive a visual scene feature-by-feature? Or is the process instantaneous and simultaneous as some Gestalt psychologists believed? Or is it somewhere in between? The Gestaltists’ view of the perceptual system as a perfectly elastic device that can swallow and digest all visual information at once, no matter how rich it is, is probably too naive. There is ample evidence that people extract from a picture more and more as they keep looking at it. But does this mean that interpreting the picture is done by integrating information collected in a piecemeal fashion? Is the perceptual whole literally constructed out of the percepts of its elements? (p. 353)

Navon hypothesized that visual perception is organized over time with the global shape of a visual scene processed first, followed by the analysis of the fine-grained visual details. Each scene is “in a process of being focused or zoomed in on, where at first it is relatively indistinct and then it gets clearer and sharper.” (p.354)


The full text describing the experiment is available here.

The experiments are available below. (27.1 KB) (33.5 KB)