Visual phenomena and multi-stability
In Experimental Phenomenology, Ihde has chosen to conduct phenomenological explorations of
visual phenomena, investigating a number of multi-stable visual phenomena. A multi-stable phenom-
enon can be perceived in two or several alternating appearances, such as the Danish psychologist
Rubin’s well-known drawing, which can be perceived as a vase or as two faces. Each appearance is
only stable for a while, then another gestalt stands out. In a progression of systematic step-by-step
investigations, Ihde demonstrates how deliberate variation of perception can reveal or provoke unno-
ticed appearances of multi-stable drawings. He demonstrates two strategies for variations.
One strategy is the focusing strategy.^37 Ihde’s example is a drawing, Figure 2.1, where lines appear
to be curved, even if they in reality are strict and parallel (p. 82-84)
Figure 2.1. Visual multi-stability: The focusing strategy. (Ihde 1977:82)
Reproduced by permission from Experimental Phenomenology by Don Ihde,
the State University of New York Press ©1986, State University of New York. All rights reserved.
The perceptual experiment consists of focusing on the vertex, where all the diagonal lines converge
in the center of the figure, and deliberately push this point back into infinity. By this concentrated
focusing, which may call for some exercise, the curved lines will appear straight. The modification of
focus is a modification of noetic shape (p. 87).
The other strategy is the hermeneutical strategy. Ihde’s example is another familiar multi-stable
drawing, the figure of a cube which can reverse itself into two different appearances, so that the front
side becomes the back side and vice versa (Figure 2.2).This reversal seems to occur spontaneously.
37 The term ”focusing strategy” is the author’s suggestion. Ihde’s term is ”transcendental strategy”, a more philosophical
term which indicates that this strategy concerns the conditions of possibility of perception (p. 89)