Ambiguous perspective figure: 
the pattern can be seen either 
as a hallway (or box) or as a 
truncated pyramid.

    In our experiments, 
therefore, we say nothing about 
the potential re-versibility of 
the figure. We present either 
Rubin’s well-known figure of 
the vase and faces or the figure 
shown here. Then we ascertain 
how the figure is perceived, 
either by occasional samplings 
or by a careful interview after 
the period of presentation. By 
conducting experiments in this 
way, we have found that 
children under the age of 4 or 5 
never reverse spontaneously 
and only rarely and with 
difficulty do so when they are 
shown the alternative 
possibility. High-school 
students often do not reverse at 
all, and most continue to see 
whatever they perceive at the 
outset for up to a minute or so. 
The remainder may reverse 
once or, at most, a few times in 
the period—–a far cry from 
reversal every 5 or 10 seconds, 
the typical outcome using the 
traditional method. In fact, 
these same subjects will 
reverse frequently when later 
given the traditional 
instructions.

    These findings suggest that 
the satiation theory is 
incorrect or at best only one 
factor governing reversals. 
Satiation is presumably a 
process that is automatic and 
inexorable, given the stimulus 
presentation. Whether the 
subject knows that the figure 
can be reversed and what the 
specific alternatives are should 
have no influence on the 
process.