phenomenon exemplified the new attitude towards perception that Crary de-
scribes. The way afterimages were described and the role they played within
the optical devices known as philosophical toys, which produced moving
images, vividly reveals the assumptions generated and the tensions raised by
the moving image in this new intellectual and technological context.
Contemporary perceptual psychologist R.L. Gregory defines afterimages (of
which there are both positive and negative types) as“the continuing firing of
the optic nerve after the stimulation”.In other words, after an object has been
removed from the field of vision an image of it lingers, due, in Gregory’s expla-
nation, to a physical process within the retina, especially if the object were
bright or the gaze fixated. By means of an afterimage we paradoxically see an
object even in its absence. This phenomenon had been observed for centuries,
including discussions by Aristotle, Ptolemy, Ibn al Haytham and Leonardo da
Vinci.The afterimage forms the most dramatic example of what are often
called“subjective visual phenomenon”, i.e. seeing images that result from a
bodily response rather than from a“sampling”of the world. Studying and de-
monstrating this phenomenon led to the first proliferation of optical philosophi-
cal toys. As Crary puts it,“beginning in the mid-s, the experimental study
of afterimages led to the invention of a number of related optical devices and
techniques.”These devices announced the invention of modern motion pic-
tures and popularized the concept of the persistence of vision as the means of
creating an illusion of apparent motion.
“The persistence of vision”exemplifies the nineteenth century’s understand-
ing of visual illusions as primarily a physiological phenomenon, which can be
demonstrated, triggered and even measured through mechanical and optical
devices. Few concepts have been evoked so often in relation to visual devices
and especially moving images, and yet so disputed as this one. As an explana-
tion of the phenomenon of apparent motion it has now basically been dis-
carded, but still must be dealt with as a revealing historical and cultural legacy
(and one that displays its own phantom persistence, as perceptual psychologists
like Joseph and Barbra Anderson have lamented).As Mary Ann Doane has put
it“The theory of persistence of vision may be“wrong”, but the question re-
mains–why was it so firmly ensconced and what function did it serve in the
th century?”The attitude toward vision maintained by the persistence of
vision thesis, reveals the interface nineteenth century scientists thought they
had discovered (and in many senses hadmanufactured) between human percep-
tion and the machine. The attraction of the theory for the nineteenth century, I
believe lies largely in its essentially mechanical view of the human sensorium
(and its persistence in some accounts of cinema to this date indicates how much
a mechanical view of perception and cognition still underlies the assumptions
most people maintain about vision). Persistence of vision and the optical de-
28 Tom Gunning