A stimulus display was devised that enabled us to examine how
effectively monkeys and humans can process shading and disparity cues for
depth perception. The display allowed us to present these cues separately,
in concert and in conflict with each other. An oddities discrimination
task was used. Humans as well as monkeys were able to utilize both shading
and disparity cues but shading cues were more effectively processed by
humans. Humans and monkeys performed better and faster when the two cues
were presented conjointly rather than singly. Performance was
significantly degraded when the two cues were presented in conflict with
each other suggesting that these cues are processed interactively at
higher levels in the visual system. The fact that monkeys can effectively
utilize depth information derived from shading and disparity indicates
that they are a good animal model for the study of the neural mechanisms
that underlie the processing of these two depth cues.