Dualistic Versus Monistic Accounts of Lightness Perception

Conclusions

Our inability to explain in concrete terms how lightness is computed by the visual system has left us with an uneconomical and unfalsifiable dual explanation, attributing some aspects of lightness to bodily processes and others to mental processes. The failure of low-level accounts based on contrast mechanisms to cope with either the results of lightness constancy work in 3D displays or the new wave of configuration-based lightness illusions has led to a renewed interest in a dual high-low account. But this retreat is not necessary. The feasibility of a coherent monistic account was shown by Gestalt theory early in this century, and recent work on lightness anchoring has extended this approach and made it more concrete. Indeed, in a recent series of experiments testing variations on simultaneous contrast, the anchoring approach was shown to make specific predictions while the low-level account did not.