Cue-dependent and cue-invariant mechanisms in perception and perceptual learning

This study consists of two parts related to perceptual learning and perception respectively. In the first part, we examined visual learning at multiple levels of the visual system: the one that depends on and the one that is invariant to cues used to define the stimulus. The results of four experiments on visual discrimination are reported. Taken as a whole, these experiments strongly support the hypothesis that cue-invariant mechanisms mediate the transfer of learning from familiar cue conditions to novel cue conditions, thereby allowing perceptual learning to be robust and efficient. The results also support the idea that visual learning takes place at multiple levels of the human visual system. We conclude that a comprehensive understanding of visual perception will require a good understanding of learning at each of these levels. The second part of the study examines the role of cue-invariant and cue-dependent mechanisms in the context of cue combination. The results of two experiments show that subjects' performance in slant discrimination is affected by shape information. This result is consistent with the hypothesis that slant judgments take advantage of cue-invariant representation of shape. The implications for modeling cue integration are discussed.