FURTHER EVIDENCE FOR MONOCULAR DETERMINANTS OF PERCEIVED PLAID DIRECTION

This report adds to existing evidence that a monocular, feature-sensit ive motion mechanism is involved in two-dimensional (2-D) motion proce ssing, and also accounts for an earlier, unexplained result [Alais et al.(1994) Vision Research, 34, 1823-1834], The central finding is that the perceived direction of a monocularly viewed type II plaid changes over a period of continuous exposure such that post-adaptation direct ion judgements exhibit more of the component-direction bias known to o ccur with these stimuli than pre-adaptation judgements, These adaptati on effects are confined to the adapted eye: when the adapting stimulus is presented to one eye, pre- and post-adaptation direction judgement s made with the other, non-adapted eye are identical, These results st rongly suggest the involvement of a monocular motion mechanism in two- dimensional motion processing, in addition to the more commonly presum ed binocular mechanisms.