INTERACTIONS BETWEEN GLOBAL MOTION AND LOCAL BINOCULAR-RIVALRY

Binocular rivalry is thought to arise from a low-level cortical site. Experiment 1 evaluates this claim with respect to local and global mot ion processing by using a multiple-aperture motion stimulus and measur ing the predominance of global coherence while one of the component gr atings is engaged in rivalry, Results show that rivalry suppression of the component grating precludes global coherence, Presumably, suppres sion prevents the component motion signal from advancing to higher-lev el global motion areas, suggesting rivalry occurs between local and gl obal motion processing, However, feedback from higher-level mechanisms might exert an influence on binocular rivalry and thus Experiment 2 m easures how the predominance of a local target engaged in binocular ri valry with a competing local stimulus is affected when the target form s part of a globally coherent motion stimulus, The augmented level of target predominance during global motion relative to local motion indi cates that higher-level motion mechanisms can feedback and influence t he binocular rivalry process, Together, these data imply a looping hie rarchy of motion processing stages, with rivalry suppression transpiri ng at an intermediate level and subject to feedback from higher-level motion areas, (C) 1998 Elsevier Science Ltd, All rights reserved.