Lacey Simon, Pappas Marisa, Kreps Alexandra, Lee Kevin, Sathian K
Department of Neurology, School of Medicine, Emory University, WMB-6000, Atlanta, GA 30322, USA.
Exp Brain Res. 2009 Sep;198(2-3):329-37. doi: 10.1007/s00221-009-1856-8. Epub 2009 May 31.
We previously showed that cross-modal recognition of unfamiliar objects is view-independent, in contrast to view-dependence within-modally, in both vision and haptics. Does the view-independent, bisensory representation underlying cross-modal recognition arise from integration of unisensory, view-dependent representations or intermediate, unisensory but view-independent representations? Two psychophysical experiments sought to distinguish between these alternative models. In both experiments, participants began from baseline, within-modal, view-dependence for object recognition in both vision and haptics. The first experiment induced within-modal view-independence by perceptual learning, which was completely and symmetrically transferred cross-modally: visual view-independence acquired through visual learning also resulted in haptic view-independence and vice versa. In the second experiment, both visual and haptic view-dependence were transformed to view-independence by either haptic-visual or visual-haptic cross-modal learning. We conclude that cross-modal view-independence fits with a model in which unisensory view-dependent representations are directly integrated into a bisensory, view-independent representation, rather than via intermediate, unisensory, view-independent representations.
我们之前表明，与视觉和触觉中模态内的视角依赖性不同，对不熟悉物体的跨模态识别是视角独立的。跨模态识别背后的视角独立的双感觉表征是源于单感觉的、视角依赖的表征的整合，还是源于中间的、单感觉但视角独立的表征呢？两项心理物理学实验试图区分这些替代模型。在这两项实验中，参与者在视觉和触觉中对物体识别都从基线的模态内视角依赖性开始。第一个实验通过知觉学习诱导模态内视角独立性，这种独立性以完全对称的方式跨模态转移：通过视觉学习获得的视觉视角独立性也会导致触觉视角独立性，反之亦然。在第二个实验中，视觉和触觉的视角依赖性通过触觉 - 视觉或视觉 - 触觉跨模态学习都转变为视角独立性。我们得出结论，跨模态视角独立性符合这样一种模型，即单感觉的视角依赖表征直接整合为双感觉的、视角独立的表征，而不是通过中间的、单感觉的、视角独立的表征。
