Hess Robert F, Wilcox Laurie M
McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Que., Canada.
Vision Res. 2006 Jun;46(12):1911-23. doi: 10.1016/j.visres.2005.12.007. Epub 2006 Feb 15.
The experiments reported here focus on the temporal dynamics of stereopsis in an effort to shed light on how low level mechanisms might contribute to the execution of coarse-to-fine processing in the human stereo system. Because previous studies have used a variety of stimuli and configurations, we assess the effect of exposure duration on stereo thresholds using band-limited Gabor patches for a range of stimulus configurations. In preliminary studies, we found that the best stereo sensitivity-spatial frequency relationship was obtained when using configurations in which the size and target-reference spacing were consistent with spatially scaled stimuli. Sub-optimal stereo sensitivity as a function of spatial frequency was observed when the size and separation were fixed. Further, we found that the temporal properties of stereopsis were consistently sustained in nature irrespective of the stimulus spatial frequency content. This latter finding suggests that if coarse-to-fine stereo processing does occur it does not follow as a consequence of the dynamics of low-level disparity transduction.
本文所报道的实验聚焦于立体视觉的时间动态,旨在阐明低级机制如何有助于人类立体视觉系统中从粗到细的处理过程。由于先前的研究使用了各种刺激和配置,我们使用带限高斯包络片针对一系列刺激配置评估暴露持续时间对立体视觉阈值的影响。在初步研究中,我们发现当使用尺寸和目标 - 参考间距与空间缩放刺激一致的配置时,可获得最佳的立体视觉灵敏度 - 空间频率关系。当尺寸和间距固定时,观察到作为空间频率函数的次优立体视觉灵敏度。此外,我们发现无论刺激的空间频率内容如何,立体视觉的时间特性在本质上都是持续的。后一发现表明,如果确实发生了从粗到细的立体视觉处理,它并非低级视差转导动态的结果。