Ishikawa Ayako, Shimegi Satoshi, Sato Hiromichi
Laboratory of Behavioral and Cognitive Neuroscience, Graduate School of Medicine, Osaka University, Toyonaka, Osaka 560-0043, Japan.
Vision Res. 2006 Jun;46(13):2130-8. doi: 10.1016/j.visres.2005.12.013. Epub 2006 Feb 15.
We examined the spatiotemporal characteristics of metacontrast using sinusoidal grating stimuli as the target and mask for quantitative comparison with the functional properties of the visual cortex. The magnitude of metacontrast effects depended on the stimulus features such as the orientation and spatial frequency of the target and mask. The characteristics of metacontrast dynamically changed depending on the stimulus onset asynchrony (SOA). At short SOAs (0 to approximately 40 ms), metacontrast exhibited a high stimulus feature specificity and a low contrast sensitivity, whereas at long SOAs ( approximately 40 to 80 ms), metacontrast exhibited a low stimulus feature specificity and a high contrast sensitivity. We suggest that metacontrast is explained by the interaction between two parallel visual pathways: one with a low contrast sensitivity and a high feature specificity, and the other with a high contrast sensitivity and a low feature specificity.
我们使用正弦光栅刺激作为目标和掩蔽来研究元对比的时空特性，以便与视觉皮层的功能特性进行定量比较。元对比效应的大小取决于刺激特征，如目标和掩蔽的方向和空间频率。元对比的特征会根据刺激起始异步性（SOA）动态变化。在短SOA（0至约40毫秒）时，元对比表现出高刺激特征特异性和低对比敏感度，而在长SOA（约40至80毫秒）时，元对比表现出低刺激特征特异性和高对比敏感度。我们认为元对比可以通过两条平行视觉通路之间的相互作用来解释：一条具有低对比敏感度和高特征特异性，另一条具有高对比敏感度和低特征特异性。
