Temporal resolution of orientation-based texture segregation
Temporal resolution of orientation-based texture segregation
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DOI：
10.1016/s0042-6989(01)00096-7
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发表时间：
2001-07-01
期刊：
影响因子：
1.8
通讯作者：
Nishida, S
中科院分区：
文献类型：
--
作者：
Motoyoshi, I;Nishida, S
我们分析了基于方向的纹理分离所涉及的两个功能过程的时频特性：局部方向编码和随后的方向对比度编码。两个纹理图像，其中每个微图案旋转90度，以不同的时间频率交替。微图案是高斯的二阶导数(D2)，当与正交D2图案在时间上融合时，该高斯丢失方向信息。我们测量了定位目标区域的时间-频率上限，该目标区域的平均取向与背景相差90度或45度。如果纹理感知的时间限制是由最慢的处理阶段确定的，则90度纹理的时间限制应该通过局部定向编码或定向对比度编码来确定，这取决于哪个阶段具有较低的时间精度。另一方面，无论定向对比度编码的时间限制如何，45度纹理应该始终被分离在局部定向编码的时间限制之下。我们发现，在适合于纹理分离的空间条件下，90度纹理的时间限制略高于45度纹理。此外，在较宽的时间频率范围内对偏析性能的取向噪声分析表明，两种织构的时间-频率敏感性几乎相同。这些结果表明，基于取向的纹理分离的时间限制仅取决于局部取向编码的时间限制。这一结论进一步表明，方位-对比度编码的潜在时间分辨率不低于局部方位编码，这意味着方位-对比度编码不太可能是由迟缓的神经过程介导的。(C)2001爱思唯尔科学有限公司。保留所有权利。
We analysed the temporal-frequency characteristics of two functional processes involved in orientation-based texture segregation: local orientation coding and subsequent orientation-contrast coding. Two texture images, in which each micropattern was rotated by 90 degrees, were alternated at various temporal frequencies. A micropattern was a second-derivative (D2) of a Gaussian that loses orientation information when temporally fused with the orthogonal D2 pattern. We measured the upper temporal-frequency limits for localising the target region whose mean orientation differed from the background by 90 degrees or by 45 degrees. If the temporal limit of the texture perception is determined by the most sluggish processing stage, the temporal limit for the 90 degrees texture should be determined by local orientation coding or by orientation-contrast coding, depending on which stage has the lower temporal precision. On the other hand, the 45 degrees texture should always be segregated below the temporal limit of local orientation coding regardless of the temporal limit of orientation-contrast coding. We found that the temporal limit for the 90 degrees texture was slightly higher than that for the 45 degrees texture under spatial conditions appropriate for texture segregation. Moreover, an orientation-noise analysis of segregation performance for a wide range of temporal frequencies revealed that the temporal-frequency sensitivities for the two textures were nearly identical. These results imply that the temporal limit for orientation-based texture segregation depends only on that of local orientation coding. This conclusion further suggests that the potential temporal resolution of orientation-contrast coding is not lower than that of local orientation coding, which would imply that the orientation-contrast coding is unlikely to be mediated by sluggish neural processes. (C) 2001 Elsevier Science Ltd. All rights reserved.