Livne Tomer, Sagi Dov
Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
J Vis. 2011 Nov 18;11(13):18. doi: 10.1167/11.13.18.
Using oriented Gabor patches, we found that for nearly cardinal target orientations, oblique flankers' orientations induced more interference than did cardinal flankers' orientations. This pattern was observed both at the local and global levels of flankers' orientation. With respect to the global orientation (flankers' global arrangement around the target), there was no difference between the effects of the two cardinal orientations, and both induced the same amount of interference. With respect to the local orientation (Gabors' orientation), in accordance with previous reports, a difference was found between the effects of the two cardinal orientations--a considerable amount of interference with flankers equal in orientation to the target (although less than with the oblique flankers) and almost no interference from flankers orthogonal to the target. Crowding was also affected by an anisotropy based on the target-fixation axis (radial, tangential, and diagonal) and by the flankers' relations. The magnitude of these latter factors was small relative to that of the former ones. The multiple factors that affected crowding, as well as the similarities and the differences between the effects at the two orientation levels, suggest that crowding is determined by multiple sources of interference operating at several levels of representation.
使用定向的伽柏补丁，我们发现，对于几乎呈主要方向的目标方向，倾斜侧翼的方向比主要侧翼的方向产生更多干扰。这种模式在侧翼方向的局部和全局层面均被观察到。关于全局方向（侧翼围绕目标的全局排列），两种主要方向的效果没有差异，且都产生相同程度的干扰。关于局部方向（伽柏的方向），与先前的报告一致，发现两种主要方向的效果存在差异——与目标方向相同的侧翼会产生相当程度的干扰（尽管比倾斜侧翼产生的干扰少），而与目标正交的侧翼几乎不产生干扰。拥挤效应还受到基于目标注视轴（径向、切向和对角线方向）的各向异性以及侧翼关系的影响。相对于前者，后两者因素的影响程度较小。影响拥挤的多个因素，以及两个方向层面效果之间的异同，表明拥挤是由在多个表征层面起作用的多种干扰源所决定的。
