Suppression pathways saturate with contrast for parallel surrounds but not for superimposed cross-oriented masks
Suppression pathways saturate with contrast for parallel surrounds but not for superimposed cross-oriented masks
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DOI：
10.1016/j.visres.2009.09.006
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发表时间：
2009-12-10
期刊：
影响因子：
1.8
通讯作者：
Baker, Daniel H.
中科院分区：
文献类型：
--
作者：
Meese, Tim S.;Challinor, Kirsten L.;Baker, Daniel H.
平行栅围(甜甜圈)掩模和叠加正交掩模具有不同的特点。然而，对于平行的甜甜圈掩模，已发现的潜在抑制的饱和度是否取决于(I)相对掩模和目标方向，(Ii)刺激偏心或(Iii)环绕抑制，目前尚不清楚。我们测量了中心凹和外围交叉定向重叠和环状掩模以及平行环状掩模的目标格栅斑块的对比度掩蔽函数。当抑制明显时，决定它是加速还是饱和的因素是掩蔽刺激是交叉的还是平行的。对于平行环绕掩模的渐近行为，至少有两种解释。(I)抑制来自充满(掩蔽)对比度的通路。(2)目标由在低目标对比度时受到环绕抑制的机制来处理，但在较高目标对比度时不受环绕抑制影响的较不敏感的机制来处理目标。如果掩码的效力可以降低，那么两个账户的掩码函数应该分别向下和横向移动。我们通过改变平行的甜甜圈面具上的孔的大小来操纵面具的效力。这些结果为第一种说法提供了强有力的证据，但不支持第二种说法。鉴于反应压缩随着视觉通路的进展而变得更加严重的观点，我们的结果表明，叠加的交叉定向抑制先于定向调节的环绕抑制。这些结果还揭示了以前未被认识到的环绕抑制和拥挤之间的相似性(Pelli，Palomares，&Majaj，2004)。(C)2009爱思唯尔有限公司。保留所有权利。
Contrast masking from parallel grating surrounds (doughnuts) and superimposed orthogonal masks have different characteristics. However, it is not known whether the saturation of the underlying suppression that has been found for parallel doughnut masks depends on (i) relative mask and target orientation, (ii) stimulus eccentricity or (iii) surround suppression. We measured contrast-masking functions for target patches of grating in the fovea and in the periphery for cross-oriented superimposed and doughnut masks and parallel doughnut masks. When suppression was evident, the factor that determined whether it accelerated or saturated was whether the mask stimulus was crossed or parallel. There are at least two interpretations of the asymptotic behaviour of the parallel surround mask. (I) Suppression arises from pathways that saturate with (mask) contrast. (2) The target is processed by a mechanism that is subject to surround suppression at low target contrasts, but a less sensitive mechanism that is immune from surround suppression 'breaks through' at higher target contrasts. If the mask can be made less potent, then masking functions should shift downwards, and sideways for the two accounts, respectively. We manipulated the potency of the mask by varying the size of the hole in a parallel doughnut mask. The results provided strong evidence for the first account but not the second. On the view that response compression becomes more severe progressing up the visual pathway, our results suggest that superimposed cross-orientation suppression precedes orientation tuned surround suppression. These results also reveal a previously unrecognized similarity between surround suppression and crowding (Pelli, Palomares, & Majaj, 2004). (C) 2009 Elsevier Ltd. All rights reserved.