Improvement in human vision under bright light: grain or gain?
Improvement in human vision under bright light: grain or gain?
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强光下人类视力的改善：谷物还是增益？
DOI：
10.1113/jphysiol.1987.sp016859
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Stockman,A
中科院分区：
文献类型：
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作者：
Chen,B;MacLeod,DI;Stockman,A
1.当测试闪光较小时，增量阈值随背景强度变化的系数比较大时要小。这通常归因于随着光适应能力的增强，整合视觉信号的区域减少。2.我们提出并验证了另一种假设，即斜率的变化是纯粹局部过程的结果：如果假设增加背景强度会增加局部响应函数的指数，但不改变空间积分的程度，则小测试闪光的阈值将比大测试闪光的阈值上升得更慢，这仅仅是因为小测试闪光的强度高于大测试闪光，从而引起相应更大的局部响应。3.测量了小的和大的测试场增量阈值和双分辨亮度匹配作为背景强度的函数。4.小场增量阈值函数与大场增量阈值函数的对数斜率相差不超过20%，这表明即使在常规的数据解释下，空间积分的变化也比通常假设的要小。5.与另一只眼的标准匹配的大(2.3°)阈值上测试场的强度随背景强度的增加而变化，与小测试(2.6min)阈值与强度函数的浅斜率相同；这与局部非线性假说的预测一致，表明在光适应过程中空间整合没有实质性变化。
1. The factor by which increment threshold changes with changing background intensity is less if the test flash is small than if it is large. This is commonly attributed to a reduction of the area over which visual signals are integrated as light adaptation increases. 2. We propose and test an alternative hypothesis that the change in slope is the result of purely local processes: if it is assumed that increasing the background intensity increases the exponent of the local response function, but does not alter the extent of spatial integration, then the threshold of the small test flash will rise more slowly than the threshold of the large test flash simply because the small test flash is of a higher intensity than the large and therefore evokes a correspondingly greater local response. 3. We measured small and large test field increment thresholds and dichoptic brightness matches as a function of background intensity. 4. The log‐log slopes of the small and large field increment threshold functions differed by not more than about 20%, suggesting that even under the conventional interpretation of such data, the change of spatial integration is less than is usually supposed. 5. The intensity of a large (2.3 deg) suprathreshold test field matched to a standard in the other eye varies with increasing background intensity with the same shallow slope as the small test (2.6 min) threshold versus intensity function; this is in agreement with the predictions of the local non‐linearity hypothesis and suggests that there is no substantial change in spatial integration during light adaptation.