Castro Leyre, Wasserman Edward A
The University of Iowa, Iowa City, IA 52242, United States.
Behav Processes. 2010 Feb;83(2):162-71. doi: 10.1016/j.beproc.2009.10.007. Epub 2009 Nov 10.
In two experiments, we explored the effects of varying the size and the spatial organization of the stimuli in multi-item arrays on pigeons' same-different discrimination behavior. The birds had previously learned to discriminate a simultaneously presented array of 16 identical (Same) visual items from an array of 16 nonidentical (Different) visual items, when the correct choice was conditional on the presence of another cue: the color of the background (Castro et al., in press). In Experiment 1, we trained pigeons with 7-item arrays and then tested them with arrays containing the same item, but in a variety of sizes. In Experiment 2, we tested the birds with the items grouped in novel locations: the top, the bottom, the left, or the right portions of the display area, which generated different vertical and horizontal alignments. Accuracy scores revealed virtually perfect stimulus generalization across various item sizes and spatial organizations. Reaction times revealed that the birds perceived different sizes of a single icon as the same stimulus (Experiment 1) and that the birds processed vertical arrangements faster than horizontal arrangements (Experiment 2). These results suggest that the pigeons noticed both physical and spatial changes in the stimuli (as shown by their reaction times), but that these changes did not disrupt the birds' discriminating the sameness or differentness of the multi-item arrays (as shown by their accuracy scores).
在两项实验中，我们探究了改变多项目阵列中刺激物的大小和空间组织对鸽子异同辨别行为的影响。这些鸽子之前已经学会，当正确选择取决于另一个线索（背景颜色）时，从16个不同（不同）视觉项目的阵列中辨别出同时呈现的16个相同（相同）视觉项目的阵列（卡斯特罗等人，即将发表）。在实验1中，我们用7个项目的阵列训练鸽子，然后用包含相同项目但大小各异的阵列对它们进行测试。在实验2中，我们用在新位置分组的项目对鸽子进行测试：显示区域的顶部、底部、左侧或右侧部分，这会产生不同的垂直和水平排列。准确率得分显示，在各种项目大小和空间组织中，刺激泛化几乎是完美的。反应时间显示，鸽子将单个图标的不同大小视为相同刺激（实验1），并且鸽子处理垂直排列的速度比水平排列快（实验2）。这些结果表明，鸽子注意到了刺激物的物理和空间变化（如它们的反应时间所示），但这些变化并没有干扰鸽子对多项目阵列的异同辨别（如它们的准确率得分所示）。
