Mosley J L
Am J Ment Defic. 1978 Jan;82(4):380-5.
Two-letter stimulus displays, differing in the magnitude of the horizontal spatial separation between the letters, were presented tachistoscopically to retarded and nonretarded persons. Assuming that the spatial separations are linearly related to retinal location, I derived an estimate of the stimulus-recognition threshold for each group by employing the method of constant stimuli. The data indicated a similar stimulus-recognition threshold and a similar decrement in the accuracy of responding as the stimulus separations increased. These findings suggested that reported differences in iconic memory between retarded and nonretarded individuals are most likely related to a postretinal stage of cognitive processing. Studies of iconic memory must take into account not only the influence of retinal locus but also the finding that, as the task becomes more difficult, retarded individuals may be less willing to respond.
以速示器向智力迟钝者和非智力迟钝者呈现由两个字母组成的刺激显示，字母之间的水平空间间隔大小不同。假设空间间隔与视网膜位置呈线性关系，我采用恒定刺激法得出了每组的刺激识别阈值估计值。数据表明，随着刺激间隔增加，两组的刺激识别阈值相似，反应准确性的下降也相似。这些发现表明，报告的智力迟钝者和非智力迟钝者在图像记忆方面的差异很可能与认知加工的视网膜后阶段有关。对图像记忆的研究不仅必须考虑视网膜位置的影响，还必须考虑到随着任务变得更加困难，智力迟钝者可能更不愿意做出反应这一发现。
