Schusterman R J
Science. 1967 May 12;156(3776):833-5. doi: 10.1126/science.156.3776.833.
Repeated combinations of a previously well-learned size clue preference with the previously negative form cue followed by gradual reduction of the size cue resulted in nearly errorless performance by two sea lion. on a series of nine form-discriminination reversals. Systematic insertion of probe trials, during which the size cue was not present, revealed that attention was primarily focused on the size dimension during early stages of training, when size differences were large, and then was gradually shifted to the form dimension as a function of the increasing difficulty of the size discrimination.
将先前熟练掌握的大小线索偏好与先前的负面形状线索反复组合，随后逐渐减少大小线索，结果两只海狮在一系列九次形状辨别反转任务中表现几乎无误。系统地插入探测试验（在此期间不存在大小线索）表明，在训练早期，当大小差异较大时，注意力主要集中在大小维度上，然后随着大小辨别难度的增加，注意力逐渐转移到形状维度上。
