Beran Michael J, Beran Mary M, Menzel Charles R
Language Research Center, Georgia State University, 3401 Panthersville Road, Decatur, GA 30034, USA.
Primates. 2005 Oct;46(4):255-9. doi: 10.1007/s10329-005-0150-z. Epub 2005 Aug 10.
Four chimpanzees (Pan troglodytes) monitored the movement of hidden items in arrays of opaque cups. A chocolate candy was hidden in an array of four cups and temporarily presented paper markers indicated the location of the candy (which otherwise was not visible). These markers were either non-symbolic or symbolic (lexigram) stimuli that in other contexts acted as a label for the hidden candy, and the array was either rotated 180 degrees after the marker was removed or the array remained in the same location. For three of four chimpanzees, performance was better than chance in all conditions and there was no effect of the type of marker. These experiments indicate that chimpanzees can track the movement of a hidden item in an array of identical cups even when they never see the item itself, but only see a temporarily presented marker for the location of that item. However, there was no benefit to the use of symbolic as opposed to non-symbolic stimuli in this performance.
四只黑猩猩（黑猩猩属）监测不透明杯子阵列中隐藏物品的移动。一颗巧克力糖果被藏在四个杯子的阵列中，临时出示的纸质标记指示了糖果的位置（否则糖果是看不见的）。这些标记要么是非符号性的，要么是符号性的（词符）刺激，在其他情境中可作为隐藏糖果的标签，并且在移除标记后，阵列要么旋转180度，要么保持在同一位置。对于四只黑猩猩中的三只，在所有条件下的表现都优于随机水平，并且标记类型没有影响。这些实验表明，即使黑猩猩从未看到物品本身，而只看到该物品位置的临时出示标记，它们也能追踪相同杯子阵列中隐藏物品的移动。然而，在这种表现中，使用符号性刺激而非非符号性刺激并没有优势。
