Watanabe Shigeru
Department of Psychology, Keio University, Tokyo, Japan.
Front Psychol. 2020 Jul 16;11:1350. doi: 10.3389/fpsyg.2020.01350. eCollection 2020.
Japanese eels () were trained on a spatial-learning paradigm in a pool placed in an experimental room where several extra-maze cues were present. Four tubes were placed in the pool, of which one was open and could be entered by the eels. The open tube was placed at a fixed position in the pool and contained a triangular block that served as an intra-maze cue. The eels learned to identify the open tube, and their performance was maintained when the pool was rotated. However, they were unable to maintain their performance in a dark room, which suggests that spatial learning is based on visual cues. To determine the influence of the extra- and intra-maze cues, the tube with the triangle was moved to a new position and another open tube was kept in its place. The eels chose either the tube at the original position or the tube with the triangle at its new position, suggesting that spatial discrimination may be based on either extra- or intra-maze cues. We thus conclude that the eels employed an adjunctive strategy of multiple cues. In the next experiment, the eels were trained to visually discriminate the position of the stimulus (triangle), which changed in every trial. After the training, the eels were submitted to a test in which, in addition to the triangular pattern, a rectangular pattern was introduced. The eels discriminated between the tubes with the triangular and rectangular patterns, suggesting that they had the ability to discriminate visual patterns.
日本鳗鲡在放置于有多个迷宫外部线索的实验室内的水池中，接受空间学习范式训练。水池中放置了四根管子，其中一根是开放的，鳗鱼可以进入。开放的管子放置在水池中的固定位置，里面有一个三角形块作为迷宫内部线索。鳗鱼学会了识别开放的管子，并且当水池旋转时它们的表现得以维持。然而，它们在黑暗的房间里无法维持其表现，这表明空间学习是基于视觉线索的。为了确定迷宫外部和内部线索的影响，将带有三角形的管子移到一个新位置，并在其位置保留另一个开放的管子。鳗鱼要么选择原来位置的管子，要么选择三角形在新位置的管子，这表明空间辨别可能基于迷宫外部或内部线索。因此，我们得出结论，鳗鱼采用了多种线索的辅助策略。在下一个实验中，训练鳗鱼从视觉上辨别每次试验中位置都会改变的刺激物（三角形）的位置。训练后，对鳗鱼进行测试，除了三角形图案外，还引入了矩形图案。鳗鱼能够区分带有三角形和矩形图案的管子，这表明它们具有区分视觉图案的能力。
