Lohmann Annette, Delius Juan D, Hollard Valerie D, Friesel Maria F
Ruhr-U Bochum.
J Comp Psychol. 1988 Mar;102(1):3-13. doi: 10.1037/0735-7036.102.1.3.
By using a free-operant instrumental discrimination procedure, it was demonstrated that pigeons find two-dimensional mirror-image visual forms more difficult to distinguish than otherwise similar forms. Variations in orientation of the discriminanda exacerbated the relative confusability of mirror images. No significant difference was found in the pigeons' performance whether the birds were discriminating vertically or horizontally reflected mirror-image pairs. Mirror images of shapes were also shown to be less discriminable than upside-down versions of shapes. The similarity of mirror-image patterns is discussed in relation to the generalized recognition of bilaterally symmetrical forms by pigeons. Pigeons found an orientation discrimination task involving a 45 degree tilt comparatively hard. A second experiment with a discrete-trial conditional paradigm confirmed that discriminations of shape orientations can be difficult for these birds. The addition of shape cues improved the performance on the orientation discrimination task, more so when arbitrary shapes were employed than when mirror images were used, which indicates again that the latter were more difficult to discriminate than the former. The relative insensitivity to shape orientations is ascribed to normal ecological demands on pigeons.
通过使用自由操作的工具性辨别程序，结果表明，鸽子发现二维镜像视觉形式比其他类似形式更难区分。辨别刺激物方向的变化加剧了镜像的相对混淆性。无论鸽子是辨别垂直还是水平反射的镜像对，其表现均未发现显著差异。形状的镜像也比形状的倒置版本更难辨别。结合鸽子对双侧对称形式的广义识别，讨论了镜像图案的相似性。鸽子发现涉及45度倾斜的方向辨别任务相对困难。另一个采用离散试验条件范式的实验证实，这些鸟类对形状方向的辨别可能会很困难。形状线索的添加提高了方向辨别任务的表现，使用任意形状时比使用镜像时提高得更多，这再次表明后者比前者更难辨别。对形状方向的相对不敏感归因于鸽子正常的生态需求。
