Kilian A, von Fersen L, Güntürkün O
Tiergarten Nürnberg, Am Tiergarten 30, 90480, Nürnberg, Germany.
Behav Brain Res. 2000 Dec 5;116(2):211-5. doi: 10.1016/s0166-4328(00)00273-4.
Two adult female bottlenose dolphins were tested for cerebral asymmetries in the visuospatial domain. The animals learned under binocular conditions a three-choice spatial discrimination task with three hoops positioned along a line in the middle of the tank. During a correct trial the dolphins had to swim from a starting position at the tanks wall through one of the hoops, come back to the starting position, choose another hoop, swim back to start and finally swim through the third hoop. For such a trial to be correct, the animals had to swim through all three hoops in any sequence without omitting or re-using one of them. After reaching criterion binocularly, monocular trials (one eye covered with an adherent suction cup) were introduced where the dolphins carried out the same task alternatingly under left or right eye seeing conditions. For both animals, the right eye performance was clearly superior to that of the left eye. Binocular and right eye performances were similar. As a result of the complete decussation at the optic nerve, this right eye superiority suggests a left-hemispheric dominance for the processing of visuospatial information. This is a remarkable deviation from the usual right hemisphere advantage for these kind of tasks found in different species of mammals and birds.
对两只成年雌性宽吻海豚进行了视觉空间领域大脑不对称性的测试。这些动物在双眼条件下学习一项三选空间辨别任务，在水箱中间沿一条线放置三个箍。在一次正确的试验中，海豚必须从水箱壁的起始位置游过其中一个箍，回到起始位置，选择另一个箍，游回起始位置，最后游过第三个箍。要使这样一次试验正确，动物必须按任何顺序游过所有三个箍，不能遗漏或重复使用其中一个。在双眼达到标准后，引入单眼试验（一只眼睛用附着的吸盘覆盖），海豚在左眼或右眼视物条件下交替执行相同任务。对两只动物来说，右眼的表现明显优于左眼。双眼和右眼的表现相似。由于视神经完全交叉，这种右眼优势表明在视觉空间信息处理方面左半球占主导地位。这与在不同种类的哺乳动物和鸟类中发现的此类任务通常右半球优势明显不同。
