Lippolis Giuseppe, Westman Wendy, McAllan Bronwyn M, Rogers Lesley J
University of New England, Armidale, NSW, Australia.
Laterality. 2005 Sep;10(5):457-70. doi: 10.1080/13576500442000210.
Although lateralisation has been observed in many vertebrate species, marsupials have been neglected in the study of lateralisation. We investigated the behavioural responses of the stripe-faced dunnart (Sminthopsis macroura) to a mechanical model of a snake approaching into the monocular (left and right) or the binocular visual field. The snake model was presented to 30 adult subjects. The behavioural responses and the latency to react to the stimulus were scored. Reactivity was calculated by pooling scores for retreat, startle, ears back, and orientation. Retreat tended to be the most common of these responses. Approach of the snake into the dunnarts' left monocular visual field elicited a significantly higher reactivity compared to approach into the right or binocular visual field. Half of the animals did not respond in the 60 seconds allocated when the stimulus approached on their right side, whereas only seven did not respond when the stimulus approached on the left, and ten when the stimulus was presented binocularly. These results are consistent with the right hemisphere's known specialisation for controlling fear and escape responses. Our results suggest that marsupials are lateralised in a way similar to other vertebrates.
尽管在许多脊椎动物物种中都观察到了偏侧化现象，但有袋动物在偏侧化研究中一直被忽视。我们研究了带纹袋鼬（Sminthopsis macroura）对一条接近单眼（左和右）或双眼视野的蛇的机械模型的行为反应。将蛇模型展示给30只成年个体。对行为反应和对刺激做出反应的潜伏期进行评分。通过汇总退缩、惊吓、耳朵后翻和定向的分数来计算反应性。退缩往往是这些反应中最常见的。与进入右单眼或双眼视野相比，蛇进入袋鼬的左单眼视野引发的反应性明显更高。当刺激从右侧接近时，一半的动物在分配的60秒内没有反应，而当刺激从左侧接近时只有7只没有反应，当刺激双眼呈现时则有10只没有反应。这些结果与右半球控制恐惧和逃避反应的已知特化相一致。我们的结果表明，有袋动物的偏侧化方式与其他脊椎动物相似。
