Department of Biological & Marine Sciences, University of Hull, Cottingham Road, Hull HU6 7RX, UK.
Biol Lett. 2020 May;16(5):20190870. doi: 10.1098/rsbl.2019.0870. Epub 2020 May 13.
Laterality, the division of brain functions into separate hemispheres, is widespread across animal taxa. Lateralized individuals exhibit cognitive advantages yet substantial variation in laterality exists, particularly between the sexes. Why variation is maintained is unknown as few studies consider differences in lateralized behaviours between the sexes, and their underlying selection pressures, across different contexts. We investigated if exhibited sex differences in the direction, strength and consistency of lateralization. We assessed the turning preferences of individuals detouring around a barrier to view visual stimuli representative of different behavioural contexts: an artificial object of familiar colour, an opposite sex conspecific and a no stimulus control. While no sex differences were evident in the direction or strength of laterality, consistency in the strength of laterality varied between the sexes. Individuals of both sexes consistently detoured in one direction, but the strength of laterality exhibited by males was more predictable than females across contexts. This suggests that predictability of lateralization across ecologically relevant scenarios represents a key, but previously unexplored, source of variation between the sexes.
偏侧性，即将大脑功能划分为两个独立半球的现象，在动物分类中广泛存在。具有偏侧性的个体表现出认知优势，但偏侧性存在很大的差异，尤其是在性别之间。为什么会保持这种差异尚不清楚，因为很少有研究考虑过不同性别之间的偏侧性行为差异，以及它们在不同环境下的潜在选择压力。我们研究了个体在回避障碍物以观看不同行为情境代表的视觉刺激时，是否表现出偏侧性的方向、强度和一致性的性别差异：一个熟悉颜色的人工物体、一个异性同种动物和一个没有刺激控制的物体。虽然在偏侧性的方向或强度上没有明显的性别差异，但在性别之间，偏侧性的强度一致性存在差异。两性个体都一致地偏向一个方向，但雄性个体在不同情境下的偏侧性强度比雌性个体更具可预测性。这表明，在生态相关场景中偏侧性的可预测性代表了性别之间一个关键但以前未被探索的变异来源。
