Individual-Level and Population-Level Lateralization: Two Sides of the Same Coin
Individual-Level and Population-Level Lateralization: Two Sides of the Same Coin
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DOI：
10.3390/sym10120739
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发表时间：
2018-12-01
期刊：
影响因子：
2.7
通讯作者：
Vallortigara, Giorgio
中科院分区：
文献类型：
--
作者：
Frasnelli, Elisa;Vallortigara, Giorgio
侧化，即左右脑所扮演的不同功能角色，主要以两种方式表达：(1)在单个个体中，而不考虑群体的共同方向（偏见）（即个体水平的侧化）；或者(2)在单个个体中，并且大多数在同一个方向上，因此种群是有偏见的（又称种群水平侧化）。事实上，偏侧化经常发生在种群水平上，60-90%的个体表现出相同的方向（右或左）偏见，这取决于物种和任务。通常认为侧化可以提高大脑的效率。然而，这可以解释个体水平的侧化，但不能解释群体水平的侧化，因为个体的大脑效率与其他个体的不对称方向无关。从理论的角度来看，对种群水平侧化的一种可能解释是，它可能反映了一种进化稳定策略（ESS），当个体不对称的生物在特定的选择压力下协调它们与其他不对称生物的行为时，这种策略可以发展。这一预测有时会被误解，因为它等同于种群水平的偏侧化只存在于社会性物种的观点。然而，在所谓的“独居”昆虫的攻击性和交配表现中，已经观察到种群水平的不对称，这表明特定的个体间互动而不是“社会性”本身的参与可能促进种群水平的偏侧化。在这里，我们澄清了个体间相互作用的本质可以在个体或种群水平上产生进化稳定的侧化策略，这取决于生态环境，表明个体水平和种群水平的侧化应被视为同一连续体的两个方面。
Lateralization, i.e., the different functional roles played by the left and right sides of the brain, is expressed in two main ways: (1) in single individuals, regardless of a common direction (bias) in the population (aka individual-level lateralization); or (2) in single individuals and in the same direction in most of them, so that the population is biased (aka population-level lateralization). Indeed, lateralization often occurs at the population-level, with 60-90% of individuals showing the same direction (right or left) of bias, depending on species and tasks. It is usually maintained that lateralization can increase the brain's efficiency. However, this may explain individual-level lateralization, but not population-level lateralization, for individual brain efficiency is unrelated to the direction of the asymmetry in other individuals. From a theoretical point of view, a possible explanation for population-level lateralization is that it may reflect an evolutionarily stable strategy (ESS) that can develop when individually asymmetrical organisms are under specific selective pressures to coordinate their behavior with that of other asymmetrical organisms. This prediction has been sometimes misunderstood as it is equated with the idea that population-level lateralization should only be present in social species. However, population-level asymmetries have been observed in aggressive and mating displays in so-called "solitary" insects, suggesting that engagement in specific inter-individual interactions rather than "sociality" per se may promote population-level lateralization. Here, we clarify that the nature of inter-individuals interaction can generate evolutionarily stable strategies of lateralization at the individual- or population-level, depending on ecological contexts, showing that individual-level and population-level lateralization should be considered as two aspects of the same continuum.