Hsu Yuying, Huang Yu-Yun, Wu Ya-Ting
Department of Life Science, National Taiwan Normal University, 88, Section 4, Ting-Chou Rd., Taipei, 11677, Taiwan,
Anim Cogn. 2014 Mar;17(2):165-75. doi: 10.1007/s10071-013-0649-4. Epub 2013 Jun 13.
Many animals modify behavioural decisions based on information they have previously acquired. Contest behaviour is often affected by previous contest experiences: individuals behave more and less aggressively after a victory and defeat, respectively (winner/loser effect). Individuals in the field sometimes encounter multiple competitors in quick succession, but whether these experiences interact to influence each other's importance is unclear. We tested five hypotheses for experience interaction (no interaction, retroactive interference, proactive interaction, reinforcement and diminishing returns) using Kryptolebias marmoratus. Focal individuals were paired up with opponents having the same 1-month contest outcome (1 month before the experiment), as this difference in actual or perceived fighting ability has been shown to affect the fish's response to new experiences. We gave the focal individual of a pair a winning or losing experience on day 1. Then both fish of the pair received the same winning, losing or no-contest experience on day 2. Then we organised fights between the two. The effect of a day-1 losing experience did depend on the fish's actual or perceived fighting ability: one-month losers readily showed loser effects from the day-1 losing experience, irrespective of the day-2 experience (i.e. no interaction between day-1 and day-2 experiences). One-month winners, however, only showed loser effects from a day-1 losing experience when the day-2 experience was also a loss (i.e. reinforcement). Day-1 winning experiences did not interact with day-2 experiences in 1-month losers or winners. Therefore, multiple experiences sometimes reinforce each other, but how they combine to influence behaviour depends on an individual's actual or perceived fighting ability.
许多动物会根据它们之前获取的信息来改变行为决策。竞争行为常常会受到之前竞争经历的影响：个体在胜利和失败后，攻击性会分别增强或减弱（胜者/败者效应）。在自然环境中的个体有时会接连遇到多个竞争者，但这些经历是否会相互作用以影响彼此的重要性尚不清楚。我们使用食蚊鱼对经验相互作用的五个假设（无相互作用、追溯干扰、前瞻相互作用、强化和收益递减）进行了测试。将焦点个体与具有相同1个月竞争结果（实验前1个月）的对手配对，因为实际或感知到的战斗能力差异已被证明会影响鱼对新经历的反应。在第1天，我们让配对中的焦点个体获得一次胜利或失败的经历。然后在第2天，配对中的两条鱼都获得相同的胜利、失败或无竞争经历。之后我们安排它们之间进行争斗。第1天失败经历的影响确实取决于鱼的实际或感知到的战斗能力：无论第2天的经历如何（即第1天和第2天的经历之间无相互作用），1个月来的失败者很容易从第1天的失败经历中表现出败者效应。然而，1个月来的胜利者只有在第2天的经历也是失败时，才会从第1天的失败经历中表现出败者效应（即强化）。1个月来的失败者或胜利者中，第1天的胜利经历与第2天的经历之间没有相互作用。因此，多种经历有时会相互强化，但它们如何结合起来影响行为取决于个体的实际或感知到的战斗能力。
