Departamento de Biología, Grupo de Investigaciones CANNON, Facultad de Ciencias Naturales, Universidad del Rosario, Bogotá, Colombia
Department of Biology, University of Nevada, Reno, NV 89557, USA.
J Exp Biol. 2020 May 18;223(Pt 10):jeb220103. doi: 10.1242/jeb.220103.
Similar to animal communication displays, flowers emit complex signals that attract pollinators. Signal complexity could lead to higher cognitive load for pollinators, impairing performance, or might benefit them by facilitating learning, memory and decision making. Here, we evaluated learning and memory in foragers of the bumble bee trained to simple (unimodal) versus complex (bimodal) signals under restrained conditions. Use of a proboscis extension response protocol enabled us to control the timing and duration of stimuli presented during absolute and differential learning tasks. Overall, we observed broad variation in performance under the two conditions, with bees trained to compound bimodal signals learning and remembering as well as, better than or more poorly than bees trained to unimodal signals. Interestingly, the outcome of training was affected by the specific colour-odour combination. Among unimodal stimuli, the performance with odour stimuli was higher than with colour stimuli, suggesting that olfactory signals played a more significant role in the compound bimodal condition. This was supported by the fact that after 24 h, most bimodal-treatment bees responded to odour but not visual stimuli. We did not observe differences in latency of response, suggesting that signal composition affected decision accuracy, not speed. We conclude that restrained bumble bee workers exhibit broad variation of responses to bimodal stimuli and that components of the bimodal signal may not be used equivalently. The analysis of bee performance under restrained conditions enables accurate control of the multimodal stimuli provided to individuals and to study the interaction of individual components within a compound.
与动物的通讯展示类似，花朵会发出吸引传粉者的复杂信号。信号的复杂性可能会给传粉者带来更高的认知负担，从而影响其表现，也可能通过促进学习、记忆和决策对它们有利。在这里，我们评估了经过训练的熊蜂觅食者在约束条件下对简单（单峰）和复杂（双峰）信号的学习和记忆能力。使用伸舌反应协议，我们能够控制在绝对和差异学习任务中呈现刺激的时间和持续时间。总的来说，我们在两种条件下观察到了广泛的表现变化，与接受单峰信号训练的蜜蜂相比，接受双峰复合信号训练的蜜蜂学习和记忆的能力以及表现更好或更差。有趣的是，训练的结果受到特定颜色-气味组合的影响。在单峰刺激中，气味刺激的表现优于颜色刺激，这表明嗅觉信号在双峰复合条件下发挥了更重要的作用。这一事实得到了支持，即 24 小时后，大多数双峰处理的蜜蜂对气味而不是视觉刺激有反应。我们没有观察到反应潜伏期的差异，这表明信号组成影响决策准确性，而不是速度。我们得出结论，受约束的熊蜂工人对双峰刺激表现出广泛的反应变化，并且双峰信号的组成部分可能不会被同等使用。在受约束条件下对蜜蜂表现的分析能够准确控制提供给个体的多峰刺激，并研究复合信号中个体成分的相互作用。
