Transfer from continuous to discrete quantities in honeybees

Honeybees can estimate quantities having different dimensions: continuous and uncountable such as the relative size of visual objects in an array, or discrete and countable such as the number of objects of the array. Honeybees can transfer quantity discrimination (i.e., choosing the larger/smaller stimulus) from number to size. Here we investigated whether honeybees could also generalize from the size (continuous) to the number (discrete) dimension. We trained free-flying foragers to discriminate between large and small size elements. At test, bees were presented with a comparison between larger and smaller numerosities controlled for different continuous variables co-varying with numerosity such as total area, total perimeter, convex hull, and element size. Results showed that bees generalized from the size to the numerical dimension of the stimuli. This cross-dimensional transfer supports the idea of a universal mechanism for the encoding of abstract magnitudes in invertebrate species comparable to that of vertebrate species.蜜蜂能够估算具有不同维度的数量：一类是连续不可数的维度，例如阵列中视觉物体的相对尺寸；另一类是离散可数的维度，例如阵列中的物体总数。蜜蜂可将数量辨别能力（即选择更大或更小的刺激物(stimulus)）从数量维度迁移至尺寸维度。本研究旨在探究蜜蜂是否也能实现从尺寸(连续)维度到数量(离散)维度的泛化。我们训练自由飞行的觅食工蜂区分尺寸大小不同的元素。在测试阶段，我们向蜜蜂呈现数量(numerosity)存在差异的对比组，并控制了与数量共变的各类连续变量，包括总面积、总周长、凸包(convex hull)以及单个元素的尺寸。实验结果显示，蜜蜂能够将对刺激物尺寸维度的辨别能力泛化至数量维度。这一跨维度迁移现象支持了如下观点：无脊椎动物与脊椎动物一样，拥有用于编码抽象量级的通用机制。