Honeybees (Apis mellifera) learn color discriminations via differential conditioning independent of long wavelength (green) photoreceptor modulation

BACKGROUND: Recent studies on colour discrimination suggest that experience is an important factor in how a visual system processes spectral signals. In insects it has been shown that differential conditioning is important for processing fine colour discriminations. However, the visual system of many insects, including the honeybee, has a complex set of neural pathways, in which input from the long wavelength sensitive (‘green’) photoreceptor may be processed either as an independent achromatic signal or as part of a trichromatic opponent-colour system. Thus, a potential confound of colour learning in insects is the possibility that modulation of the ‘green’ photoreceptor could underlie observations. METHODOLOGY/PRINCIPAL FINDINGS: We tested honeybee vision using light emitting diodes centered on 414 and 424 nm wavelengths, which limit activation to the short-wavelength-sensitive (‘UV’) and medium-wavelength-sensitive (‘blue’) photoreceptors. The absolute irradiance spectra of stimuli w...

研究背景：近期有关色彩辨别的研究表明，经验是影响视觉系统处理光谱信号方式的重要因素。已有研究证实，差异化条件化训练对昆虫的精细色彩辨别加工具有关键作用。然而，包括蜜蜂在内的多数昆虫的视觉系统拥有复杂的神经通路：长波长敏感光感受器（long wavelength sensitive photoreceptor，俗称"绿色"）的输入信号，既可以作为独立的消色差信号进行加工，也可作为三色对立色系统的组成部分进行处理。因此，昆虫色彩学习研究中存在一项潜在混淆变量："绿色"光感受器的信号调制可能是各类观测结果的内在成因。
研究方法/主要发现：本研究采用中心波长分别为414nm与424nm的发光二极管（Light Emitting Diode, LED）对蜜蜂视觉功能进行测试，此类光源仅能激活短波长敏感光感受器（short-wavelength-sensitive photoreceptor，俗称"紫外"）与中波长敏感光感受器（medium-wavelength-sensitive photoreceptor，俗称"蓝色"）。受试刺激的绝对辐照度光谱为w……