Dataset of cone opponent mechanisms and spectral tuning in non-primate vertebrates

Abstract

Cone and spectral opponency are fundamental to colour processing in many species and are well studied in primates. The data required to make interspecific comparisons of the neural mechanisms associated with colour processing is spread across a broad body of literature reaching back to the 1950's across four retinal cell types and multiple brain regions. We aimed to produce a comprehensive dataset of all known cone opponent cells in non-primate vertebrates in image forming visual pathways. We completed a systematic literature search of two databases, Web of Science and Scopus, following PRISMA guidelines. From the data collected, we produced three datasets. One dataset contains cone opponency data that indicates which photoreceptors drive cell light responses. The second dataset contains spectral opponency data that represents the cell electrical responses to different wavelengths of light. Additionally, we developed a third database of photoreceptor data for the species for which cone or spectral opponency was reported to supplement the first two. These datasets will provide a synthesis of the data in the field of colour processing, can be used for interspecific and intraspecific meta-analyses, and can provide a starting point for understanding neural mechanisms behind wavelength comparisons in non-primate vertebrates.

Keywords: Colour vision; Comparative physiology; Photoreceptor; Retinal mechanisms.

Fig. 1

The proportion of species found to express cone opponency in different cell types and the major vertebrate classes to which those species belong. Of the 16 species reported for horizontal cells, 11 species were fish. Of the 13 species reported for Retinal Ganglion Cells, 7 were mammals.

Fig. 2

The proportion of species found to express spectral opponency across cell types and the major vertebrate classes to which those species belong. Of the 46 species reported for horizontal cells, 41 species were fish.

Fig. 3

Reproducible Literature Search Flow Chart: Our reproducible literature search was conducted in three phases. The first phase, aimed at identifying and including studies about cone opponency in non-primate vertebrates, uncovered cone and spectrally opponent studies. The first search was insufficient for identifying every study on cone opponency in non-primate vertebrates. To expand our dataset, we used citation chasing in the second phase. This phase identified many more cone opponent studies. Our last phase was targeted at identifying spectrally opponent studies which may or may not have information about cone opponency.