Color vision

For many animals, color vision is important for survival, contributing to critical behaviors such as identifying food, detecting predators, and recognizing mates. How colors are processed in the central nervous system of di- and trichromatic vertebrate species (2-3 color cones) has been a topic of considerable research over the last decades. In contrast, the neuronal circuits supporting color vision in tetrachromatic vertebrates (4 color cones), such as birds, remain poorly understood. Through a combination of display engineering, large-scale Neuropixels recordings, and computational methods,

For many animals color vision is critical to make sense of their environment. Whether it's choosing the ripest fruit or identifying a potential mate, the perception of color is vital for the execution of these complex behaviors. How colors are processed in the central nervous system of di- and trichromatic vertebrate species has been topic of considerable research over the last decades. In contrast, the neuronal circuits supporting color vision in tetrachromatic vertebrates, such as birds, remain less well understood. Using newly developed in vivo 2-photon calcium imaging methodology and high-

…how they could encode changes in the color of the sky. I will summarize our recent connectomic investigation into the cone-opponent inputs to primate ipRGCs and the implications of this work on our understanding of cir

Color vision represents a vital aspect of perception that ultimately enables a wide variety of species to thrive in the natural world. For humans, a suite of color management tools, developed since the early 20th century and used in our everyday devices, allow for a straightforward investigation of human color vision. However, unified methods for constructing chromatic visual stimuli in a laboratory setting for other animals are lacking. This has limited the study of visual perception in animals, where the spatiotemporal and chromatic components of vision are often treated separately, and resu

I am working on color vision in Drosophila, identifying behaviors that involve color vision and understanding the neural circuits supporting them (Longden 2016). I have a long-term interest in understanding how neural computations operate reliably under changing circumstances, be they external changes in the sensory context, or internal changes of state such as hunger and locomotion. On internal state-modulation of sensory processing, I have shown how hunger alters visual motion processing in blowflies (Longden et al. 2014), and identified a role for octopamine in modulating motion vision duri

…Cichlid are a colorful group of fresh water fishes. They have undergone adaptive radiation throughout Africa and the new w

Among mammals, excellent color vision has evolved only in certain non-human primates. And yet, color is often assumed to be just a low-level stimulus feature with a modest role in encoding and recognizing objects. The rationale for this dogma is compelling: object recognition is excellent in grayscale images (consider black-and-white movies, where faces, places, objects, and story are readily apparent). In my talk I will discuss experiments in which we used color as a tool to uncover an organizational plan in inferior temporal cortex (parallel, multistage processing for places, faces, colors,

…the retina and can even contribute to color vision, but the extent of these influences has remained unclear. New results with more powerful methods of RNA expression profiling, specific cell labeling, and single-cell recording have provided greater clarity and are showing that rod and cone signals can mix at virtually every level of signal processing. These interactions influence the integration of retinal signals and make an important contribution to visual perception.

…nonvisual function important in color vision. This study demonstrates the evolutionary potential for increasing visual system functional diversity through opsin gene duplication