selected works

The perception of color involves a transformation from the spectral properties of visual stimuli to derived perceptual quantities such as brightness, saturation and hue. Although hue-selective neurons have been reported in primates, they have not been identified in other species. Here we show that neurons in the Drosophila optic lobe have hue-selective properties, with narrow tuning for both spectral and non-spectral colors. We construct a connectomics-constrained circuit model that accounts for this hue selectivity. Our model, combined with genetic manipulations, shows that recurrent connections in the circuit are critical for the tuning properties of Drosophila hue-selective neurons.

Understanding colour vision requires carefully designed stimuli. However, colour space geometry and the097 097 097relationship between stimuli and photoreceptor activations differ across species. We present a framework that exploits colour space geometry to design stimuli for any animal, based on its photoreceptor spectral sensitivities. We demonstrate the utility of this approach across species with different numbers of photoreceptor types.

Color vision begins with photoreceptors that have distinct spectral sensitivities. How photoreceptor signals are combined and transformed to extract chromatic information is poorly understood. We investigate chromatic encoding in Drosophila photoreceptors using a combination of electrophysiology, genetics, and modeling. We find that horizontal-cell-mediated feedback from downstream neurons shapes the chromatic properties of photoreceptor outputs, creating color opponency at the first stage of visual processing.