0000000000186315

AUTHOR

Giordano Ramos-traslosheros

Luminance Information Is Required for the Accurate Estimation of Contrast in Rapidly Changing Visual Contexts.

Summary Visual perception scales with changes in the visual stimulus, or contrast, irrespective of background illumination. However, visual perception is challenged when adaptation is not fast enough to deal with sudden declines in overall illumination, for example, when gaze follows a moving object from bright sunlight into a shaded area. Here, we show that the visual system of the fly employs a solution by propagating a corrective luminance-sensitive signal. We use in vivo 2-photon imaging and behavioral analyses to demonstrate that distinct OFF-pathway inputs encode contrast and luminance. Predictions of contrast-sensitive neuronal responses show that contrast information alone cannot ex…

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An optimal population code for global motion estimation in local direction-selective cells

AbstractNervous systems allocate computational resources to match stimulus statistics. However, the physical information that needs to be processed depends on the animal’s own behavior. For example, visual motion patterns induced by self-motion provide essential information for navigation. How behavioral constraints affect neural processing is not known. Here we show that, at the population level, local direction-selective T4/T5 neurons in Drosophila represent optic flow fields generated by self-motion, reminiscent to a population code in retinal ganglion cells in vertebrates. Whereas in vertebrates four different cell types encode different optic flow fields, the four uniformly tuned T4/T5…

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The physiological basis for contrast opponency in motion computation in Drosophila

This dataset contains traces (dF/F0) from in vivo two-photon calcium imaging from Tm1, tm2, Tm4, Tm9, CT1, and T5 neurons from responses to ONOFF fullfield flashes, ON and OFF bars, and moving sinewaves.

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