How animals perceive the world
(Vasas et al. 2024/PLOS Biology)
Have you ever wondered how the world looks through the eyes of a bee, a bird, or even a reindeer? Or maybe you saw your dog engrossed over a bush, having spotted something that only his canine eyes can perceive vividly enough to capture his attention. Thanks to a new camera system and software developed by scientists specialising in colour vision, we can now take a step closer to experiencing this fascinating phenomenon ourselves.
While we’ve learned to combine and weaponise colours in a myriad of ways to create fascinating outcomes, the fact remains that our human eyes are still severely limited in the spectrum of light they can perceive. More specifically, we miss out on the ultraviolet range that many animals, like bees and birds, can see with ease.
But that doesn’t mean that we’re objectively “underdeveloped” in that ocular race, either. Humans have receptors for red light that many animals, including mice and dogs, lack. And even if we compare ourselves with species who only perceive colours within light’s visible spectrum, the violet to red section of electromagnetic radiation, the “blueness” of the sky or the “greenness” of a leaf are luxuries only specific to our sensory system.
Now, with this innovative camera system, we can capture video footage in “animal-view” colours. This means we can visualise how the world might appear to different species, taking into account their unique range of light sensitivity and colour perception.
However, the fact that our eyes aren’t equipped to look for colours beyond the visible spectrum means we have to make certain approximations to actually observe the ultraviolet sections of light — what scientists call “false colour imaging”.
This technique involves shifting an animal’s perceivable colours into the human visible range, such as representing ultraviolet as blue and blue as green — slight shifts in the actual colours, but more representational of the overarching way animals might perceive them. But capturing movement with this method was impossible, as it required taking multiple photos with different filters, which wouldn’t work with a moving scene.
The key breakthrough came with the use of a beamsplitter, a specialised optical device that reflects ultraviolet light while allowing visible light to pass through. This enabled the scientists to simultaneously record both ultraviolet and visible light in a single video stream, using two commonly available cameras housed in a 3D-printed casing.
By overlaying and synchronising the recordings from both cameras, the researchers could calculate the amount of light each camera’s sensor received. This data then served as the basis for estimating how much light would reach the eyes of an animal observing the scene from the camera’s vantage point. A computer would then use this information to colour-transpose things into animal-view that we can perceive.
While we may never fully comprehend how animals experience the world, this new technology allows us to see it through their eyes to a remarkable degree. Imagine watching a bird flitting through a forest, its vision ablaze with ultraviolet hues invisible to us. Or observing a bee navigating a field of flowers, each bloom glowing with a unique spectrum of colours beyond our human grasp.
Now, here’s the fun part for those excited about this development: the team has made the resources ready to make the camera yourself, in case you want to further research on the field, or simply want your own glimpse of how your pet comprehends your house. Access the necessary codes here and the how-to on making the camera system here.
The findings of this research have been published in PLOS Biology and can be accessed here.
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