Why Velcro 3D glasses onto cuttlefish? In Episode 69, Trevor Wardill from the Department of Ecology, Evolution and Behavior at the University of Minnesota discusses his research into the previously unknown ability of the cephalopod to see in stereo vision. His article, Cuttlefish use stereopsis to strike at prey,“ was published along with multiple co-authors on January 8, 2020 in the journal Science Advances.

Cuttlefish in 3D Glasses - Trevor Wardill
Cuttlefish in 3D Glasses - Trevor Wardill
Cuttlefish in 3D Glasses - Trevor Wardill Cuttlefish in 3D Glasses - Trevor Wardill
@rwatkins says:
Next time, in episode 70 of Parsing Science, we’ll be joined by Jeremy Gunawardena from the Department of Systems Biology at Harvard Medical School. He’ll discuss his research replicating an experiment originally conducted over a century ago, confirming that at least one single-cell organism – the trumpet-shaped Stentor roeselii – is capable of surprisingly complex decision-making behaviors.
@rwatkins says:
Trevor’s study appeared not once – not twice – but three separate times on CNN’s homepage … at the same time! This led Doug and I to surmise that what’s so compelling about the study isn’t that you can put 3D glasses on a cuttlefish to fool it into thinking that a video of a shrimp is real: it’s that you apparently have to, suggesting to us that there must be a lot going on in their minds. So we closed out our conversation by asking Trevor his thoughts on the matter.
@rwatkins says:
Trevor and his team’s study tested three different manipulations. In the first, the pixels comprising the left and right portions of the shrimp were correlated in such a way that both humans and cuttlefish are able to properly determine the image’s depth. In the second condition, the pixels were anti-correlated such that humans wouldn’t properly detect their depth, but – like praying mantis – they found that the cuttlefish could. Lastly, when the pixels were uncorrelated … a condition in which praying mantis are still able to detect depth, both humans and cuttlefish can not, as Trevor explains next.
@rwatkins says:
Trevor’s article reports three surprising findings regarding cuttlefish vision: first, they see in stereo; second, they strike at shrimp more quickly when they’re able to perceive depth; and third, they can extract 3D cues even when the information received by each eye isn’t correlated in the way that’s required by humans. We asked Trevor what these findings suggest about cuttlefish vision, and how that’s different from what we’ve previously known about how it works.
@rwatkins says:
Since studying the eye movements of cuttlefish – whether donned in 3D glasses or not – has to be a non-trivial task, Ryan and I were curious about the experimental set-up that allowed Trevor and his team to capture detailed information about their vision.
@rwatkins says:
While it’s more common today for 3D movies to be viewed with grayish polarized glasses, the earliest system used one red and one blue lens to form a stereoscopic 3D image. As these were the sort of lenses that Trevor and his team used as well, we asked him to remind us how 3D glasses create the illusion of depth, as well as how red/blue lenses could work with cuttlefish, since they lack color vision. We’ll hear what he had to say after this short break.
@rwatkins says:
With these “preliminary” matters out of the way, Ryan and I were eager to learn: just how do you go about putting 3D glasses on a cuttlefish anyhow?
@rwatkins says:
Unlike us, the eyes of cuttlefish are on the opposite sides of their heads. So they obtain 3D vision through a process called “vergence,” in which their eyes rotate towards each other when focusing on closer objects, and away from each other when looking at objects that are farther away. We asked Trevor to explain how this process operates.
@rwatkins says:
Trevor’s lab investigates the neural processing of visual information by invertebrates, the knowledge of which is particularly scarce. Much of their research focuses on visual circuitry of the fruit fly, as well as in other species of flies. But he and his team are also interested in the visual system of cuttlefish, which – like squid and octopuses – are cephalopods. So Ryan and I were curious what interested him in studying these animals.
@rwatkins says:
To start out our conversation, we asked Trevor to describe what cuttlefish are like, as well as why they’re of such interest to researchers.
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Websites and other resources

      • Sendup of Trevor’s experiment on The Late Show with Stephen Colbert:

      • Wired video on Jenny Read‘s researcher into stereopsis among praying mantis:

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    Hosts / Producers

    Ryan Watkins & Doug Leigh

    How to Cite

    Watkins, R., Leigh, D., & Wardill, T.. (2020). Parsing Science – Cuttlefish in 3D Glasses. figshare. https://doi.org/10.6084/m9.figshare.11936289


    What’s The Angle? by Shane Ivers


    Trevor Wardill: As you might guess, some cuttlefish – when you put glasses on their head – don’t want to wear them.

    Ryan Watkins: This is Parsing Science: the unpublished stories behind the world’s most compelling science, as told by the researcher themselves. I’m Ryan Watkins.

    Doug Leigh: And I’m Doug Leigh. Today, in episode 69 of Parsing Science, we’re joined by Trevor Wardill from the Department of Ecology, Evolution and Behavior at the University of Minnesota. He’ll talk with us about his research into the previously unknown ability of cuttlefish to see in stereo vision: a trait which he identified by having them wear 3D glasses. Here’s Trevor Wardill.

    Wardill: Hello, my name is Trevor Wardill. I’m an assistant professor at the University of Minnesota in the department of Ecology, Evolution and Behavior. And I’ve had a fairly diverse pathway, you might say, to get to this point. As you might have guessed from my voice, I’m Australian. So, I grew up in Brisbane in Queensland and I did all my sort of major studies there. So, my Bachelor of Science. I did a year of honors research, so just like a small thesis. And then I did my PhD in Population Genetics of insects and plants – and that was a biologic control inspired thesis – to investigate sort of genetic diversity in insects that are used to control plants. And during my PhD I met my wife; well, wife-to-be. So that sort of inspired a lot of moving all over the planet. I ended up doing a lot of postdocs. Ended up culminating in me getting, well, quite a prestigious fellowship at the University of Cambridge in England. And that’s called a David Phillips Fellowship. And it means that you get to start your own lab and go after research questions that are fairly ambitious, because they fund you very well to do that. It is sort of a launching platform to do science and I guess ultimately get me the position that I have now at the University of Minnesota.

    Watkins: To start out our conversation, we asked Trevor to describe what cuttlefish are like, as well as why they’re of such interest to researchers.

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