Weird pupils let octopuses see their colorful gardens | Hacker News Reader

Weird pupils let octopuses see their colorful gardens

news.berkeley.edu

122 pointsronald_raygun31 comments

For a moment there, that headline had me thinking that school kids who happen to be weird have colorful gardens and are showing these gardens to octopuses.

Yea, best clickbait ever :)

I'm not going to click it, and just keep believing this.

[cephalopds] are colorblind – their eyes see only black and white – but their weirdly shaped pupils may allow them to detect color

Do PR people ever think about the awfulness of the drivel they write? I see the point the author is trying to make here but writing self-contradictory sentences is not the wright approach.

  Cephalopods, long thought to be color-blind, may in fact be able to detect color....

  Although the retinas of cephalopods cannot detect different colors, new research suggests they may be able to detect color another way.

  ...etc.

Wow. This is cool. For anyone else who's interested, the full paper is at http://www.pnas.org/content/113/29/8206.full and supplemental information (including movies) at http://www.pnas.org/content/suppl/2016/07/01/1524578113.DCSu... .

The "S1" video is a classic, and every time I see it I do like it again and again.

The original is AFAIK by Roger Hanlon:

https://www.youtube.com/watch?v=aoCzZHcwKxI

http://www.mbl.edu/bell/current-faculty/hanlon/

Who has published a few more nice videos here:

http://www.mbl.edu/bell/current-faculty/hanlon/videos/

I hadn't seen these before. They're great. Thanks!

Took me a second. "why would students be showing a garden to an octopus?"

Oh, and I love your username op. My brother started a comic with that same title, never did finish it

> why would students be showing a garden to an octopus?

Well according to the title those students are weird... :-)

Went to many a punk show at the Nancy Raygun in Richmond, VA. Great little venue.

What a beautiful hack by nature. I wonder if you could create a lens with a similarly shaped pupil/iris and see the chromatic aberration in a black and white camera correctly focused on the output. Would make for a fun weekend project :)

The black and white film is still only going to record black and white images ... The "may be able to judge color" part of the theory requires "processing". You might however be able to digitize your black and white photo and "colorized" it.

It would be interesting to develop software that can colorize an image based on multiple images with different focus.

Maybe possible to use this technique on space probes to capture true colors in a single channel, saving on data transfer

This was brilliant to me at first blush. After thinking about it, though, wouldn't the image have to be a higher resolution to compensate for the blurring of the chromatic aberration? When you process out the blur to extract the color information, you'll have less resolution left over. I'm guessing that would offset the gains on using a single channel. Ultimately for "full color", at a specific resolution, you need a specific number of bits of information, regardless if it's encoded in three color channels, or a single channel.

Yea just throwing it out there. I think you're right it would most likely require more data

Kudos for the idea ... getting people thinking about the possible engineering applications is awesome!

It might still be good for other reasons, though. Like if the colour filters used in space probes degrade over time (I don't know, do they?) then it would allow more consistent colour recording. Also it might be usable on very small probes that primarily take black and white images but can capture colour (at expense of resolution) if required.

Actually, the opposite, this is the same principle as a hyperspectral sensor. These line scan sensors (kind of like the pupil photos in the article) create "data cubes" (i.e. an 2D image with a 3rd spectral dimension for every spatial pixel) which are huge compared to red, green, & blue images. The article actually talks about how computationally intensive it is to handle and how that made squid so smart.

Can't let a post on octopi go by without re-posting this amazing out-of-the-water predation:

https://www.youtube.com/watch?v=F5fZu-1bt6Y

Octopus does not originate from latin, but instead greek. So it would be octopodes[0], however, we all speak english, so octopuses is fine. Or, you know, use what you want because english isn't prescriptive...

[0]: https://en.oxforddictionaries.com/explore/what-are-the-plura...

I'm hip. In fact, saltshaker blended diffeomorphism, but rather crispness loves polarity muchness than tilings. Or not; I'm not really sure.

What a hoopy frood you are.

Fascinating tidbit for those who check the comments first:

> Intriguingly, using chromatic aberration to detect color is more computationally intensive than other types of color vision, such as our own, and likely requires a lot of brainpower, Stubbs said. This may explain, in part, why cephalopods are the most intelligent invertebrates on Earth.

Can someone tell me if I am understanding this right? If not, can you clarify?

This is how I understood it:

They don't have different cones cells for detecting color. Instead, their pupil is more like a slit, causing light to be diffracted, not unlike a prism. Because of the diffraction, different wavelengths of light fall on different areas of the retina. Their brain is mapped as such that they understand the location of the light as the color. Moving the eye around helps them refine this information.

How did they establish that octopuses are colorblind in the first place?

Wouldn't a behavioral test immediately reveal that they are not colorblind?

I'm curious about the scientific process here.

They looked at the retina, and at its lack of color cones.

I think something similar happened with dogs (no color cones), but then behavioral tests showed they have some limited color vision.

Are you sure about this? I seem to recall that dogs do have cones, just not many and not of as many varieties (that is, three) as we have.

I'm not a biologist nor vet, so not my area of expertise, but there are a lot of jokes about dogs being colorblind (tv series, movies, etc) and in the end it happens that they do have some limited color vision. Sorry I can't give any reference.

I wonder what their color range is; if I'm reading right, this isn't necessarily the same spectrum range that we are accustomed to.

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