shrimp colour drama

Really wish talking about what shrimp see didn't remind me that in farming them females have one eye removed to promote breeding

https://en.wikipedia.org/wiki/Eyestalk_ablation

Technically, all the colors are fake. They're just the halucinations of a brain trying to understand the input from sensory organs.

That doesn't make them fake, in the same way that x can mean 2. You are merely representing a given value (in this case light within a certain electromagnetic spectrum) in a useful way.
- But is my red the same as your red? Hmmm?
- I hadn't thought about it that way.

Imagine how OP their colour perception would be if they did have that mental processing power

I hate that it invalidates this episode of radiolab, which is, without a doubt, a masterpiece of podcasting:

https://youtu.be/jibvu9BHV_k?t=795

i saved the video at the 13 minute mark where they do the audio representation of the vivid colors. still worth a watch/listen

But compared with human eyesight, they could still see more 'colors' - As we see (almost) the same white in incandescent bulbs as LEDs and fluorescents, they might actually see the component colors and their intensities.

Not unlike how we may hear a combination tone when multiple other tones are played, and hear the difference (or sum) of them.

How would you suggest they do that. White light near equally activates our 3 cones because all spectrums of light are in it.

White light near equally activates all 12 shrimp cones because all spectrums of light are in it.

Which spectrum of color is left out of white light that wouldn't light up a cone associated with it?
- 6500k vs 5000k is noticeable for humans

How did they test if they could see color? Did they make little shrimp dioramas or something?

They asked them politely
They give them a miniature color blind print that has those numbers in them that are hidden if you are color blind.

My whole world is crumbling

The shrimp are holier than we are because they cannot see the devil's color (it's pink 🩷)

You mean light red?
- ITT: people saying pink (light red) when they mean magenta
- That is clearly embarrassed white

The way mantis shrimp see is nonetheless super cool and interesting. They likely have no conception of 2D color at all, and can only sense the 12 different colors in general. Furthermore, only the midband of their eyes see color, when the eyes are moving and scanning for prey, they don't see color at all, which probably helps offload mental load for their small brains. Once they do see something, they then stop moving their eyes to determine the color of what they're looking at.

Also, mantis shrimp have 6 more photoreceptors in addition to the 12 colored ones, to detect polarized light. They likely see them the same way that they see color, so they probably don't consider them anything different than wavelength which is what we interpret as color.

Ed Yong's An Immense World has a section on this and I'd highly recommend it. The ways animals sense and perceive the world are often so different for ours and it's so fascinating.

For anyone wondering why they would need to see polarized light: I actually looked into this a few months ago!

Other animals that are trying to blend in with the environment often use countershading appear less conspicuous. The problem with this is that this method can't replicate the polarization of the light behind them, making them stand out if you can see that sort of thing. ((Sunlight in the ocean is always polarized based on the direction of the sun (look up fresnel equations for s and p polarized light))). Even transparent creatures will interrupt the polarization in some way, so this is a very useful skill to have.
- More specifically, polarization changes with the angle of reflection of the surface towards the detector / eye / camera, so every bump in the surface gets a color gradient different from the surroundings when seen by a polarization sensitive eye
"Spiders can detect danger coming their way with an early-warning system called eyes."

Really fantastic book. I did have some notes though. Firstly, if honeybees have such low dpi vision, how can they see each other dance? I assume it's because they're experiencing the dance some other way, but how? (Also it's hella dark in there, isn't it?)

He says many times that humanity's umwelt is dominated by sight, but I very much disagree. To lose my hearing or sense of touch would make me feel quite blind, as I use them to perceive things outside my cone of vision constantly. Being in deep water is unnerving for this reason, because I can't "see" what's around me, and I have this whole new area below that I can't hear either. So I have to wonder whether other people feel the way he does or whether my usage is more unique.

He really blew my mind when describing exafference and reafference because these things are reliant on a sense of self in the first place, which means that even the worm in his example must have some form of ego.
- how can they see each other dance? I assume it’s because they’re experiencing the dance some other way, but how? (Also it’s hella dark in there, isn’t it?)
  
  By touch. This 50s video shows it well.
- You show that you are dominated by sight even as you say you aren't.
  
  Losing your hearing or touch would remove peripheral senses, yes, and certainly that would be unnerving, but think how much worse it would be to lose sight. Hearing wasn't even a factor for you beyond your peripheral, because what you can see is so much clearer, so much more comprehensive, than what you can hear, that hearing is negligible where you have sight.
  
  Hearing is a backup sense. Something you lean on when you don't have sight, but its fidelity is poor enough in people that we rely nearly wholly on sight, when we can.
  
  Losing that cone of vision impacts us far more than our hearing, although of course losing either is massively detrimental.

Reminds me a little of CD digital audio. The original Red Book audio standard hasn't really been improved upon because it's uncompressed audio which covers basically all of the range of human hearing within the capabilities of any speaker we could build. It's uncompressed because in the early 80's when the tech hit the market, it was completely unfeasible to include the CPU and RAM needed to decompress audio in real time.

Shrimp has more color receptors because he doesn't have enough neurons to run trichromacy, so he sees in EGA.

Shrimp has more color receptors because he doesn’t have enough neurons to run trichromacy, so he sees in EGA.

love this. nice job :)
- I remember experiencing the EGA to VGA graphics evolution when I was growing up. I remember thinking the VGA almost seemed too real.
  
  In my mind, this was a game that felt like it was pretend:
  
  But this felt entirely too real:
Oh man.

12 year old me waiting for hours to rip mp3s from cds always wondered about this.

Like why isn't it already compressed?

The answer is that storage was available but processing wasn't. Amaze.
- Mp3 is already compressed, as is the MP2 CDs use.
  
  If it wasn't conpressed, you'd be looking at CDs per track, instead of tracks per CD.
Is moral of your story that adults having frequency detection limited to 16khz, with older adults lower, might still be able to detect music well enough?

I think this speaks to a significant misunderstanding that most people hold of the way vision actually works.

Most people imagine that vision is a relatively simple process by which our eyes detect and transmit to us the nature of the world. Not so.

Eyes are complex and interesting organs in their own right but fundamentally what they do is relatively simple. They are able to detect and report to the brain certain qualities of the light that hits them. Primarily these are: intensity, direction, and proximity to three points on the frequency spectrum (what we perceive as red, green, and blue). But this data alone is not vision. Vision is a conscious experience our brains create by interpreting and processing this data into the visual field before us—basically, a full scale 3D model of the world in front of us, including the blended information on reflection and emission that color entails.

Quite amazing! Most of this takes place in the human brain, and not the eyes. From this perspective, it is not terribly surprising that an organism with more complex eyes but a much simpler brain might have worse vision than we do.

Ha! I read the following Science new article just today about how Purple Only Exists In Our Brains. It's written for a younger audience (I think), but it lays out how our sight works, and how our brains trick us into seeing purple (a red-blue colour, as opposed to violet).

Poor shrimpos, no purple for them, I bet.
It’s amazing and crazy to think, too, that the “theater” our brains create is an equilibrium point of laziness (to save energy) and usefulness (to help survival). So, surely, there are things we are just unable to see. But also, probably, there are different things that get mapped to the same things in the “theater.” I’m just speculating though but it makes sense.
We don’t really detect direction of light exactly. Instead we detect the location in the eye where the light landed, and have lenses to focus the light onto our retina. That relationship does imply some of the directionality of the light, by ignoring light that goes in certain directions and relating the direction of light that does get detected to the location it ends up.
- By the same logic, we don't detect light, just the change in shape of certain proteins. The sky isn't blue, it's a subset of sunlight. We don't really touch things, we transmit forces with tiny magnets. Computers don't really do math, they just arrange states in certain ways.
- *we detect the direction of light by the location in the eye....ect.
  
  There fixed it for you.
- Yeah I was trying to avoid those details. I think it’s fair to summarize that as a system that detects the direction light is coming from.

Disappointed. But didn't the have receptors for differently polarized light? What about that?

Polarization filters on retinal photoreceptor won't make light wavelength (color) be perceived different, it just changes the conditions in which it's detected. If those polarized cells would cover unique colors compared to the rest, it would kinda resemble the highlight effect in Mirror's Edge, where something with a different angle than the surroundings stand out (sudden color gradient)
Color me appointed, at least we're not missing out on fresh new colors!

Horrible news

Ruined my day tbh

Isn't it amazing how birds reverse engineered airplanes?

Did a shit job of it too, got the wings all flapping around like a bunch of idiots.

"In short, I am superior to any other species, race, or creed. And especially femoids, fuck them."

PussSlayer666, CoD Clan Leader.

Green and red do not come back yellow, it makes brown…or is there some other process they’re describing?

There is two types of color blending, tint and light.

Tint is what is usually taught, primaries are red, blue,yellow and we make the rest with them.

With light however, the primaries are Red, Blue and Green. Most image editing software use light blending, so you can zoom on a pixel and use a color picker to get its RGB value. And to make yellow with light blending, you combine red and green

Extra fun fact! Tint primaries are actually Magenta, Yellow, and Cyan.

Red + Blue = Magenta Red + Green = Yellow Green + Blue = Cyan

Magenta + Yellow = Red Magenta + Cyan = Blue Cyan + Yellow = Green
My apologies if I missed the /s but eyesight works in additive colors, not subtractive

Shrimply*

This is really cool, but it's also over a decade old info. I remember growing up in awe of Mantis shrimp and then, as with all wonder, this was removed from my life in adulthood. :)