how do they know what colors dogs can see there's this myth that won't go away that dogs only see in black and white but that's just not true there's a bunch

他們怎麼知道狗能看到什麼顏色？有一個迷思一直揮之不去，說狗只能看到黑白，但那根本不是真的。現在有一堆

of apps and filters now that claim to show dog color vision but where does our understanding of this K9 rainbow come from and do these filters really capture how dogs see the world

應用程式和濾鏡聲稱可以顯示狗的色覺，但我們對這個犬類彩虹的理解是從哪裡來的？這些濾鏡真的能捕捉狗如何看世界嗎？

before we get to dogs how do we know what colors humans can or can't see I'm sure you've seen these before right yeah do you have normal color vision I have I

在我們談到狗之前，我們怎麼知道人類能看到或不能看到什麼顏色？我相信你以前看過這些，對吧？是的。你有正常的色覺嗎？我有，我

think normal color vision I think that says 45 so what just happened there light from this image entered Cleo's eye where it hit cells in her retina called cones that in turn sent electrical

想是正常的色覺。我想那個顯示 45。那麼剛才發生了什麼？來自這張影象的光進入了 Cleo 的眼睛，撞擊到她視網膜上稱為視錐細胞的細胞，然後傳送電

signals to her brain which created her perception of color this rainbow is just how our brain translates different wavelengths of light from one small section of the electromagnetic spectrum

訊號到她的大腦，創造了她對顏色的感知。這道彩虹只是我們大腦翻譯電磁光譜中一小部分不同波長光線的方式

Cleo like most people has three types of cone cells each one sensitive to a different part of the spectrum relatively short wavelengths of light medium wavelengths and long their

Cleo 像大多數人一樣，有三種型別的視錐細胞，每一種對光譜的不同部分敏感——相對短的波長、中等波長和長波長。它們的

sensitivity Peaks at specific points but it drops off smoothly in both directions so when what we call orange light comes in and hits an S cone its wavelength lands outside this sensitivity curve but

敏感度在特定點達到峰值，但在兩個方向上平滑下降。所以當我們稱為橙色的光進來並撞擊 S 視錐時，它的波長落在這個敏感曲線之外，但

if it hits an M cone a signal is produced and with the El cone an even stronger signal these signals are combined and interpreted by the brain as orange when so-called green light comes

如果它撞擊 M 視錐，就會產生訊號，而 L 視錐則會產生更強的訊號。這些訊號被結合並被大腦解讀為橙色。當所謂的綠色光進來

in the cones send a different set of signals green green and so people with normal vision can make out the number 45 in this pattern but what if you were

時，視錐傳送一組不同的訊號——綠色、綠色。所以視力正常的人可以在這個圖案中辨認出數字 45。但如果你

missing this m col like about .5% of the population both orange and green light would stimulate the elone about the same amount and without the M cone the

缺少這個 M 視錐，就像大約 0.5% 的人口一樣？橙色和綠色光都會以大約相同的程度刺激 L 視錐，而沒有 M 視錐，這些

signals would be too similar the brain wouldn't be able to distinguish between them and the number 45 would disappear into the background for those who can't read numbers like todders there are

訊號會太相似，大腦無法區分它們，數字 45 會消失在背景中。對於那些不能讀數字的人，比如幼童，有

versions of this test that just have the subject trace a loopy line but how do you design a vision test for a dog if I were trying to do this with

這個測試的版本只是讓受試者描繪一條彎曲的線。但你怎麼為狗設計視力測試？如果我要和

Thor I would concoct a test that involves getting food at the end if an only if he can demonstrate that he can see two different colors that's pretty

Thor 做這個，我會設計一個測試，如果且僅當他能證明他能看到兩種不同的顏色，就能在最後得到食物。這挺

much what Jay Knights did back in the late 1980s I said we have to solve this question once and for all I went home at lunchtime and got my dog a toy poodle

像 Jay Neitz 在 1980 年代末做的事情。我說我們必須一勞永逸地解決這個問題。我中午回家，帶了我的狗，一隻玩具貴賓犬

appropriately named retina brought him into the laboratory 7 days a week for a year lab setup was a little chamber there were three discs illuminated from behind the dog was trained to Boop

恰如其分地命名為 Retina，一週七天帶牠到實驗室，持續一年。實驗室裝置是一個小房間，有三個從後面照亮的圓盤。狗被訓練用鼻子碰

whatever disc looked different with her nose if she chose right she heard a click and got a little treat if she chose wrong no treat and a buzzer sound once retina learned that Jay

看起來不同的那個圓盤。如果選對了，她會聽到一聲響並得到一個小零食。如果選錯了，沒有零食並且會有蜂鳴聲。一旦 Retina 學會了 Jay

wanted her to identify the different Circle it was time for the real experiments one of the first experiments that we did we had three different white

要她辨認不同的圓圈，就該進行真正的實驗了。我們做的第一個實驗之一是有三個不同的白

lights and then we added a little bit of the particular color at first we'd add a little bit and the dog can't see it but

光，然後我們加入一點點特定的顏色。一開始我們加一點點，狗看不到，但

add more and the dog can pick it out and if it takes a very small amount any particular wavelength that means that they must be very sensitive for each color they plotted out this

加更多，狗就能辨認出來。如果只需要非常少量的特定波長，這意味著他們對那個顏色一定非常敏感。對於每種顏色，他們繪製了這個

sensitivity and we just marched across the whole entire rainbow this sensitivity curve strongly suggests that dogs have just two cones centered here and here and at this low point in the

敏感度，我們就這樣走過整個彩虹。這條敏感曲線強烈暗示狗只有兩個視錐，分別集中在這裡和這裡。而在中間這個低點

middle something interesting happened retina couldn't tell the difference between this color and white light there's some wavelength in the middle part of the spectrum that's kind of where the two cones out overlap the

發生了一些有趣的事情——Retina 無法分辨這個顏色和白光的區別。在光譜中間部分有某個波長，那裡兩個視錐重疊

light equally stimulates the two cones when all three of our cones are equally stimulated humans see Shades of Gray and the same would be true for dogs with

光線同樣刺激兩個視錐。當我們所有三個視錐都被同樣刺激時，人類看到的是灰色調，同樣的道理對狗和

their two cones for them this is the point of that equal stimulation another set of experiments mimicked those color blindness tests we talked about before and as you'd expect from someone with

他們的兩個視錐也是如此。對他們來說，這是那個等量刺激的點。另一組實驗模仿了我們之前談到的色盲測試，正如你對只有

just two cones Rea struggled to tell the difference between oranges and greens Jay confirmed his results with two other dogs and published them in 1989 now my

兩個視錐的人所預期的，Retina 很難分辨橙色和綠色。Jay 用另外兩隻狗確認了他的結果，並在 1989 年發表。現在我的

dog is much more famous in the realm of science that I am follow-up studies gathered similar data and if you put that together with what we know about

狗在科學領域比我出名多了。後續研究收集了類似的資料，如果你把這些和我們對

human Vision you can start to paint a picture of the rainbow that dogs see blue on one end Fading Into gray in the middle and then yellow on the other end

人類視覺的瞭解結合起來，你可以開始描繪狗看到的彩虹——一端是藍色，中間漸變成灰色，然後另一端是黃色

it's probably not that different from what a human missing their M cone would see it makes me wonder how many times I have interacted with Thor in a way that

這可能和缺少 M 視錐的人看到的差不多。這讓我想知道有多少次我和 Thor 互動時

kind of expected him to be able to see the full spectrum of color can I just put a filter on an image and be like oh this is what dog

某種程度上期望他能看到完整的色譜。我能不能就在影象上加個濾鏡然後說，哦，這就是狗

aene or are there complications to that oh I think it's it's way more complicated than that but that's a good first pass is it anywhere near the subjective experience I think not I mean

看到的？還是這有複雜的地方？哦，我認為這比那複雜多了。但作為第一步這很好。這接近主觀體驗嗎？我認為不是，我是說

there's a lot more complications just in the retina to begin with in addition to cones mammals have Rod cells that help them pick up light and motion and dogs

光是視網膜就有更多複雜的地方。除了視錐，哺乳動物還有視桿細胞，幫助他們感知光線和運動，而狗

have way more of these kinds of cells than humans that makes them more sensitive to movement and helps them see in low light they also have a layer called the deum lucidum that reflects

有比人類多得多的這類細胞。這讓他們對運動更敏感，幫助他們在低光下看東西。他們還有一層叫做脈絡膜反光層，可以反射

light back through the retina that's what makes dogs eyes shine at night then there's a difference in the arrangement of cells in the retina we have lots of

光線穿過視網膜——這就是為什麼狗的眼睛在夜間會發光。然後視網膜上細胞的排列也有差異。我們有很多

cells across all of the back of the eyeball but a especially dense group of cells in the center which enables us to see the thing that's right in front of

細胞遍佈整個眼球後面，但在中心有一個特別密集的細胞群，這使我們能夠看到正

us but some breeds of dogs are different they have a density of cells that sort of extends oh I just f um they have a density of cells uh that I

前方的東西。但有些品種的狗不一樣，他們有一種細胞密度是延伸的，哦，我剛剛……嗯，他們有一種細胞密度，我

love and that horizontal band of cells might make it easier for them to take in visual information across a broader swath of the Horizon the position of their eyes often gives them a wider

喜歡的那種，那個水平帶狀的細胞可能讓他們更容易接收更廣闊地平線範圍的視覺資訊。他們眼睛的位置通常給他們更寬的

field of vision but less overlap which means weaker depth perception dogs are also mostly nearsighted distant things are fuzzier then additionally dog's visual experience of the world is going

視野，但重疊較少，這意味著深度感知較弱。狗也大多是近視的，遠處的東西更模糊。此外，狗對世界的視覺體驗

to be completely tied up in the OR Factory experience of the world and this is the aspect of dog Vision that I don't think we humans can ever fully understand

將會完全和嗅覺體驗綁在一起。而這是狗的視覺中我認為我們人類永遠無法完全理解的方面

so this is just an image of the olfactory ponal in the human on the left and the dog on the right these are called Podunk these are olfactory Podunk

所以這只是人類和狗的嗅球的影象，左邊是人類，右邊是狗。這些叫做 Peduncle，這些是嗅覺 Peduncle

yeah that's a great word wow the olfactory system in the human takes up approximately .3% of the brain dogs do have a a hugely larger olfactory system they are detecting things that we are

是的，這是個很棒的詞。哇。人類的嗅覺系統大約佔大腦的 0.3%。狗有一個大得多的嗅覺系統。他們在探測我們

completely unable to detect there's a bunch of studies that show dogs can smell cancer malaria covid-19 explosives diseased avocado trees whale poop on the ocean even the emotional state of their

完全無法探測到的東西。有一堆研究表明狗可以聞出癌症、瘧疾、新冠肺炎、炸藥、生病的酪梨樹、海洋上的鯨魚糞便，甚至主人的情緒狀態

owners you know I do sometimes think when I put perfume on what my dog is thinking because it must be quite overwhelming for them here's another way to look at the brain these are

你知道，我有時候在噴香水時會想我的狗在想什麼，因為對他們來說一定非常強烈。這是另一種看大腦的方式。這些是

tractograms made with a special MRI technique and these lines trace the paths of white matter the fibers that speed signals between different regions of the brain you can virtually dissect these tractograms highlighting different

用特殊 MRI 技術製作的神經纖維圖，這些線條追蹤白質的路徑，即在大腦不同區域之間傳遞訊號的纖維。你可以虛擬解剖這些神經纖維圖，突出顯示不同的

roots roots for example here are the paths extending from Human old factory podal to other regions but here is the dog brain whoa there's information freeways running from the nose to other parts of

路徑。例如，這裡是從人類嗅球延伸到其他區域的路徑。但這是狗的大腦——哇。有資訊高速公路從鼻子通往大腦的其他部分

the brain and these weren't found before just because no one really looked yeah pretty much can you guess what this is circling it's going here yeah what is

而且這些以前沒被發現只是因為沒人真正去看。是的，基本上是這樣。你能猜到這個圈起來的是什麼嗎？它通往這裡，是的。這裡

there do you know I have no idea what's here me it's a little counterintuitive because in both humans and dogs the place that we process vision is actually the back of our head this

是什麼，你知道嗎？我不知道這裡是什麼。這有點反直覺，因為在人類和狗身上，我們處理視覺的地方實際上在頭後面，這個

occipital lobe back here oh so what you're saying is dogs are processing uh smell like we are processing sight sort of well it's interesting because it's not unique to the dog that they might

枕葉在後面這裡。哦，所以你的意思是狗處理嗅覺就像我們處理視覺一樣？某種程度上。嗯，有趣的是，這並非狗獨有，他們可能

use a different sense to generate Vision I mean we know the bats are a classic examp they can navigate through their auditory Pathways it's very possible that dogs can identify structures in the

使用不同的感官來產生視覺。我是說我們知道蝙蝠是經典的例子，他們可以透過聽覺通路導航。狗很可能也能從氣味中辨識房間裡的

room from scent as well as from from Vision seeing and smelling are interwoven in an important way and that is something completely unlike what we have in our brain when I think about my

結構，就像從視覺一樣。看和聞以重要的方式交織在一起，這和我們大腦裡的完全不同。當我想到我

sense of the world my mental map of where I am in space where other things are like how those things relate to each other and move like all of that is

對世界的感知，我的心理地圖，我在空間中的位置，其他東西在哪裡，這些東西如何相互關聯和移動——所有這些都是

visual we literally use the word visualize like that's that's what I'm thinking um yeah but for a dog like now I'm imagining Thor's sense of the world

視覺的。我們字面上使用「視覺化」這個詞——那就是我在想的東西。嗯，是的。但對於狗來說，現在我在想像 Thor 對世界的感知

and his place in it is like a spatial awareness that depends on smell that's fascinating wow I don't even know I can't grock this fully yeah I I mean I

和他在其中的位置是一種依賴嗅覺的空間感知。這太迷人了。哇，我甚至不知道……我無法完全理解這個。是的，我，我是說我

think it's impossible to grock it's UNG rockable have you come across this term umelt no it's a term that comes from this German bi ologist whose name I can't remember right now but it's

認為這是不可能完全理解的。這是無法被理解的。你有遇過這個詞嗎——Umwelt？沒有。這是一個來自一位德國生物學家的術語，我現在想不起他的名字，但這是

something I couldn't pronounce even if I could remember itob Johan and umelt it refers to the different realities experienced by different organisms the set of things that are meaningful to

即使我能記得也無法發音的東西。雅各布·馮·尤克斯庫爾。而 Umwelt 指的是不同生物體驗的不同現實——對他們有意義的一組事物，

them some of which we can't even sense you come to see that we're just seeing like but one of many worlds which are existing in parallel and other animals

其中一些我們甚至無法感知。你會開始看到我們只是看到許多平行存在的世界中的一個，而其他動物

are seeing in another slice our rainbow might be more varied than that of a dog but their old factory world is so explosively col ful that it wouldn't

在看另一個切片。我們的彩虹可能比狗的更豐富，但他們的嗅覺世界如此爆炸性地色彩斑斕，他們一秒鐘都不會

occur to them for a second that there's something that's being missed this is it really does help me understand my little best friend better I feel I feel like I

想到有什麼被遺漏了。這真的幫助我更好地理解我的小好朋友。我覺得，我覺得我

I feel connected to his world and sort of an appreciation that his world is different and also beautiful I don't see Rowdy in his box today but you're also a cat guy can cats

和他的世界產生了連結，也對他的世界是不同的而且也很美麗產生了一種欣賞。我今天沒看到 Rowdy 在他的箱子裡，但你也是貓奴。貓能做

do the booping test I find it hard to believe that might be my my stereotypes about cats but have people investigated this and what do we know about cat color

碰鼻子測試嗎？我很難相信。這可能是我對貓的刻板印象，但有人研究過這個嗎？我們對貓的色覺瞭解多少？

vision well hey everybody it's Adam from The Future it's the next morning I've got Rowdy back with me um and I've been up all night reading cat studies

嗯，大家好，我是來自未來的 Adam。現在是第二天早上，Rowdy 又和我在一起了。嗯，我整晚都在讀貓的研究