Color Vision: Trichromatic and Opponent Process Theories (Intro Psych Tutorial #46)

www.psychexamreview.com
In this video I discuss how color vision occurs and explain two important theories for understanding color vision, Young-Helmholtz Trichromatic Theory and Opponent Process Theory. Along the way I describe how some people are able to see ultraviolet (UV) light, a trick you can use to see infrared light, and two demonstrations of color afterimages.
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Need more explanation? Check out my full psychology guide: Master Introductory Psychology: amzn.to/2eTqm5s
Cone Type Sensitivity Graph: hyperphysics.phy-astr.gsu.edu/...
Electromagnetic Spectrum Illustration from NASA (public domain): en.wikipedia.org/wiki/Electro...
Flag color afterimage (public domain): open.lib.umn.edu/intropsyc/wp-...
Negative Color Afterimage from: www.opticalspy.com/opticals/ne...
Sorry for skipping the second H when writing Helmholtz!
Enable closed captioning or find a full transcript of this video here: www.psychexamreview.com/color-...

[@andrewkravmaga1833]

The opponent theory used to fairly hard to understand but the way you worded it has made it a lot easier. Thanks man.

[@PsychExamReview]

No problem, glad it was helpful!

[@danieljack9214]

Not sure if you guys gives a damn but if you guys are bored like me atm then you can stream pretty much all of the new series on InstaFlixxer. Been watching with my girlfriend recently :)

[@ashtonquincy3800]

@Daniel Jack yup, have been watching on InstaFlixxer for months myself =)

[@gregoryooi258]

"I know it's hard to do" cracked me up haha thank you for the explanation, I understand this material so much better :)

[@BlancaMoraMartinez]

Not funny, if you really need to see a sexualized image of a woman and use it as an object for your comprehension, it really shows your lack of intelligence.

[@Dionyboz]

@@BlancaMoraMartinez just shut up please

[@SuperPrissy11]

THIS EXPLANATION WAS AWESOME. THANK YOU!!! this will definitely help me for my test i have on monday!

[@gador5027]

Thank you so much for explaining! I didn't really have hopes of understanding colour theories anymore, but you've somehow managed to enlighten me. This was really helpful :)

[@PsychExamReview]

I'm glad to hear that, thanks for commenting!

[@PiyaChoudhari]

Exactly 💯 my thoughts he is the best teacher seriously !

[@Anthony-cn8ll]

What's interesting to me about the cone receptors is that L & M both peak near green. M being close to fully saturated computer green and L is more of chartreuse. You can test this with lasers (frequency doubled ND:YAG for the green and Helium Neon for the charteuse). I suspect that we adapted this so we see so many different variations of greenery in our environment, perhaps to identify various kinds of plants. Given that, it's kind of strange how we experience quite distinct qualities of yellow, orange, and red. It terms of photoreceptor firing, both L and M would taper off and after about 625 nm, the reds become less orangey and more rosey, closer to fuschia. This is when only the L receptor is firing. And the S receptor peaks at quite a violet color (Helium Cadmium if you want to make a laser). In terms of our perception, we have a large space of blue and cyan, then there's also smaller spaces of aquamarine and azure (the hue at 210 degrees, halfway between cyan and blue). I almost don't want to give azure its own name, because it just feels like another kind of blue to me. Maybe it's a lexical thing versus a qualia thing? I'm not sure to be honest. I know some cultures have the same word for blue and green for example. However, when I look at the sensitivities of the cones, all three cross in the aquamarine area and cyan area. Cyan being mostly just S and M, whereas azure seems to be low intensity on the S cone. I know it's all kind of silly talking in terms of pure wavelength, since we reality doesn't work this way (even lasers have fall off, if very steep), but I guess I just want to reconcile physics with my perceptive qualities of color. I want to understand why we have those qualities.

[@SunSunSunn]

Ah perfect for MCAT Psych/Soc section, thanks! I wish you made a video about Opponent process theory of emotion and the other stuff but this was really helpful.

[@PsychExamReview]

Glad to hear these videos are helpful. I left off opponent process theory of motivation from my videos on emotion and motivation because it's usually only briefly mentioned in intro classes, if at all. But if you have questions about it feel free to ask!

[@navaneeth5837]

I had been struggling with these topics a lot and I have psychology exams the next week. Thanks a lot

[@PsychExamReview]

You're welcome, best of luck next week!

[@jorgeandrade1545]

I was struggling to understand, the example you gave in <a href="#" class="seekto" data-time="565">9:25</a> made me understand everything, thank you so much.

[@ceciliasousa7102]

This is a lifesaver! You explain so well!

[@Pia-ho9dm]

Very informative and easy to follow explanations. After reading my notes I was confused as to why it said that the long-ranged cones could respond to wavelengths of light that appear yellow, green and red since I read that green was perceived when looking at an intermediate wavelength of light but now it is all clear.

[@ramulus694]

This topic is my exam question that is coming up, very informative video. Thank you! :)

[@PsychExamReview]

I hope it helps, good luck on your exam!

[@Symbu]

<a href="#" class="seekto" data-time="751">12:31</a> - this explains everything

[@WisallAbdulWakil]

This was a great video with a thorough explanation, thank you for uploading this!

[@PsychExamReview]

I'm glad you found it helpful, thanks for watching!

[@trig2mc6]

It helps a lot as a complement to my textbook reading. Thank you very much mate!

[@PsychExamReview]

You're welcome!

[@rhyannon8843]

Fascinating video and very well explained. I have a Psych question to answer which is compare and contrast the Trich and Opp Pro theories. I didn’t fully understand these theories until I watched your video. Thank you

[@PsychExamReview]

You're welcome!

[@ExistenceUniversity]

<a href="#" class="seekto" data-time="690">11:30</a> this is the best way I have heard this put. Very helpful

[@PsychExamReview]

Thanks, glad to hear it's helpful!

[@sydneykvrgnjas6429]

Thank you so much! I did not understand this concept at all from my textbook, but after one viewing I really got it!

[@PsychExamReview]

Great, glad to hear it helped you!

[@Sofia-jz9hj]

Dude your videos are saving my ass for the psych GRE! Its such a pain have to relearn stuff I haven't read about in three years lol. thanks so much!

[@PsychExamReview]

That's great, glad I can help!

[@damarismartinez2030]

Sooooooo helpful, I was struggling understanding the 2 theories, hopefully I do good on my exam

[@PsychExamReview]

Best of luck!

[@madisonmills8188]

I wish you were my teacher! ;) but for real you explain this really well!

[@catpeople11]

Explained opponent theory really well! Thank you!

[@PsychExamReview]

You're welcome!

[@ajay.6o9i]

Thanks for the remote-camera party trick! 😄 Awesome video🔥

[@PsychExamReview]

Glad you liked it!

[@karlaluna3458]

Thank you for such a great explanation! easy to follow and understand

[@PsychExamReview]

You're welcome!

[@drarnavjain]

Awesome Liked it a lot Get everything within 1st time Keep making such stuff Awesome

[@PsychExamReview]

Thanks, I really appreciate the compliments!

[@makocadey]

OMg! you awesome!! I could never learn this even after 3 different courses..i just couldnt and now it makes sense! Thanks!

[@PsychExamReview]

I'm really glad to hear that, I hope you find some of my other videos helpful too! Thanks for watching!

[@TheIceblue1]

Thank you for the explanation. It is so clear to me know!

[@PsychExamReview]

You're welcome!

[@julieannelovesbooks]

This made everything so much clearer!!!!

[@PsychExamReview]

Glad to hear that!

[@elisroom9506]

You helped me a lot thank you! Especially the bored explanation was helpful

[@PsychExamReview]

You're welcome, glad to hear that!

[@VikasDhavaria]

You are amazing. You have explained it extremely well. Thank you so much.

[@PsychExamReview]

You're welcome, thanks for commenting!

[@akriti1814]

Phenomenally explained 👏👏

[@PsychExamReview]

Thanks!

[@menasalman8534]

These videos are amazing. Thank you!!

[@PsychExamReview]

You're welcome!

[@vamika1657]

I am so much clear with these theories now thank you mannnn 🔥🔥🔥💯💯

[@PsychExamReview]

Thanks, glad to hear that!

[@laurawhite1173]

you're a legend, thanks mate

[@tejaswinich9421]

Woww , that's amazing !! Very Helpful for my exam, thanks ! 🙂

[@PsychExamReview]

Glad to hear it was helpful, thanks for commenting!

[@peiqicheng4378]

Your video really help me a lot !!!

[@PsychExamReview]

Glad to hear that!

[@laurenforster9264]

This helped so much! Thank you!!!

[@PsychExamReview]

You're welcome!

[@s93x]

great explanation, thank you so much!

[@PsychExamReview]

You're welcome!

[@sobahlemaseko9189]

Thank you!

[@0601013046]

i cudnt focus on X. my gaze automatically drifted a bit upwards. is there a theory to explain this phenomenon?

[@drarnavjain]

Ya Their is one That's called BULLSHIT theory of ur mind. 😂😂

[@DANGJOS]

It's called thinking with your second brain hahaha

[@gador5027]

Mycrosacchadic movement of your eyes. They kinda shake automatically anytime you stare at something, so that you'll continue to see (we need constant changes in illumination to be able to see. Completely static eyes cease to see in a few seconds), and so they sometimes have these bizarre effects. Eg look up the autokinetic effect, it's pretty rad

[@Lynk56]

When reading this my brain blurted "heterosexuality" and I started laughing, pls dont stone me

[@medhashreegoswami13]

You're the best teacher

[@PsychExamReview]

Thanks!

[@ethanjohn7638]

Hey man, thanks a lot for this!

[@PsychExamReview]

You're welcome!

[@kristimedina7558]

I would not pass in school if it wasn't for your videos. I wish textbooks were written the way YOU explain things!!!!

[@PsychExamReview]

I'm glad to hear that my videos are helping, thanks for commenting!

[@zain4132]

that you mean bored is hyperpolarization right? because when they hyper polarized you need much more stimulus (for short time period of time that you said 1 2 seconds)

[@PsychExamReview]

Great question, part of the physiological explanation for this fatigue is the bleaching of the photopigments which absorb light. This means that photoreceptors temporarily run out of their photopigments and this reduces their ability to signal properly. As for hyperpolarization, it's a bit counter-intuitive because photoreceptors become hyperpolarized when they absorb light, which decreases their release of glutamate, and depolarized in the dark, which releases more glutamate. Hope this helps!

[@shrawastilavanya7228]

thank you love you for this!

[@Alindber1]

Wait a second...is this an SNL skit about sexism in science/academia??! Hilarious! On point!

[@samiajjohn]

Thank you so much! but was wondering if you would be able to explain a bit further on how I could be able to answer this question 'Does retinal and cortical physiology support trichromatic colour theory, opponent processing theory, or both? ' xx

[@PsychExamReview]

Amelia Lewis Without going into lots of detail, you can think of Trichromatic Theory as supported by retinal physiology in that we do actually have 3 different cone types which are specialized for different wavelengths, while Opponent Process Theory is supported by antagonistic pairings that occur later in visual processsing. This is why these two theories can be seen as complementary, rather than contradictory.

[@samiajjohn]

Thank you, that makes sense!

[@PsychExamReview]

Amelia Lewis No problem, glad that made sense!

[@kevinsaldivar4276]

thanks bro gladly appreciated keep up the good work

[@PsychExamReview]

You're welcome!

[@khulanhulanka292]

May I know why do I look at some light on LED screens/ electronic candles which is supposingly just yellow light but sometimes I can see the red and green in it? I asked my friends if they do see it but it just seems that I'm the only one able to see the different colours within that 1 colour. Not all the time but sometimes I notice it. I'd appreciate if there is some reasoning :)

[@PsychExamReview]

To be honest, I'm not sure exactly why this might be, but there have been some studies looking at differences in the perception of the tint of white LED light. I imagine there might be several possible explanations for differences; different sensitivity to certain wavelengths or maybe differences in how wavelengths are refracted or absorbed as they pass through other structures of the eye (like the cornea or lens). Sorry I can't provide a more definitive answer, thanks for commenting!

[@MissK233]

Thank you so much! you're a lifesaver!!!!!!

[@PsychExamReview]

You're welcome!

[@violetrisaralda878]

Great video! Thankss

[@PsychExamReview]

You're welcome!

[@omartawfik5144]

Thank you so much for this, I am in University of London, psychology. I am suffering in biology do you have any tips?

[@PsychExamReview]

You're welcome. I don't know which areas are causing your suffering, but I'd generally recommend drawing as much as possible when learning biology. Your drawings don't have to be good or artistic, but attempting them will force you to pay careful attention to details and structures and should also help you to remember more. Let me know if this ends up being helpful!

[@samhuynh8925]

Thank you so much life saver!

[@PsychExamReview]

No problem, glad you found it helpful!

[@ezgitemel5539]

thanks Sir, it was very good

[@PsychExamReview]

You're welcome!

[@anjali1984]

Thnku♥️ love from india✨️👍🏼

[@lexjohnson0803]

Having a hard time studying after a long day. This video helped so much and I loved the examples. I was shocked at the woman in the bikini! So cool & thanks again for uploading!

[@PsychExamReview]

I'm glad it was helpful for you, thanks for commenting!

[@njokuchizoba5033]

Wow, it's quite explained Well

[@PsychExamReview]

Thanks!

[@chetansiddharthkumar9019]

What is Duplicity theory of vision? I am having confusion about it.

[@PsychExamReview]

Duplicity theory is just the idea that we have two kinds of photoreceptors which are specialized for different settings: rods for dim light conditions (night) and cones for bright light conditions (daytime).

[@MO-bx1yx]

Thank you ❤️😊

[@PsychExamReview]

You're welcome!

[@karandeepsingh1963]

wow thanks man...

[@PsychExamReview]

No problem! Thanks for watching!

[@TheWorldandTash]

Thanks so much

[@PsychExamReview]

You're welcome!

[@pieterjohannessebastiaangr3618]

Tank you for the information (and the almost naked lady)

[@PsychExamReview]

You're welcome!

[@sharlal6284]

you are so slay. studying for my biopsych exam. -2024

[@lenavoyles526]

But yellow is not the opposite of blue - orange is. So how does this opposition work?

[@PsychExamReview]

Blue and yellow are opposites in the additive RGB Color Model, which is based on cone types (red, green, and blue) as primary colors, while blue and orange are opposite in the traditional RYB color model which uses red, yellow, and blue as the primary colors. Hope this helps to clarify, thanks for commenting!

[@starrynight3009]

so, ghosts could pretty well be all around but if they reflect light of a wavelength that we cannot perceive, we cannot see them !

[@ankitagautam7190]

IDK if this question makes much sense but is it possible to visualize a color we 've never seen?

[@PsychExamReview]

This is a great philosophical question and not one I can answer, but I can suggest a few ways to think about it. One thought experiment for this is to imagine a person who is completely colorblind but who becomes an expert in the properties of light and color. Would this person be able to understand the experience of seeing the color red? If color vision was suddenly restored, would the person be surprised by how things look or not? Could a person with normal color vision ever explain the experience of certain colors to someone who is partially colorblind? Similarly, there are some people with 4 cone types who can differentiate colors that look the same to those with normal color vision. Can someone with normal vision ever understand these differences?

[@ankitagautam7190]

PsychExamReview I guess the answer to most of these questions is a ‘no’. Thank you so much for responding! You’re doing some great work!

[@PsychExamReview]

@@ankitagautam7190 Thanks, glad you appreciate it!

[@pandumurgumalla5913]

nice explanation Bro but I not understood properly, the opponent process theory

[@PsychExamReview]

Hi Pandu, opponent process theory is a bit complicated and I didn't go into detail on exactly how it occurs in this video. The basic idea is that cells can send either a green signal or a red signal (or a blue or a yellow signal) and can't see a mix. This is why we don't see colors such as reddish-green or bluish-yellow. The signal must be one or the other. In the color afterimage, half of the pair is "tired" so white light will temporarily appear to the be the opposing color. For a more technical video on opponent process theory you can check out Craig Blackwell's video here: kzbin.info/www/bejne/jJangKN9h7KNbbs I hope this helps, let me know if you have any other questions!

[@pkptl7636]

Must to see

[@Therapistyouknow]

The legendary blue/gold dress debacle explained?!

[@PsychExamReview]

The blue/gold dress is more related to how we make assumptions of lighting and this influences the colors we perceive. The dress can appear to be a black/blue dress in yellow lighting, or a white/gold dress in a blue shadow.

[@FaheemKhan-rp3uh]

"stare at X" confused me for a while......

[@peiqicheng4378]

宝藏博主！

[@jesshylan2724]

Great explanation but you couldn't have thought of a different negative afterimage? "Stare at the X, I know it's hard to do." Wtf? Was that necessary??

[@dazclean]

Thank you. You can teach me any day. 😁

[@PsychExamReview]

My pleasure, thanks for watching!

[@Browno747]

Sorry didn't see an X, just kidding! Very helpful video.

[@chuggyy]

"I know that's hard to do" AYYYYYYYYYE MAH BOI

[@Z3nHolEminD]

colors rock

[@fidrewe99]

Why red and green, why blue and yellow? Red produces a cyan afterimage, green produces a magenta afterimage and blue produces an orange afterimage. It can't be just L and M cones inhibiting each other, they must also be inhibiting S cones.

[@PsychExamReview]

Great question, I didn't explain this fully in the video. The reason that the after-images are seen as complementary colors (green/magenta, red/cyan, and blue/yellow) rather than simple opposing pairs is that the white light also contains other wavelengths. So if you fatigue green, then red is relatively stronger, but this apparent red is also mixing with blue wavelengths in the white light, so Red+Blue = Magenta. If you fatigue red, then the apparent green mixes with blue wavelengths: Green + Blue = Cyan This page has some demos you can try for complementary colors: www.animations.physics.unsw.edu.au/jw/light/complementary-colours.htm

[@jaidebeck]

the remote in front of my phone camera didn't work. :O It was working on my tv. :o

[@PsychExamReview]

Hmm...not sure if your camera isn't picking up the signal or maybe the remote doesn't use an infrared signal. I guess you can try with some other remotes and see if it works.

[@DANGJOS]

@@PsychExamReview That's not why. Most modern smart phones have an IR cut filter which blocks out IR signals. I have an old phone that can see the light because it doesn't have this filter. My newer phones cannot see it though.

[@PsychExamReview]

@@DANGJOS Thanks for the clarification, this has always worked even with my relatively new phone so I wasn't aware of these filters on some phone cameras. Thanks for commenting!

[@rohingeorge9178]

its hard to stare at the x!!! 😂

[@jenniferchandler9203]

You do such an amazing job explaining this that I was tempted to show the whole video to my AP psych class. Then, you chose to go in a direction at the end that means that I CAN NOT show the whole thing to my class. Please change the end. I respect your right to be a male but when you post an “educational” video - you have power. I will not grant you this type of power in my class. The girls are the best students in my class and I will not grant you the power to minimize them. Ug - be an educator the whole way through. Keep your personal life just that.

[@PsychExamReview]

I'm sorry you feel that way. I don't have any intention of minimizing any students in any way but I also don't see anything wrong with presenting a non-graphic image of a woman and making a few light-hearted comments suggesting that the woman in the photo is pleasant to look at.

[@PsychExamReview]

@@jillgiannios1624 Prudishness about seeing a woman in a bikini strikes me as an "extremely dated" idea too :)

[@PsychExamReview]

@@jillgiannios1624 I've seen women in bikinis in public educational videos by Jean Kilbourne, and it wasn't at the beach but on KZbin! Hopefully someone can stop her offenses to decency, modesty, and respect for the sake of psychology students everywhere. Is it all male gazes and just male desire that's a problem? Seems like gendered assumptions about who finds females sexually desirable. Heteronormativity is not woke at all bro. I am familiar with statistics on violence against both women and men. Your attempt to link my comments and a brief picture of a woman in a bikini to the real suffering and deaths of others is not only intellectually dishonest but it also trivializes the efforts of those who truly advocate for improved understanding of these issues by removing complexity and nuance and simply blaming gender norms.

[@mackenziepyke3293]

@PsychExamReview ​Of course you don't see anything wrong with the photo, it doesn't objectify you. It objectifies the female students watching this video. Those 'light-hearted comments' clearly weren't directed at female viewers either and blatantly exclude us from the discourse. It's also a super random vibe to bring into an educational video about visual theory.

[@PsychExamReview]

@@mackenziepyke3293 I have no problem with criticism of my decision to use this particular afterimage demo on grounds that it's a bit racy or not uptight-academic enough for some tastes or expectations (that someone had already created it, it was listed as open for reuse, and it fit on the available screen area may have also influenced my decision). But criticisms suggesting I'm promoting gender oppression are stretching things a bit too far. These attempts assume heterosexuality (to make a neat men vs. women dichotomy) and ignore that these kinds of images are commonplace and even expected in media which is predominantly viewed and purchased by women (suggesting that they can probably handle seeing a woman in a bikini). The majority of my students are female, the majority of my viewers are female, and the majority of people I spend time responding to and answering questions from are female. If I were trying to blatantly exclude female viewers from the discourse I'd be doing a pretty poor job. On a related note, this majority-female audience does mean I have been subject to some objectification myself (even in the comments section of this very video). Fortunately I don't think this is evidence that women are trying to exclude men from educational discourse, so I'll do my best to overcome it and keep making videos that help students, regardless of who they are.

[@diesel4338]

why do you use a top model pic and ask me too fix the × not possible bros hahaha 😂😂😂😂

[@mcovarrubiasc]

Great video, many thanks. It would be absolutely great if there was no use of women's body as a decor object. As expected: guys on the comments making sexist-daddy-jokes about that :(

[@navyadeepthi4541]

At <a href="#" class="seekto" data-time="316">5:16</a> did anyone here a sound from AMONG US???

[@abasu1013]

Good video, but it's slightly sexist to put up an image of a model and then say "I know it's hard to do"... You could quite easily use another more appropriate image.

[@zuziastradowska44]

very nice video, but the choice of the last picture was poor, you could've chosen any picture to just prove science instead of fulfilling your desires to look at a woman and commenting on how hard it is to focus on the x, it made the whole video lose its value to me

[@octaviomora9810]

whats her name lol

[@JoGamelsRockGoddesses]

Your speaking is so clear, but why did you need to use a picture of a woman pulling down her bikini bottom for your last illustration? It was distracting. I want to understand the theory, that's why i watched this video. Also, the woman who modeled for money should be paid for her hard work. It is copy right infringement, unless you have permission to use the image. Usually you stay on topic, but some primal part of the human brain got the best of you in this one.

[@RuhaniAngel-lc1wz]

amazing vid but could you maybe not use the images of potentially naked women, cause if my mum walks in she will never believe me that I was actually studying and that I'm also not gay😶

[@merlevm4365]

Nice explanation! But I think using that picture of a halfly naked woman is quite unprofessional and also commenting it in that way is really objectifying and sexist. I was a little shocked.

[@ghanashyamk5002]

Do u have sugar man why u gng fast... Make a understandable video

[@AFRoSHEENT3ARCMICHAEL69]

That humming you hear when he speaks is distracting

[@PsychExamReview]

My apologies for the low audio quality on some of these earlier videos

[@jillgiannios1624]

Why would such an intelligent man include such sexist and demeaning material ???? Not woke at all bro

[@Alindber1]

Seriously.

[@ExistenceUniversity]

Lol get over it

[@Bensnsnajebe]

*JESUS CHRIST LOVES YOU AND CARES FOR YOU HAVE A GOOD DAY EVERYONE*

[@mathewlopez]

You got this twin 🫂

[@jamesgalbraith12]

Thank you!

[@PsychExamReview]

You're welcome!