Naked Science Forum
General Science => Question of the Week => Topic started by: thedoc on 22/06/2010 18:47:19
-
Why can't dogs watch CRT-style TVs? Can they see the images on LCD and LED TVs?
Asked by Tom, Wales
Hear the answer to this question on our podcast (http://www.thenakedscientists.com/HTML/podcasts/show/2010.06.20/)
[chapter podcast=2713 track=10.06.20/Naked_Scientists_Show_10.06.20_6552.mp3](https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.thenakedscientists.com%2FHTML%2Ftypo3conf%2Fext%2Fnaksci_podcast%2Fgnome-settings-sound.gif&hash=f2b0d108dc173aeaa367f8db2e2171bd) or Listen to the Answer[/chapter] or [download as MP3] (http://nakeddiscovery.com/downloads/split_individual/10.06.20/Naked_Scientists_Show_10.06.20_6552.mp3)
-
We posed this question to David Williams, an Ophthalmologist at Cambridge Vet School...
David: - When we look at a picture on TV or the film in the cinema, it seems that we are seeing a complete flowing image. But actually, what we’re looking at is lots of individual frames. They seem to flow together because our eyes don't notice the change from one image to the next. [img float=right]/forum/copies/RTEmagicC_Terrier_mixed-breed_dog_01.jpg.jpg[/img]Old fashioned TVs and films produce images at about 24 frames every second and that’s fine for people because we have what we called a ‘flicker fusion frequency’ how quick the image needs to change of about 16 to 20 times a second. But when we looked at dogs, we looked at them behaviourally. It’s shown that their flicker fusion frequency is a lot higher than ours, maybe 40 to 80 frames a second. That means that when a dog’s looking at an old fashioned TV or a movie, it would see it to be flickering a lot.
If you look at modern plasma screens and digital TVs, they renew their images a lot faster, maybe up to a thousand times a second. So theoretically, our pets should be able to see things a lot better on more modern TVs, but that’s just a theory. Science needs the evidence, doesn’t it? What’s the evidence? If you type in dog watching TV onto YouTube online, you’ll find nearly 4,000 results and most of them will convince you that actually, most dogs certainly react to animals easily on a TV screen, sometimes quite dramatically. But of course there, the trouble is we don't know what sort of TV is being used, do we? And how much do other confounding variables will say – things like sound that the animal might be reacting to rather than just the pictures. So it’s not much of a controlled experiment. But just watching the reaction of the dogs on those video clips on YouTube shows to my mind convincingly that dogs are reacting to what they see on TV even if we can't be quite sure what they're seeing. You know what? I’d like to say, if you've put a dog or a cat that loves watching TV and lives very near Cambridge, would you contact me? David Williams at Cambridge Vet School so we can do a bit more research to look further into this in a bit more controlled way.
Diana: - It seems likely that dogs can watch new, high refreshed rates televisions. I'm probable that old CRT TVs would simply have appeared too flickery for them to make out a moving image. And on the forum, JP said that their dog would certainly react to seeing and hearing another on a CRT screen. So much so that she tries to run around the back of the TV to find the other dog.
-
I had a dog that used to watch a CRT television. I've heard dogs can't see images on the screen the same way we can (the color and frame rate are designed for human eyes, after all), but she was certainly entertained by what she saw and heard. I do remember that if a dog was on screen, she'd jump up and bark, then run around to the back of the television trying to find the other dog.
-
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F&hash=3cd4f4119996b42d10f5ed9eb0e8d712) [ Invalid Attachment ]
http://web.orange.co.uk/article/quirkies/Scientists_Monkeys_like_TV (http://web.orange.co.uk/article/quirkies/Scientists_Monkeys_like_TV)
That explains the ratings for "Big Brother" [:)]
-
That's a great story - unfortunately I couldn't get hold of the journal article to read the real science rather than the journalistic news hype, but it certainly sounds interesting.
Chris
-
unfortunately I couldn't get hold of the journal article ...
http://www.frontiersin.org/neuroscience/behavioralneuroscience/paper/10.3389/fnbeh.2010.00031/pdf/
[BTW the photo in my previous post is not from the study, it's a work of art by "Banksy" (http://news.bbc.co.uk/1/hi/in_pictures/7662797.stm)]
-
Thanks - and the image is hilarious!
-
We've got two dogs. One, a mellow yellow lab, absolutely ignores the television. The other, an Australian Shepard mix, once almost destroyed the set while watching a show about sheep (Sorry Neil). This dog gets excited when it sees any animals on the telly (both a CRT and a plasma).
-
Thanks Bass, this vindicates me in a discussion we were having in the office about this; I said that my mother's black labrador goes nuts when a dog appears on her television (which is a CRT-based set). Everyone else scoffed and suggested that it was because of sounds accompanying the pictures; but if you have one dog that ignores the telly and another that simultaneously responds to it, this suggests it's more to do with the ability of the animals to see what's on the screen.
Chris
-
Some dogs apparently misinterpret their reflection as another dog (even in a TV screen (http://www.youtube.com/watch?v=_uO9-8Lr640)) so there is visual recognition: it's not just sound of dog on TV.
-
No, the instances to which I am referring are definitely not like this; in all cases our dog did not move his position and had been paying little attention to the TV until another dog appeared on the screen, running along in the background; at this point he went mad. Other animals appearing on-screen did not receive the same treatment, indicating that the response appears to be dog-specific.
I'm convinced he could see the dog on the screen, but what's interesting are two aspects to this:
1) That a dog knows what another dog looks like and recognises it as such.
2) That the size of the dog on screen is obviously smaller than real life, yet the dog still reacts to it as a dog.
Chris
-
Everyone else scoffed and suggested that it was because of sounds accompanying the pictures
My reflection example (http://www.thenakedscientists.com/forum/index.php?topic=32150.msg313135#msg313135) was to illustrate that dogs don't just respond to TV sound, (unlike TV reflections are silent).
-
One afternoon I was at my friends house with my new video camcorder. I took some footage of his Shepard collie playing catching Frisbee nose coming up to the camera etc with full sound.
I figured he could have it for the future looking back.
That evening we sat back to watch the entertainment. The dog was in the kitchen, as soon as I started to play the tape, the first sound from the tape was her barking.
She ran directly to the TV. As soon as she seen her image on the screen she yelped and ran behind the sofa to hide. The dog actually had a physiological episode and my friend told me no more recordings of my dog.
This is one dog that seen and heard the TV
-
Dear Dr's Karl and Chris,
"Dogs can't watch a TV with a CRT" ?!!
What rot!
Look at this clip of a dog watching an old-style TV with a CRT and tell me he doesn't understand what's going on.
He's quite quiet till there's a dog on TV, and he clearly recognises it.
I also know from experience that a cat has some understanding of TV (with a CRT - I have never had a flat screen TV). Cats aren't very demonstrative, but mine used to get quite animated if there were little furry animals or birds on the screen, though I think they may just be interested in something moving on the screen, looking like potential prey, and mice and birds probably peak their interest because of the way they move. On one occasion, however, there was a cat food advert on. It showed a close-up of a cat eating from a dish. My cat looked at it and kind-of 'clapped' his mouth, making eating noises. I don't think this is just the doting owner talking - I was very convinced that he had understood what he was seeing.
I one heard a program in which they were talking about the world of scent in which a cat lives, and how cats never pay any attention to a mirror because they don't recognise the "other" cat because it doesn't have a smell. In fact, young kittens get very animated the first time they see themselves in a mirror, but the effect doesn't last long before they recognise a mirror for what it is and ignore it after that. I think the same probably applies to both dogs and cats when watching TV. It has some small effect, but mostly, they've seen it all before. Maybe it's the stupid ones that pay attention - because they haven't figured out that it isn't real.
Best regards,
Mike Collins,
Basingstoke.
-
This video is amazing, so the dog really understands what he is watching on tv… guys its hilarious truly magnificent and mind blowing…. He is selectively reacting to what is on the screen. It is sort of like a human being which is trying to see 3D TV by means of those old blue and red glasses… truly amazing!!
-
i can find an exact and nice explnation from mr. David Williams. thank you sir.
-
My dog responds to dogs on both CRT screens and digital TV screens even when the sound is off. She paws the screen, barks, then runs behind the TV to see if the dog is there. She can also distinguish dogs from other four-legged animals such as horses, deer and cats. In the latter cases, she approaches the screen, watches intently but quietly until she is satisfied that it is not a dog on the TV. She responds 100% of the time when there is a dog on screen.
-
I am currently designing an experiment for my BSc Animal Management dissertation to determine if dogs can learn from a demonstrator dog they see on television. I'd love any input:)
-
I have two dogs at home. One of them, a rotweiller completely ignores the television. But the other, a Vizsla loves watching tv. She reacts to all animals she sees. When a dog or cat appears on the screen, she will jump off the sofa and bark and try to 'catch' the animal on the screen. She also loves watching children comics. The funniest time was when my two grandchildren were sitting in front of the tv, with my Maya sitting between them , watching a comic and all three heads would follow the action at the same time. When watching a nature program one day about tigers , when she saw them on the screen she started whining and acting scared , and sat close to me the whole time. I do believe that some dogs see what is on the screen. I also had a Great Dane who would try to follow the flight of birds on the screen trying to see where they had gone in the room , or run behind the television to see if the dog she had seen on the screen was outside.
-
For dogs and cats a CRT would probably be like staring at a lightbulb. For best results I've found the LED tv's to get the most dramatic visual responses with the volume turned off. For example: load up a high speed video of black and white pong and turn off the volume midway. So far I've seen 6 dogs and 4 cats track the pong ball on an LED screen. Not so successful with other types. CRT screen has almost no success in the animals tracking the movement of the ball. I've since turned the brightness and contrast down quite a bit and my dog watches movies with me now like he never has before. He enjoys the action scenes but still ignores the human drama.
-
I can't use the wii with my dog in the room, because he tries to eat the finger pointer on the screen. Opens his mouth and sacks his face into the screen wherever the pointer is at, even on mute. So he definitely sees it.
-
My Cavalier King Charles spaniel barks at every dog, cat, child and wildlife on my HD LED TV. When visiting my mother, who has an old CRT TV, he responds to nothing, even though it is at his height and he lays on the floor right in front of it.
-
Yes, they're like babies as well, They love anything colorful and moving things. They enjoy watching LED Display tv's.