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  • plenty of people think of dogs as they're best friends, and the fact that we live with them so closely means that we get to know them pretty well.

  • But sometimes our furry friends can act in ways that air surprising, beguiling or downright mysterious.

  • And over the years we hear it's sideshow have answered a lot of questions about them like Ah lot, it turns out we all have a lot of questions about dogs.

  • One of the first ones that springs to mind is, Are they really color blind or is that just a misconception?

  • Turns out dogs can see color just not in the way that we do here is Michael with more?

  • Maybe you've heard that dogs can only see in black and white.

  • It's one of those fun factoids that people like to toss around sometimes.

  • But this, like so many things we talk about on quick questions, is a misconception.

  • And the misconception stems from the fact that dogs are, from a human perspective color blind.

  • But that doesn't mean they can't see color.

  • We perceive color through a series of receptors in the retinas of our eyes called cones, and humans have three kinds, each of which is activated by a specific wavelength of light, corresponding to a certain set of colors.

  • Most humans have cones that can detect blue, green and red wavelengths of light.

  • But dogs kind of like humans who are color blind on Lee have two kinds of cones that work for dogs.

  • The two colors they can register are blue and yellow, so dogs can't see the color red.

  • But they can see and distinguish between various shades of yellow, blue gray, and something that probably comes through is a dirty greenish brown.

  • So while we see this, your dog sees something more like this.

  • It's not exactly Technicolor, but it's a lot more information than just black and white and setting the record straight about dogs.

  • Partial color Vision is teaching us a lot about how pups experience the world.

  • Recent experiments have found that dogs who are trained to find dark yellow objects could still find them, even if they were replaced with very light yellow ones.

  • And they didn't mistake dark blue objects for the dark yellow ones, either, suggesting that dogs can clearly distinguish between many different shades and colors.

  • And don't just see in gray scale.

  • So the next time you ask your dog to fetch your blue slippers and he comes back with a pair of bananas, he's not color blind.

  • He's just messing with you.

  • If your dog is smart enough to pull a prank like that, you might want to recommend them for doggy MENSA.

  • Or you might want to enlist them to test that old adage that old dogs can't learn new tricks.

  • It's possible we believe that because older dogs don't learn as readily as puppies.

  • But research shows that teaching them new tricks could be a really nice thing to do for your senior pups.

  • Here's what the science says.

  • They say that you can't teach an old dog new tricks, but that's saying might not be as trustworthy as you'd think.

  • Past puppy hood dogs aren't actually set in their ways.

  • In fact, research shows that not only can old dogs their new tricks, but teaching them could be a really good way of improving their quality of life.

  • A few studies have investigated this specifically.

  • For example, a group of European researchers train JJ 265 dogs across multiple studies as recently as 2017 to push their noses against a touch screen.

  • It showed them pictures like flowers, cups and other things, and when the canines picked the right picture, they were given a treat.

  • It took the animals a while to really get the hang of the game.

  • But eventually even the oldest doggy participants cut on, and they could consistently pick the correct picture to get a treat.

  • While all dogs could learn to pick the right image, the researchers did notice that dogs over the age of 13 were much slower at learning than the younger ones.

  • And that's because dogs, like humans, take longer to learn things as they get older dogs.

  • Cognitive development parallels are is in some ways, just like kids seem to be faster picking up new languages than adults.

  • Puppies seemed to be generally quicker on the uptake than older dogs.

  • A 2014 study that tested 100 and 45 border collies on skills like memory and attention found the dogs faculties start to decline as they get older, maybe in a similar way that happens in humans.

  • They also found that older dogs were just generally less interested in new stimuli while puppies air curious about anything and everything.

  • Older dogs tend to lose interest in things more quickly or tune them out entirely.

  • So in order for older dogs to learn new things that you have to try a bit harder to capture their attention.

  • But even though it takes them a bit longer to learn new tricks, that doesn't mean it's any less important.

  • The researchers think that just like older humans can derive satisfaction from brain puzzles like crosswords.

  • Ah, bit of mental stimulation might be great for keeping older dogs healthy and happy.

  • A 12 year old dog might not have as much energy to play fetch as she did when she was a puppy, but she can still benefit from playing games.

  • And computer games like the ones used in these studies require less energy, so they might just fit the bill.

  • The researchers even suggested their experimental setup could potentially be adapted to let dogs play computer games at home.

  • So not only can old dogs learn new tricks, research suggests it's a great idea to try and teach them.

  • It may be a little tougher for them, but it seems to be worth the effort.

  • But what if your dog is tuckered out from a long day of educational computer games and just wants to chill for a bit?

  • You know, kick back and watch some YouTube?

  • You might have noticed your canine companion reacting to things they see on a computer or TV screen, suggesting that they can watch TV at least sort of.

  • It.

  • Turns out they don't see exactly what we do when they're looking at a screen, because TV screens are designed for humans.

  • But dogs actually process visual information a little differently.

  • Here's Hank with the details.

  • By the way, this clip has some brief flashing lights, So if you're sensitive to those, just skip ahead until you see me again.

  • Does your dog ever seem more excited for the next season of game of Thrones?

  • You are, or like weirdly into barking at nature documentaries.

  • If so, like a lot of our patri on supporters, you might have wondered whether your dog is really watching TV or if you're just reading a little too much into things.

  • So science is here to tell you that they are probably watching it, but they aren't seeing exactly the same thing you are.

  • Some dogs just seem to love watching TV.

  • Watching habits can vary by breeds.

  • Some, like hounds, are mostly motivated by smells, so they're less likely to be interested in the scent free images on a screen.

  • Hurting Dogs, on the other hand, tend to get excited when they see movement, so they may be more readily drawn to video.

  • But regardless of breed, what dogs see on this screen is definitely not what we see dogs.

  • Visual systems are much more sensitive to flickering, which helps them perceive movement more efficiently.

  • So if you were to start flashing a light on and off slowly and then ramp up the speed, you'd stop being able to distinguish the flashes when it's flickering faster than 55 times per second.

  • Beagle, on the other hand, concede pulses that flash upto around 80 times a second.

  • The image on a gold standard TV screen refreshes about 60 times a second, fast enough that we can't see the individual pictures but too slow to fool our furry best friends.

  • So your pop, your favorite show might look less like a video and more like dancing in a very fast strobe lighter thumbing through a flip book.

  • And that's not the only part that might underwhelmed them.

  • No matter what type of TV you have, what might look like a vibrant, colorful image to you could be pretty meth for your dog.

  • That's because a typical scene uses a lot of Hughes that they can't distinguish instead of having three different color receptors in their eyes.

  • Like us, Dogs only have two, so they only see worlds in shades of yellow and blue.

  • But if you really want fight our spot to be able to enjoy TV with you, science has some tips.

  • There's nothing you could do about the colors, but you can get a new TV if you've been holding out on a lot of modern TV's.

  • The image on the screen changes more than 60 times for second.

  • You can also choose shows that your furry best friends will find more engaging.

  • Dog's gonna be drawn into watching videos by noises they already find intriguing, like barking or toys, squeaking and unsurprising that they seem to like watching other dogs, which is why we're gonna have a new size show hosted only by dogs.

  • Four dogs just dogs that's it.

  • You probably want to go for live action, not cartoons like Lassie, not Clifford.

  • Dogs are intelligent enough to recognize photos and videos of dogs and other animals, which might be why they don't respond so well to animation.

  • Probably don't look enough like the real thing, but maybe we have anecdotal reports from inside the studio that it does work in at least one dog if you really want to go all out.

  • There are even satellite TV channels with programming designed for dogs.

  • The brightness, colors, sounds and camera angles are specifically chosen to appeal just to them.

  • What?

  • But if your dog is not interested in TV, don't sweat it.

  • Researchers haven't actually looked to see how screen time effects dogs, so we don't know if it has any consequences long term.

  • And you might think your dog is already enough of a couch potato.

  • In any case, they'll probably be Justus.

  • Happy may be happier if you go on a walk, and that's good for you, too.

  • We've all probably heard that if we love our dogs, we shouldn't give them chocolate, even if they see us enjoying it and seemed to promise that they would love it to please, just a little taste.

  • Once again, this comes down to a key difference between humans and dogs, this time in how our digestive systems process the foods we've adapted to eat.

  • Here are the details.

  • If you have a dog, you've probably heard that chocolate will make your pet sick, and that also applies to other pets, like cats, rats and mice.

  • But that just doesn't seem fair.

  • Why don't we get to go to town on a giant bar of dark chocolate?

  • But Fido shouldn't even have one bite.

  • It all has to do with a molecule called thehe Bro mean, which is made up of carbon, hydrogen, nitrogen and oxygen atoms.

  • And along with its partner, caffeine is one of the many reasons humans have loved chocolate for thousands of years.

  • Both molecules are dangerous for dogs, but chocolate contains a lot more Theo Bro me, and then it does caffeine, so it's the molecule to watch out for, like caffeine.

  • Few bro Ming is a type of alkaloid, which is a huge class of molecules that generally contain rings with at least one nitrogen atom in them, and alkaloids often have physiological effects on humans and other animals also like caffeine, feel bro mean makes our hurts pump faster or blood vessels dilate, and some of our muscles get more energy, which sounds great.

  • But too much of it can make our hearts pump too quickly.

  • And our muscles contract uncontrollably, eventually leading to nausea, convulsions, heart attack and even death.

  • Luckily for our taste buds, we humans process Theo bro mean pretty quickly, so that's not something you have to worry about.

  • It rarely sticks around long enough to cause any harm, but our pets aren't so lucky.

  • They process Theo Bro Ming a lot more slowly so we can easily build up and cause those dangerous effects.

  • It's hard to know exactly why we evolved to be better at digesting Theo Bro, mean, But it might be because alkaloids mostly come from plants and our ancestors ate a lot more plants than early cats or dogs did.

  • Whatever the reason, the same amount of Theo Bro means stays and pets bodies much longer, giving it more time to pile up and cause harm.

  • On top of that, most pets are a lot lighter than humans, so it really doesn't take much chocolate to make them sick.

  • Cats don't often get poisoned from chocolate because they can't taste sweet things, so they're generally not too interested in it.

  • But dogs sure are.

  • Your average adult human would need to eat about eight kilograms of dark chocolate to get a lethal dose of Theo Bro Me, but a medium sized dog would only need to eat about one kilogram, and a house cat would only need 1/10 of a kilogram.

  • Sweeter chocolates have less Theo Bro me.

  • And so the lethal doses higher about five kilograms of milk chocolate for dogs and about 1/3 of a kilogram for cat so they'd be sick long before eating that much.

  • Meanwhile, you and I would have to eat about half of our body weight in milk chocolate for a lethal dose, which might sound wonderful.

  • But I don't want to see any of you writing challenge accepted in the comments, because you'd be very sick way before finishing that much talk.

  • Among other things, I'm trying very hard not to picture what that would do to your digestive system, but the next time you decide to indulge in a chocolate bar or three.

  • Just keep it to yourself no matter how long your dog gives you those adorable puppy eyes.

  • But how in tune with our emotions, are they really?

  • Do they know we're sorry we can't give them chocolate?

  • Or what about the old bit of folk knowledge that dogs can smell fear?

  • There's actually a bit of research to back that one up.

  • It's possible the dogs really can sense certain emotional states, thanks to the chemistry of our sweat.

  • And they're incredible sense of smell.

  • At least maybe here's Hank to tell us about it.

  • If it hasn't been said to you, you've probably heard it on TV or in a movie.

  • Stay calm around strange dogs because they conspire Mel Fear and they might attack.

  • But until recently, scientists hadn't looked to see if that was true.

  • Now we know that they can smell fear, but when they do, they don't get aggressive.

  • They actually get scared.

  • Two dogs have amazing noses.

  • Their sense of smell is 10 to 100,000 times better than ours, which is why they can help us detect traces of chemicals from bombs, drugs and even people buried under the snow That's thanks to the sheer number of olfactory receptors they have up to 300 million compared to our measly six million and the fact that relative to their size the part of their brain that analyzes smells about 40 times the size of ours.

  • But even so, dogs don't rely entirely on their sniffers when they want to communicate with each other or with us.

  • That usually can use body language and vocalizations as well.

  • When we tell them there's such a good dog, Oh, they process the tone of our voice and the words that were speaking in different brain areas, just like we do another human's talk.

  • Which means they do understand what we're saying to some extent.

  • And we know that dogs are good at picking up on physical signals.

  • In fact, studies have shown that they can differentiate between our emotions based off of our faces and body language.

  • So for a while, most scientists and dog trainers figured that dogs don't need to sniff out our feelings.

  • They can see it in our posture and hear it in her voice.

  • It wasn't until recently that researchers looked directly into whether dogs can smell fear when we're afraid.

  • The sweat we produce contains different chemicals than when we're happy or sad, because the composition of our blood changes in response to hormonal signals.

  • So scientists can stick swabs in our armpits while inducing different emotions and then see how dogs react to those odors.

  • And they did this in a 2016 study published in behavioral brain research and then found that dog's heart rates increased when they sniff sweat from people who watch a scary video suggesting that they can smell fear.