When television shows and movies show events from a dog’s point of view, they usually switch to black-and-white. Dogs, like most mammals, actually do see colors—though not quite the same way humans do.
Human eyes contain photoreceptor cells called rods and cones. While both detect light, cones respond to specific wavelengths and are responsible for our color vision. Humans (and other primates) have three types of cones that can detect the red, yellow, and blue wavelengths. Dogs, on the other hand, only have two kinds of cone cells: yellow and blue. This means they have no trouble seeing shades of blue and yellow but have trouble differentiating them from red and related hues. To a dog, a red ball will simply appear to be a shade of green, similar to what a red-green colorblind human might see.
People who compete with dogs in outdoor sports often recommend certain colors for equipment based on what the dog will see. Although a human may have an easy time spotting yellow agility equipment on green grass, a dog will struggle to differentiate the colors. Instead, agility experts often choose shades of blue, which will usually stand out against greens and other colors in the yellow spectrum.
Dogs mostly rely on their sense of smell and hearing, which are both superior to our human senses. They still use vision, though, and can see colors—just not as many as we can. Understanding how our pets see the world can help us make things easier for them. Utilizing contrasting colors, for example, may help a dog find a toy during fetch or improve reaction times in canine sports. One day we might finally see an accurate depiction of dog vision in media, with shades of blue and green instead of greyscale.
photo: Adrian Smalley (CC)
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The “five second rule” is an unofficial pass to eat food dropped on the floor—provided only a few seconds have elapsed. The general wisdom is that it takes several seconds for bacteria to transfer to the food item, making it safe to eat if picked up quickly. In one survey, 87% of people admitted to eating dropped food at least once. The five second rule was never backed up by science but some researchers have decided to test the idea.
In the first major study, researchers tracked the transfer of common bacteria, including E.coli, to food after it had been dropped. They found that carpet was less likely to transfer bacteria than smooth surfaces. While moist foods could become colonized within seconds, most foods were declared safe. For dry snacks, such as cookies, it could take 30 seconds or longer for bacteria to show up. The researchers decided that the five second rule works—in specific cases. (more…)
A placebo is a sugar pill or similarly ineffective treatment used in medical studies. The placebo acts as a control for comparison when studying the effectiveness of a proposed treatment. Often, patients will notice some improvement in their condition even when taking a placebo. This phenomenon is called the “placebo effect” and recent research is increasing scientists’ understanding of these events.
Deception isn’t necessary
Originally, it was believed that placebos only worked because patients thought they were being treated. In one study, patients with irritable bowel syndrome were treated with placebos. One group was told they were given a placebo with no additional information. The other group was also given placebos but the pills were described as follows:
“Placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes.”
Both groups showed some improvement but the group given more information had significantly higher global improvement scores. The authors concluded, “Placebos administered without deception may be an effective treatment for IBS.”
The reverse phenomenon is called the “nocebo effect”
If a patient doesn’t think a treatment will be effective, they may experience a worsening of symptoms. This has been called the “nocebo effect” in medical literature. The effect can also be caused by doctors and other clinical staff. If the doctor feels negatively about a treatment or mentions likely side effects, it may affect the patient’s perception. This can cause an ethical dilemma. Doctors are required to properly inform patients of possible side effects or risks. Emphasizing the negative aspects of a treatment may make it less effective, however. More communication training in medical school may help physicians keep patients informed while also framing treatments in a positive way.
How a placebo is administered may change the effects
Some placebos work better than others and the method of administration can increase or decrease effectiveness. In one study, large placebo pills were found to be more effective than small ones and two doses worked better than a single dose. Sham surgeries and injections tend to elicit a stronger placebo effect than a sugar pill. In one study, a sham surgery was just as effective as an actual arthroscopic partial meniscectomy (a surgery used to treat knee osteoarthritis).
Placebos can be considered a viable treatment
Placebos are so effective in certain cases that some researchers have begun to recommend them as treatments. In an analysis of 130 placebo studies, one research team concluded that while placebos don’t work for many diseases, they were effective for pain. Placebos successfully treated pain in 27 different studies of various sample sizes.
Interestingly, placebos can also help treat symptoms of Parkinson’s disease. There have been multiple studies but one in particular stands out. Patients showed significant improvement when they were treated using deep brain stimulation, a technique that involves stimulating the brain with electrical impulses. The treatment was only effective when patients were also given a placebo and told that it was an “antiparkinsonian drug”. Patients who didn’t receive a placebo showed little to no improvement. A similar experiment was later conducted with identical results.
The placebo effect is still poorly understood and the use of a placebo can raise ethical concerns. Placebos may help treat pain, for example, but informed consent prevents a doctor from prescribing sugar pills. At the very least, placebo research provides insights into how expectation and perception can affect the outcome of medical treatments.
Cold season is upon us and even the latest scientific technology can’t prevent us from catching a cold. The lack of a real “cure” has led to all sorts of crazy remedies, including Epsom salts and onions (even I don’t know what’s going on with those!). There are a few major misconceptions surrounding the common cold and I’d like to knock them out one at a time.
Antibiotics will help my cold go away
Colds are usually caused by a group of viruses called rhinoviruses. There are hundreds of viral strains that can cause a cold and these strains change from year to year. This makes it difficult to create a single “cure” for colds. There’s also a reason your doctor can’t simply prescribe antibiotics: they won’t work. Antibiotics only kill bacteria, not viruses. Viruses, including influenza, tend to be trickier to treat. There are some antiviral drugs out there but the most effective defenses against viruses are vaccines. Unfortunately, we don’t yet have a vaccine for the common cold. Since colds are caused by a variety of constantly mutating viruses, it’ll be a while before we see any real preventatives.
Vitamin C will cure my cold
Vitamin C is commonly touted as both a treatment and preventative for the common cold. The idea is that vitamin C supplements will boost your immune system, preventing you from catching a cold (or treating one you already have). Actual research, however, doesn’t support this theory.
There have been multiple studies designed to look for relationships between vitamin C and colds. Currently, there is no evidence that vitamin C will actually prevent a cold. A vitamin C supplement is also unlikely to treat an existing cold. In an analysis of 55 different studies, a research team concluded, “The lack of effect of prophylactic vitamin C supplementation on the incidence of common cold in normal populations throws doubt on the utility of this wide practice.”
There was only one case where vitamin C supplements helped prevent and reduce the duration of cold symptoms. The supplements appeared to help one group of people: those who were already deficient due to lifestyle. Patients who regularly engaged in rigorous exercise benefitted mildly from vitamin C supplements. The same was true for people exposed to extreme temperatures. In both groups, colds were less frequent and symptoms were reduced when participants took vitamin C tablets. In conclusion, a vitamin C supplement won’t help your cold unless you’re a marathon runner or work outside in frigid temperatures.
You should “sweat out” a fever
There’s a strangely common belief that you should purposely sweat during a fever. Proponents of this method will recommend wrapping in blankets, keeping the thermostat turned up, and drinking hot beverages. The idea is that by maintaining a high body temperature, you can kill the virus faster. That’s not how fevers work, however. Fevers are a symptom of your body’s immune system fighting off something—whether a virus, bacteria, or some kind of toxin. The high temperature alone isn’t killing anything and most fevers go away on their own within a day or two. Doctors generally recommend resting, staying hydrated, and taking an antipyretic medication (such as ibuprofen) if the fever is especially bad.
Cough syrup reduces coughing and helps sore throats
I was guilty of believing this one for a while. Most of us know that cough syrup won’t “cure” a cough but we expect it to at least help, right? The general consensus is that cough syrup will reduce coughing and help soothe a sore throat. However, there is very little scientific evidence for these claims. An analysis of commonly available over-the-counter cough syrups found that most of them had the same effectiveness as a placebo.
In a 2007 analysis of codeine, a common ingredient in cough medicine, the authors concluded, “Recent placebo-controlled studies have shown that codeine is no more effective than placebo in suppressing cough caused by either upper respiratory disorders or chronic obstructive pulmonary disease.”
Dextromethorphan is the only cough medicine with any scientific backing. It’s been proven slightly effective but only in adults; studies have shown that the drug is ineffective in children. The benefits are also small enough that some doctors question the value of taking the medication. Interestingly, pure honey provides mild cough relief and was found to be more effective than cough syrups in the same study.
Why do so many of these myths persist? Cold symptoms don’t last long for most people. If someone takes cough medicine and then begins to feel better after a day, they might believe that the medication helped. In reality, the cold symptoms would have improved on their own thanks to the body’s immune system. The best “cure” for the common cold? Time.
Photo: Mike Mozart / MiMo
By Erica Geiger
Nature documentaries can provide insights into the natural world and behavior of wildlife. Although often educational, they are still a form of entertainment. Reality TV shows are known for being staged but few people realize just how often nature documentaries are faked.
Stories Are Compiled Using Footage from Different Animals
Footage from different shoots can be weaved together to create a cohesive story. It’s difficult to track the same animals, especially over great distances. Instead, multiple animals play the roles of the various “characters”.
Chris Palmer, an ex-producer of nature documentaries, writes in his book that this tactic was used in the film Whales. Throughout the film, two whales named Misty and Echo are followed as they migrate over 3,000 miles. In reality, the story was told using footage from different whales. The whales seen at the end of the documentary are not the original whales filmed in the beginning.
Rented Animals Are Common
In many cases, the animals seen in documentaries aren’t even wild. This saves the crew time and money but can also be better for the animals in question. Rented animals and premade sets can spare wildlife from extra stress, which is especially important when filming endangered species. Some shots are impossible to get without captive animals. The problem is that nature documentaries never give any indication that they’re using rented animals.
The BBC used captive polar bears from a Dutch zoo in an episode of Frozen Planet. The scene, supposedly of a polar bear giving birth in the Arctic, was actually shot on a premade set. The den was built by humans, not the bear. The BBC said it was “standard practice” in nature documentaries. They defended their actions by pointing out the impossibility of trying to film a wild polar bear giving birth. The show never mentions any of this, however, and many watchers felt misled.
The IMAX Documentary Wolves had a similar birthing scene and also relied on rented animals. The den was artificial and the wolves used in the documentary were all captive animals. An episode of Life used captive-bred clownfish in an aquarium for one of their scenes. In Blue Planet, a lobster spawning scene was shot using lobsters in a tank. No matter the type of nature documentary, rental animals tend to be used whenever possible.
Feeding Scenes Are Nearly Always Staged
For scenes that involve animals feeding on carcasses, the film crew employs a few different strategies. The carcasses are normally planted; a nature documentary producer admitted to using road kill to lure wild animals. This isn’t always enough to entice the local wildlife, however, since most animals prefer fresher meat. Filmmakers get around this by adding treats, including M&M candies, to the planted carcasses. This can cause a feeding frenzy, encouraging animals to dig in as they look for the treats.
In some cases, the animals used for feeding scenes were captive-bred. In one documentary, tame bears were directed to carcasses by their trainer. The bears were further encouraged with treats. This is much safer than filming wild bears, which could become aggressive while feeding.
Lemmings Don’t Commit Suicide
Unfortunately, past nature documentary fakery wasn’t always harmless. The one fact most people know about lemmings is that they hurl themselves off cliffs in an act of “mass suicide”. Lemmings do migrate and they might occasionally fall off cliff sides, drowning in the process. They certainly don’t kill themselves in droves, however.
White Wilderness, a Disney nature documentary released in 1958, is responsible for this myth. The documentary shows footage of a group of lemmings jumping to their deaths. The narrator states, “A kind of compulsion seizes each tiny rodent and, carried along by an unreasoning hysteria, each falls into step for a march that will take them to a strange destiny.”
In reality, the lemmings were captive animals that had been rented by the crew. The scene was filmed in Canada, not the lemmings’ native habitat of the Arctic. As for the suicidal behavior, the film crew used turntables that pushed the lemmings, causing them to rush and eventually fall off the cliff.
Thankfully, today’s documentary fakery is usually done out of convenience or respect for wildlife.
Photo: Eelke (cropped)
By Erica Geiger
The United States dietary supplements industry is huge, bringing in over $20 billion in sales every year. Since 2004, the industry has seen rapid growth every single year. More than 80% of adults buy supplements annually. The U.S. Food and Drug Administration, however, doesn’t regulate these products the same way they regulate food and medications. This has resulted in mislabeled supplements, outrageous claims, and one study found that many natural supplements didn’t even contain the products they advertised. The FDA does have rules in place but it’s mostly up to the individual companies to regulate their own products.
With the lack of FDA regulation, companies can make all sorts of claims about their supplements. Unfortunately, not many of these claims are backed up by actual science. A common claim is that certain supplements can improve memory and learning. While it’s true that there are practices and substances capable of affecting memory functions, they’re not quite what you’d expect.
Ginkgo is commonly touted as a memory enhancer. Tablets, capsules, and tinctures are available at most stores, with marketing claims such as “Improves Memory” and “Enhances Mental Alertness”. Actual science says otherwise. In a large 2012 study, researchers found absolutely no difference between ginkgo and a placebo during both learning and memory exercises. Ginkgo also had no effect on mental attention. The authors concluded, “We report that G. biloba had no ascertainable positive effects on a range of targeted cognitive functions in healthy individuals.”
While ginkgo might not help you on that next exam, there are a few other things you can try without spending money on supplements.
If you’re trying to remember something or learn a new skill, exercise might be better than any supplement on the market. In a very recent study, a group of human volunteers were taught picture-location associations and then quizzed to get a baseline score. Some participants exercised right after the recall test, some exercised four hours later, and the last group didn’t exercise at all. 48 hours later, all participants were retested. The researchers found that the delayed exercise group performed better than average. There was no significant difference between the other groups. The group that exercised four hours after learning also had increased activity in the hippocampus, a part of the brain associated with memory and learning. Other studies had already linked exercise to improved memory but this one showed that it works best if you wait a few hours first.
There have been many studies on how music affects memory and learning. Results have been mixed but it appears that classical music, at the very least, can have positive effects on working memory for adults. In a 2007 study, researchers tested adults using working memory tasks. Working memory is what you use, for example, when trying to memorize a definition. In the study, one group listened to Vivaldi’s Four Seasons, another group listened to white noise, and a third group worked in silence. Participants who had listened to Vivaldi performed significantly better on memory tests. Music may not work for every type of learning but it’s at least worth a shot when trying to memorize something for a test. Note that current studies have generally used classical music (Vivaldi is actually the standard for these types of experiments), it’s unknown how other types of music affect memory.
Most people assume that proper sleep makes it easier to learn (and it’s true). Something that not everyone knows, however, is that sleep is actually critical for memory formation. While we sleep, memories we’ve formed during the day are strengthened. In past studies, a good night’s sleep was found to significantly improve performance in various tasks, including beating video game levels and learning to play new songs on the piano. During REM sleep, your brain is active and works with your memories, often linking them to previous ones. This partially explains why studying the day of the exam, even if you slept fine, isn’t as useful as studying the night before.
Let’s say you have an important exam coming up. You listened to classical music while studying, exercised a few hours later, and got a great night’s sleep. Getting a good breakfast will at least help your mental alertness and you can potentially sneak in one last memory enhancer–cinnamon. Cinnamon, which you probably already have at home, is more likely to help your memory than any of the expensive supplements at health food stores. In a recent study, mice that consumed cinnamon showed improved memory and learning ability. Specifically, the researchers were able to convert “poor learners” (mice that had performed badly on memory tests) to “good learners” by giving them a small daily dose of ground cinnamon. Cinnamon contains a compound called sodium benzoate that stimulates neurons in the hippocampus, improving memory and learning. The study hasn’t been replicated with humans yet but hey, there’s more evidence of cinnamon helping your memory than gingko and ginseng!
Photo: Sam Mugraby, Photos8.com
By Erica Geiger
Almost everyone has heard of evolution and most of us have a vague idea of what it means. Animals with useful traits survive and pass on their genes. Over time, these positive traits become more common and a species evolves. Most of us aren’t scientists, though, and a number of evolution myths have popped up over time.
Myth #1: Evolution is “just” a theory
We usually think of theories as being possibilities, not facts. A “theory” in science, though, takes on a different meaning. I personally like this definition from the National Academy of Sciences:
“a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses”
In other words, a scientific theory is an explanation that has been backed up by many studies and a substantial amount of evidence. We don’t call it a “fact” because science can always change as we learn new information. We’re all pretty sure the Earth rotates around the Sun yet that concept is called the heliocentric theory. It’s pretty unlikely we’ll find any evidence that goes against this “theory” but scientists still don’t call it a fact.
Myth #2: Humans evolved from monkeys
This is a common one and often used in an attempt to discredit evolutionary theories. It’s also not true; humans did not evolve from monkeys. We did share an ancestor with African apes (note that “apes” aren’t monkeys) about 8 million years ago but that doesn’t mean we evolved from them. Instead, there was a great ancestor that eventually gave rise to humans and apes. We’re most closely related to chimpanzees because of this ancestor but there were two distinct evolutionary paths.
When the human species began to evolve, the chimpanzee species was evolving separately. We’re related, we didn’t directly evolve from any modern primate species. We do share over 90% of our DNA with non-human primates, including gorillas and other great apes. On the other hand, humans also share 90% of their DNA with mice! That doesn’t mean humans evolved from mice, it’s just a result of most mammals sharing genes.
Myth #3: Survival of the fittest means the strongest will survive
Sometimes people will use the term “survival of the fittest” to excuse a behavior. I’ve unfortunately overheard someone say that we shouldn’t help those weaker than us because “it’s survival of the fittest!” The average person interprets this idea, originally thought up by Charles Darwin, as meaning that the very strongest will survive. The problem is that “fitness” has an entirely different meaning in biology. It doesn’t refer to strength, health, or physical fitness at all. Instead, biological “fitness” refers to the ability to pass on your genes, generally by having offspring.
In evolution, the end goal is to pass on your genes to the next generation. That doesn’t necessarily require being the strongest, however. In fact, animals that get into too many fights might become injured or killed. Even if they won most of those fights and were the strongest in their group, death means they won’t be passing on their genes. Those animals would therefore be considered to have low fitness. On the other hand, a somewhat weaker animal that stays out of danger might be able to successfully raise several offspring. That animal would be said to have high fitness. In primates, including humans, being a good parent will often raise fitness more than being strong. From an evolutionary standpoint, being able to lift heavy weights means nothing if you never settle down and raise children.
If you want to learn more about how evolution works, the University of California in Berkeley (among others) have put together great evolution resources: click here.
Photo: Wellcome Images UK