Blind People Envision the Future Differently Than Sighted People

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iStock

Whether you believe that time marches forward, or that you can put the past behind you, is influenced by your visual development, recent research spotted by BPS Research Digest finds. Published in the Journal of Experimental Psychology: General, the small study found that blind research participants did not conceive of the past as being behind them and the future in front, as most sighted participants did.

To test this phenomenon, Italian researchers recruited 17 blind people, all of whom had lost their sight before their second birthday and had no visual memories, and 17 sighted people (who wore blindfolds) to take part in the experiment. Each had to categorize words that referred to the past or the future by pressing keys on a computer keyboard. In one test, they had to press the key in the forward position whenever they heard a word related to the future, and the key behind their resting position if it related to the past. In the second test, the two were reversed, so the forward key represented the past and the one behind represented the future.

In the final phase, participants had to answer a questionnaire regarding events in their past and future—between one day and three years in each direction—and how close they perceived those events to be.

The results showed that sighted volunteers had an easier time with the key-pressing task if the future was linked to the forward direction and the past linked to the backward direction, but blind volunteers had no implicit association of the future happening ahead of them and the past behind. And in the questionnaire, sighted people perceived the future as being closer than the past, while the blind people perceived them as equally distant.

The study suggests that our concept of time as related to the body's movement in space depends on how our vision develops. It also shows the importance of using a diverse sample in psychology studies. Studies on the psychological links between time and space that don’t test any blind volunteers would suggest that everyone associates the future with forward movement, when, in fact, a significant portion of the world population may not.

[h/t BPS Research Digest]

12 Facts About the Sense of Taste

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iStock/m-imagephotography

A lot more than your tongue is involved in the process of tasting food. Taste is not only one of the most pleasurable of the five senses, but a surprisingly complex sense that science is beginning to understand—and manipulate. Here are 12 fascinating facts about your ability to taste.

1. Everyone has a different number of taste buds.

We all have several thousand taste buds in our mouths, but the number varies from person to person. The average range is between 2000 and 10,000. And taste buds are not limited to your tongue; They can be found in the roof and walls of your mouth, throat, and esophagus. As you age, your taste buds become less sensitive, which experts believe may be why foods that you don’t like as a child become palatable to you as an adult.

2. You taste with your brain.

The moment you bite into a slice of pie, your mouth seems full of flavor. But most of that taste sensation is happening in your brain. More accurately, cranial nerves and taste bud receptors in your mouth send molecules of your food to olfactory nerve endings in the roof of your nose. The molecules bind to these nerve endings, which then signal the olfactory bulb to send smell messages directly to two important cranial nerves, the facial nerve and the glossopharyngeal nerve, which communicate with a part of the brain known as the gustatory cortex.

As taste and nerve messages move further through the brain, they join up with smell messages to give the sensation of flavor, which feels as if it comes from the mouth.

3. You can’t taste well if you can’t smell.

When you smell something through your nostrils, the brain registers these sensations as coming from the nose, while smells perceived through the back of the throat activate parts of the brain associated with signals from the mouth. Since much of taste is odor traveling to olfactory receptors in your brain, it makes sense that you won’t taste much at all if you can’t smell. If you are unable to smell for reasons that include head colds, smoking cigarettes, side effects of medications, or a broken nose, olfactory receptors may either be too damaged, blocked, or inflamed to send their signals on up to your brain.

4. Eating sweet foods helps form a memory of a meal.

Eating sweet foods causes your brain to remember the meal, according to a 2015 study in the journal Hippocampus, and researchers believe it can actually help you control eating behavior. Neurons in the dorsal hippocampus, the part of the brain central to episodic memory, are activated when you eat sweets. Episodic memory is that kind that helps you recall what you experienced at a particular time and place. "We think that episodic memory can be used to control eating behavior," said study co-author Marise Parent, of the Neuroscience Institute at Georgia State. "We make decisions like 'I probably won't eat now. I had a big breakfast.' We make decisions based on our memory of what and when we ate."

5. Scientists can turn tastes on and off by manipulating brain cells.

Dedicated taste receptors in the brain have been found for each of the five basic tastes: sweet, sour, salty, bitter, and umami (savory). In 2015, scientists outlined in the journal Nature how they were able to turn specific tastes on or off in mice, without introducing food, by stimulating and silencing neurons in the brains. For instance, when they stimulated neurons associated with “bitter,” mice made puckering expressions, and could still taste sweet, and vice versa.

6. You can tweak your taste buds.

Most of us have had the experience of drinking perfectly good orange juice after brushing our teeth, only to have it taste more like unsweetened lemon juice. Taste buds, it turns out, are sensitive enough that certain compounds in foods and medicines can alter our ability to perceive one of the five common tastes. The foaming agent sodium lauryl/laureth sulfate in most toothpaste seems to temporarily suppress sweetness receptors. This isn't so unusual. A compound called cynarin in artichokes temporarily blocks your sweet receptors. Then, when you drink water, the cynarin is washed away, making your sweet receptors “wake up” so the water tastes sweet. A compound called miraculin, found in the herb Gymnema sylvestre, toys with your sweet receptors in a similar way.

7. The smell of ham can make your food “taste” saltier.

There’s an entire industry that concocts the tastes of the food you buy at the grocery store. Working with phenomena known as phantom aromas or aroma-taste interactions, scientists found that people associate “ham” with salt. So simply adding a subtle ham-like scent or flavor to a food can make your brain perceive it as saltier than it actually is. The same concept applies to the scent of vanilla, which people perceive as sweet.

8. Your taste buds prefer savory when you fly.

A study by Cornell University food scientists found that loud, noisy environments, such as when you’re traveling on an airplane, compromise your sense of taste. The study found that people traveling on airplanes had suppressed sweet receptors and enhanced umami receptors. The German airline Lufthansa confirmed that on flights, passengers ordered nearly as much tomato juice as beer. The study opens the door to new questions about how taste is influenced by more than our own internal circuitry, including our interactions with our environments.

9. Picky eaters may be “supertasters.”

If you’re a picky eater, you may have a new excuse for your extreme dislike of eggplant or sensitivity to the slightest hint of onion. You might be a supertaster—one of 25 percent of people who have extra papillae in your tongue. That means you have a greater number of taste buds, and thus more specific taste receptors.

10. Some of your taste preferences are genetic.

While genetics may not fully explain your love of the KFC Double Down or lobster ice cream, there may be code written into your DNA that accounts for your preference for sweet foods or your aversion to certain flavors. The first discovery of a genetic underpinning to taste came in 1931, when chemist Arthur Fox was working with powdered PTC (phenylthiocarbamide), and some of the compound blew into the air. One colleague found it to have a bitter taste, while Fox did not perceive that. They conducted an experiment among friends and family and found wide variation in how (and whether) people perceived the flavor of the PTC to be bitter or tasteless. Geneticists later discovered that the perception of PTC flavor (similar to naturally occurring compounds) is based in a single gene, TAS2R38, that codes for a taste receptor on the tongue. In a 2005 study, researchers at the Monell Chemical Senses Center found that the version of this gene also predicted a child's preference for sweet foods.

11. Your genes influence whether you think cilantro tastes like soap.

There may be no flavor more hotly debated or deeply loathed than the herb cilantro (also known as coriander). Entire websites, like IHateCilantro.com, complain about its “soapy” or “perfumy” flavor, while those who like it simply think it gives a nice kick to their salsa. Researchers at the consumer genetics company 23andMe identified two common genetic variants linked to people's “soap” perceptions. A follow-up study in a separate subset of customers confirmed the associations. The most compelling variant can be found within a cluster of olfactory receptor genes, which influence our sense of smell. One of those genes, OR6A2, encodes a receptor that is highly sensitive to aldehyde chemicals, which cilantro contains.

12. Sugar cravings have a biological basis.

Your urge for more hot fudge may have little to do with a lack of self-control. Scientists think that our yearning for sweets is a biological preference that may have been designed to ensure our survival. The liking for sweet tastes in our ancient evolution may have ensured the acceptance of sweet-tasting foods, such as breast milk and vitamin-rich fruits. Moreover, recent research suggests that we crave sweets for their pain-reducing properties.

Yes, You Have Too Many Tabs Open on Your Computer—and Your Brain is Probably to Blame

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iStock.com/baona

If you’re anything like me, you likely have dozens of tabs open at this very moment. Whether it’s news stories you mean to read later, podcast episodes you want to listen to when you have a chance, or just various email and social media accounts, your browser is probably cluttered with numerous, often unnecessary tabs—and your computer is working slower as a result. So, why do we leave so many tabs open? Metro recently provided some answers to this question, which we spotted via Travel + Leisure.

The key phrase to know, according to the Metro's Ellen Scott, is “task switching,” which is what our brains are really doing when we think we're multitasking. Research has found that humans can't really efficiently multitask at all—instead, our brains hop rapidly from one task to another, losing concentration every time we shift our attention. Opening a million tabs, it turns out, is often just a digital form of task switching.

It isn't just about feeling like we're getting things done. Keeping various tabs open also works as a protection against boredom, according to Metro. Having dozens of tabs open allows us to pretend we’re always doing something, or at least that we always have something available to do.

A screenshot of many tabs in a browser screen
This is too many tabs.
Screenshot, Shaunacy Ferro

It may also be driven by a fear of missing information—a kind of “Internet FOMO,” as Travel + Leisure explains it. We fear that we might miss an important update if we close out of our social media feed or email account or that news article, so we just never close anything.

But this can lead to information overload. Even when you think you're only focused on whatever you're doing in a single window, seeing all those open tabs in the corner of your eye takes up mental energy, distracting you from the task at hand. Based on studies of multitasking, this tendency to keep an overwhelming number of tabs open may actually be altering your brain. Some studies have found that "heavy media multitaskers"—like tab power users—may perform worse on various cognitive tests than people who don't try to consume media at such a frenzied pace.

More simply, it just might not be worth the bandwidth. Just like your brain, your browser and your computer can only handle so much information at a time. To optimize your browser's performance, Lifehacker suggests keeping only nine tabs open—at most—at one time. With nine or fewer tabs, you're able to see everything that's open at a glance, and you can use keyboard shortcuts to navigate between them. (On a Mac, you can press Command + No. 1 through No. 9 to switch between tabs; on a PC, it's Control + the number.)

Nine open tabs on a desktop browser
With nine or fewer tabs open, you can actually tell what each page is.
Screenshot, Shaunacy Ferro

That said, there are, obviously, situations in which one might need many tabs open at one time. Daria Kuss, a senior lecturer specializing in cyberpsychology at Nottingham Trent University, tells Metro that “there are two opposing reasons we keep loads of tabs open: to be efficient and ‘create a multi-source and multi-topic context for the task at hand.’” Right now, for example, I have six tabs open to refer to for the purposes of writing this story. Sometimes, there's just no avoiding tabs.

In the end, it's all about accepting our (and our computers') limitations. When in doubt, there’s no shame in shutting down those windows. If you really want to get back to them, they're all saved in your browser history. If you're a relentless tab-opener, there are also browser extensions like OneTab, which collapses all of your open tabs into a single window of links for you to return to later.

[h/t Travel + Leisure]

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