The Reasons Behind That Pleasant Fresh-Cut Grass Smell Aren't So Pleasant
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Mmmm, the smell of freshly cut grass. Like gasoline, cut grass is one of those odd, pungent smells that grows on people, probably because it's linked to warm weather and, hopefully, happy memories of being outside. But it turns out, the cause of the smell isn't nearly as pleasant. The scent is actually a sign of the plant in distress, and it's the side effect of some serious chemical reactions.
International Flavors & Fragrances Is At The Center Of Thousands Of Products
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You've probably never heard of International Flavors & Fragrances. But what if we told you that you come in contact with this company's stuff every day? International Flavors & Fragrances (IFF) is a massive, global, multibillion-dollar corporation that is singlehandedly responsible for providing the scents and flavors for thousands of products. Annually, the company imbues more than 38,000 products with their signature smells and tastes. Chances are, the scent of the clean laundry on your body right now was probably manufactured in an IFF lab. But the jobs of IFF employees goes way beyond making sure you smell good.
The Smell Of Its Owner Can Ease A Dog's Separation Anxiety
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This topic is brought to you by Rover.com, the nation's largest network of pet sitters and dog walkers. Rover instantly connects pet owners with trusted neighborhood pet care in cities across the United States. Get $25 off your dog's first booking—click here for the offer. Leaving your dog at home alone can be one of the saddest moments of your day—that is, assuming you don't later come home to see that Fido's separation anxiety has made him destroy the couch. According to the ASPCA, one way to ease mild separation anxiety in your pet is through something called counterconditioning. Counterconditioning teaches a dog to develop an association between being alone and something good, like getting a treat or a toy. Or, if fMRI brain scans are any indication, something that smells like you.
Stress Makes Things Stink
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When you're stressed, it can feel like everything is terrible. According to a 2013 study in the Journal of Neuroscience, that includes smells. Psychology researchers at the University of Wisconsin-Madison put 14 people into fMRI brain scans, then showed them disturbing images and asked them to smell a series of scents they had previous rated as neutral. Sure enough, being under stress made them more likely to rate those innocuous smells as distasteful.
Smells Trigger Vivid Memories Because Of How Your Brain Is Wired
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You might have noticed that the smell of grass and rubber cleats can bring back the memory of childhood soccer games in starker detail than watching an old movie of a game your parents filmed. Smells have a stronger link to memory and emotion than any of the other senses, and neuroscience may know the reason why. When you see, hear, touch, or taste something, that sensory information first heads to the thalamus, which acts as your brain's relay station. The thalamus then sends that information to the relevant brain areas including the hippocampus, a seahorse-shaped structure responsible for memory, and the amygdala, an almond-shaped area next to the hippocampus that does the emotional processing. But with smells, it's different. Scents bypass the thalamus and go straight to the brain's smell center, known as the olfactory bulb. The olfactory bulb is directly connected to the amygdala and hippocampus, which might explain why the smell of something can so immediately trigger a detailed memory or even intense emotion. But why, if we're such visual creatures, does smell get this elevated status in our brains? Some think it goes back to the way we evolved: smell is one of the most rudimentary senses, with roots in the way single-celled organisms interact with the chemicals around them, so it has the longest evolutionary history. This also might explain why we have at least 1,000 different types of smell receptors but only four types of light sensors and around four types of receptors for touch. We've collected some awesome videos on this topic. Watch them now to learn more.
Key Facts to Know
Memories linked to smells are often stronger and more vivid than those linked to sights or sounds. 0:43
Other senses are routed through the thalamus, which sends them to the necessary processing centers. Smells go directly to an area linked to the memory centers of your brain. 1:19
A 2013 study found that smells are more strongly connected to emotional processing centers than verbal cues are. 1:54