Love exists in vastly different societies around the world. It occupies our mind and drives us to create art, write stories, and even commit acts of violence. Religion, values, and other cultural factors influence who we select as a partner. During a talk at the Secret Science Club, a science lecture series held at the Bell House in Brooklyn, Helen Fisher, Ph.D., asked “Are we naturally drawn to some people for biological as well as cultural reasons?”
From who we marry to how we invest to the words we type, some of our most important decisions are based on how we process instantaneous feedback.
Daphna Shohamy, Ph.D., an assistant professor of psychology and founder and director of The Learning Lab at the Columbia University Mind Brain Behavior Initiative, focused on how the brain supports learning, memory, and decision-making in a lecture hosted by the initiative and sponsored by the Dana Foundation.
Shohamy began by showing two images side-by-side, one freezing terrain and the other, a sun-filled beach. She explained that at age 10, her family moved from Minneapolis to Tel Aviv, and the images depicted both environments. The stark differences between the cultures and her surroundings led her to wonder about the way we learn, and sent her on an academic path that would begin at Tel-Aviv University and include graduate work at Rutgers and Stanford universities before moving to Columbia University five years ago.
Play is a “fairly universal biological impulse,” explained Wang, a professor of molecular biology at Princeton University. It’s a kind of memory that is passed along biologically through generations, which prompts young animals (including humans) to practice skills and scenarios they may face in life.
A Komodo dragon playing tug-of-war with its handler. Kind of like a dog, but in slow motion.
Of course play is not only a learning tool—play is fun! As Wang explained, play activates certain systems in the brain, including the substantia nigra, which through the release of dopamine leads people to experience feelings of reward.
I wouldn’t normally associate chocolate with the self-denying Buddhist culture of the Himalayas. But last night at the Rubin Museum, the center for Himalayan art in New York City, the pleasure of chocolate reigned.
As famed pastry chef Jacques Torres said, “I’m not going to give up chocolate. I never will reach enlightenment.”
The Compass of Pleasure, the penultimate event in the Rubin’s fourth-annual Brainwave series, paired Torres with David Linden, professor of neuroscience at The Johns Hopkins University School of Medicine and author of a new book sharing the event’s title.
Torres, a native of France, began the evening by describing his introduction to Hershey bars. He found the flavor surprising, and not in a good way—it tasted like something was wrong with the chocolate. “If you grow up with it, you will love it,” he said. But it was not like the chocolate he ate growing up in Europe.
This cultural difference speaks to the biology of food preferences. As Linden explained, studies of identical twins raised separately find that even with divergent backgrounds, the twins’ senses of humor and the personalities of their significant others tend to be similar. Food preferences, however, vary widely—there is little genetic basis for what we like to eat. Experience—especially our earliest experiences—determines our food preferences.
Still, people are evolutionarily predisposed to like fatty, salty, and sweet foods. “Culture moves fast, and evolution moves slowly,” said Linden. “Our brain circuits and bodies are not well adapted to unlimited caloric availability…We evolved for a diet that no longer exists,” one that rarely included meats, fats, sweets, and oils. It was evolutionarily advantageous to eat these items at any opportunity, as food might not be available later.
So why is chocolate such a draw for so many people? Chocolate, sex, drugs, gambling, and a host of other substances and activities can activate the pleasure circuit of the brain, in the medial forebrain region, and cause a surge of the pleasure-associated neurotransmitter dopamine. This circuit and addictive substances and behaviors are strongly connected—in fact, there is a perfect correlation between substances that activate the circuit and substances of abuse.
But acts of indulgence are not the only things that can activate the pleasure pathway. Exercise, learning, giving to charity, and even fasting and abstinence can stimulate the pleasure circuit in humans. “Utterly arbitrary experiences can bring pleasure,” said Linden. Pleasurable activities are those we want to repeat, and can vary greatly from person to person. No matter what we enjoy, said Linden, “pleasure is the central motivator of our behavior.”
Back to chocolate: Torres had the audience taste two samples of his creations, one a more traditional piece of chocolate from a single source in Africa, the other a piece with a more complex flavor made from Dominican cacao. The second piece was almost spicy, with a citrus-like flavor. Torres said that this chocolate is less widely liked, as people have less exposure to the flavor.
Perhaps, but I’d take that second piece of chocolate over a Hershey bar any day.
– Johanna Goldberg
New Year’s resolutions in mind, I’ve noticed an influx of determined-looking people at my gym. It’s the same routine every year: January and February the place is packed, and then beginning in March the numbers start to wane. What is it about habits that makes it so hard to break bad ones and form new good ones, even when we know it’s in our own best interest?
In a recent Associated Press article, Dr. Nora Volkow, a Dana Alliance member and director of the National Institute on Drug Abuse, explains that we assign more value to an immediate reward (e.g., chocolate cake) than a long-term goal (e.g., weight loss). The pleasure we get from repeatedly eating the cake is transformed over time into a habit because of the chemical dopamine. As writer Lauran Neergard puts it: “A dopamine-rich part of the brain named the striatum memorizes rituals and routines that are linked to getting a particular reward, explains Volkow. Eventually, those environmental cues trigger the striatum to make some behaviors almost automatic.”
Two main ingredients to breaking bad habits are repetition and time. A recently published report by Phillippa Lally and her colleagues at University College London found that the average amount of time to form a new habit is 66 days. The researchers monitored a group of 96 people looking to form new healthy habits, and rated them based on how automatic their chosen behavior felt.
But while 66 days was the average, the range was widespread: from 18 to 254. As PsyBlog points out, “Clearly [the length of time] is going to depend on the type of habit you’re trying to form and how single-minded you are in pursuing your goal.”
The good news is, Lally et al. found that skipping one day did not affect the habit-forming process. But old habits are easy to resume, as reported in a 2005 study led by Dana Alliance member Ann Graybiel at MIT.
In an MIT report, Graybiel said, “We knew that neurons can change their firing patterns when habits are learned, but it is startling to find that these patterns reverse when the habit is lost, only to recur again as soon as something kicks off the habit again.”
So, for all my fellow gym-goers, here are the steps Volkow offered in the AP article to stay on track in the New Year:
- “Repeat, repeat, repeat the new behavior…
- Exercise itself raises dopamine levels, so eventually your brain will get a feel-good hit even if your muscles protest.
- Reward yourself with something you really desire… You exercised all week? Stuck to your diet? Buy a book, a great pair of jeans, or try a fancy restaurant — safer perhaps than a box of cookies because the price inhibits the quantity.
- Stress can reactivate the bad-habit circuitry…
- And cut out the rituals linked to your bad habits. No eating in front of the TV, ever.”
–Ann L. Whitman