Not everyone can tap out a beat, but new research suggests that everyone has a drummer hiding deep inside the recesses of their nervous systems. According to a new study, scientists studying how humans process information have found evidence that indicates our brains can pick up on rhythmic patterns, even when we’re not paying attention to the music.
In a new study published in the journal Brain and Cognition, researchers from the University of Groningen in the Netherlands sat 20 psychology students in front of a computer and had them complete a task involving pressing the spacebar on a keyboard as fast as they could. But that was just a distraction—the real test had to do with the music the researchers were piping into the room and the response from the students’ eyes.
"The perception of music is a complex interaction between what we hear and our interpretation," the researchers write in the study. "This is reflected in beat perception, in which a listener infers a regular pulse from a musical rhythm."
Throughout the test, the researchers played one of several audio clips that sounded like drum rhythms you might hear in a pop or rock tune. Several of the songs, however, left out particular beats throughout the clip: some were missing a bass note here or there, others were missing hi-hat clicks. Meanwhile, a camera trained on the subject’s eyes recorded the movement of their pupils in order to see how they responded to the missing beats.
Because people can’t consciously control how big their pupils get, studying this movement can help shed light on how we perceive the world. For instance, in this study, the researchers found that even when the subjects were ignoring the music, their pupils would get larger when a beat was dropped. In addition, they found that the subjects’ eyes reacted differently when different beats were missing—a missing bass note played on a beat would provoke a bigger reaction than a missing syncopated hi-hat tap, for example. According to the study, that suggests that people not only have a basic sense of rhythm, but they can distinguish between more important notes on an unconscious level.
“People have very little control over their pupillary response,” Bruno Gingras, a researcher at the University of Innsbruck’s Institute of Psychology, who was not involved with this study, tells Smithsonian.com. “People have used other methods to show that people react if they hear a surprising chord, or a surprising note. But so far it has not really been shown with pupillary dilation.”
In recent years, scientists have begun looking to pupillary movement to glean new insights into the brain. While they have long known that pupil size and movement is an unconscious reaction to stimuli like light and sound, it was only once cameras and software became sensitive enough that researchers were able to start thinking about the eyes as a window into the recesses of our brains.
“Physiologic signals in general are quite noisy,” Gingras’ research partner Manuela Marin, who was also not involved with this study, tells Smithsonian.com. “Even if you have other autonomic nervous system measures, like skin conductance, you need very good technology to show the effects.”
Pupillary movement, on the other hand, is pretty obvious. After all, with a simple camera, researchers can gauge a person’s unconscious reaction to something just by tracking how big their pupils get, even as they perform another task.
While Gingras and Marin say this study presents some intriguing evidence for humans having an innate sense of rhythm, it would be interesting to see how professional musicians would respond to a similar test. They suspect that musical training and knowledge could spark a much stronger reaction to changes in rhythms and musical patterns than a psychology student who may not have spent as much time studying music in the same way. Applying this technique to different groups of people could help paint a more nuanced picture of how deeply ingrained music is in our unconscious minds.
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Also found a exercise program from the web that is 30mins long [click]
Your Brain's Got Rhythm, And Syncs When You Think
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Maggie Starbard/NPR
Even if you can't keep a beat, your brain can. "The brain absolutely has rhythm," says Nathan Urban, a neuroscientist at Carnegie Mellon University in Pittsburgh.
When you concentrate, Urban says, your brain produces rapid, rhythmic electrical impulses called gamma waves. When you relax, it generates much slower alpha waves.
“ Individual brain cells are little clocks. They have an intrinsic frequency.
- Nathan Urban
The internal cadences of the brain and nervous system appear to play an important role in everything from walking to thinking, Urban says. And abnormal rhythms, he says, have been associated with problems including schizophrenia, epilepsy, autism and Parkinson's disease.
The rhythms of the brain begin with the firing patterns of individual brain cells. Some types of cells tend to fire as slowly as once a second, while others tend to fire more than a hundred times as fast. "They're little clocks," Urban says. "They have an intrinsic frequency."
All those different beats in the brain could produce chaos. One reason they don't is that groups of brain cells synchronize when they need to get something done. So, when a mouse is exploring a new place, cells begin firing together in areas of the brain involved in navigation and memory.
Urban has been studying how brain cells achieve this synchrony and has found evidence that it works a bit like a room full of people clapping their hands. At first, each person claps to his own beat. But if you ask them to clap together, they'll start listening to their neighbors and adjusting their rhythms until the claps are synchronized.
Brain cells appear to do something very similar, Urban says. There's still debate about why this synchronization takes place. But many scientists believe it's important, because they know that when any two cells fire together, the connections between them get stronger, a process that is critical to learning and memory. The Rhythms of Digestion and Dance
Of course, rhythms in the brain and nervous system also control many rhythms in the body. Among these rhythms are the repetitive muscle contractions responsible for functions as basic as digestion and as elevated as dance, says Eve Marder, a biology professor at Brandeis University. Marder has spent years studying the complex patterns of nerve cell firing that allow crabs to chew, filter and digest their food.
Dance And The Brain
"It turns out that the stomach of a crab is a very, very complicated mechanical device," driven by the precisely choreographed contractions of 42 sets of muscles, Marder says. And the way a crab processes lunch has a lot in common with the way a ballerina does pliés, she says. Both actions rely on circuits of nerve cells that fire in a sequence, activating one muscle, then another, then another until the pattern repeats.
Rhythmic sequences are also required to move around, says Mark Churchland, a brain scientist at Columbia University. Walking, for example, requires repeatedly lifting a foot up, putting it down, and pushing it back. Fish swish a tail from side to side to swim. "It's sort of hard to imagine any way of doing continuous locomotion that wasn't built on a rhythmic underpinning," Churchland says.
Many of these rhythms are maintained by cells in the nervous system, not the brain, Churchland says. This means the brain can use a kind of shorthand to control motion. So instead of sending instructions for each muscle contraction needed to take a step, the brain sends a general command: "Activate the walking rhythm."
What's interesting, Churchland says, is that the brain may be using this rhythmic shorthand for some motions that don't appear rhythmic at all, like reaching. "You start with your hand in one place and you move your hand to another place. There's nothing rhythmic about that," he says.
But when Churchland took a closer look at reaching he found something really surprising. "That pattern of muscle activity is the sum of two rhythms," he says. When Rhythms Go Wrong
Maggie Starbard/NPR
Diseases including epilepsy, schizophrenia and Parkinson's can disrupt the brain's normal rhythms. People with Parkinson's disease, for example, tend to develop abnormal firing patterns in their brains that result in tremor and other difficulties with movement.
Surprisingly, these symptoms of Parkinson's are greatly reduced when patients respond to the external rhythms of music and dance. This transformation is easy to see at a studio in Silver Spring, Md., where Lucy Bowen McCauley teaches a dance class designed for people with Parkinson's.
Maggie Starbard/NPR
When a half dozen of her students arrive for class, their steps are halting, their gestures visibly distorted by tremors. After some warm-up exercises, they make their way to folding chairs on the dance floor and sit. Then, as the sound of Ella Fitzgerald fills the room and McCauley calls out "heel, heel, heel, toe, toe, toe," the group begins tapping out the beat in unison.
“ You're trying to go forward or sideways or whatever and your feet won't move.
- Phyllis Richman
"When we use music, these Parkinson's patients become dancers," McCauley says. "They look graceful and they can move in rhythm."
After class, some students talk about the role that rhythm plays in their disease. "My doctor says he can tell a Parkinson's tremor from any other kind," says Anne Davis, a retired teacher who's had the disease for more than 15 years. That's because the tremors of Parkinson's have their own distinctive rhythm, Davis says.
“ When we use music, these Parkinson's patients become dancers. They look graceful and they can move in rhythm.
- Lucy Bowen McCauley
And a man-made rhythm has helped reduce her tremor, she says. It comes from an implanted deep brain stimulation device that sends high-frequency electrical impulses to the area causing her hands to tremble. Scientists think the fast pulses somehow override the much slower rhythm responsible for tremor.
Many Parkinson's patients also experience something called freezing — a temporary inability to initiate a movement like taking a step. "You're trying to go forward or sideways or whatever and your feet won't move," says Phyllis Richman, another student in the dance class and a former food critic for the Washington Post. "So then you fall," Davis adds.
But musical rhythms have a remarkable ability to help Parkinson's patients unfreeze, McCauley says. "Two times I've had people really have trouble walking down the hall to get to the class," she says. The solution: "We hum a tune. One time I did a march and one time I did a waltz. And we got in sync with the rhythm and they were able to get their feet to match."
Of course, dance doesn't halt the brain damage caused by Parkinson's. But McCauley's students say the rhythms of dance give them a respite from the abnormal brain rhythms of Parkinson's. "I come here because this is where I get joy," Davis says.
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