DJ Pug !! Nice music!
Published February 16, 2014
Like cat videos, it's pretty easy to stumble over dancing animal videos online. Are these animals really hearing the music and keeping a beat, or are they merely moving around at someone else's behest?
The question has turned into a burgeoning scientific field—one that looks at everything from boy-band-loving cockatoos to head-bobbing sea lions—with implications for how and why music evolved in people.
Every human culture through time that we know of has evolved some kind of music, says Aniruddh Patel, a cognitive neuroscientist at Tufts University in Medford, Massachusetts, who spoke at a presentation during the ongoing American Association for the Advancement of Science (AAAS) conference.
But how deeply rooted our penchant for music is still eludes researchers. It could be that music is simply an extension of our ability to imitate sounds, while others including Charles Darwin have proposed that a sense of rhythm is common in all animals as a consequence of similar wiring in our nervous systems. (See "Why Did Humans Invent Music?")
It wasn't until 2009 when researchers got their first glimpse into the ability to keep a beat in animals. Patel received a link to a video of Snowball the cockatoo dancing to "Everybody" by the Backstreet Boys.
The researcher contacted Snowball's owner to see if he could run the bird through tests designed to see if the cockatoo was simply following a human dancer off-camera, or if the bird was truly keeping a beat.
It turned out that Snowball could adjust his dance moves when Patel slowed the song down or sped it up. That flexibility is key to determining whether animals can follow a melody like people can, Patel explains.
Since then, scientists have demonstrated that a similar, if less flexible, ability exists in bonobos and chimpanzees. And a captive sea lion at the University of California, Santa Cruz has become quite proficient at bobbing her head in time to "Boogie Wonderland."
National Geographic caught up with Patel at AAAS to talk about the perception of rhythm and music in people and in animals.
How long have people have been looking at the ability of other animals to follow a beat?
In biology, there's been a long interest in synchrony among certain species. It's well known for example that there are certain fireflies that will flash synchronously. And this has been studied since the 70s.
But in terms of animals' sensitivity to musical beats and being able to synchronize to an auditory beat in the way that we do, which is very flexible—being able to slow down and speed up and extracting that beat from music—that's very recent.
The first paper was the paper I published in 2009 [on Snowball]. It's the earliest example of another species having that capacity.
What other animals can do this?
We're talking about sensitivity to an auditory beat and moving to the beat synchronously, but also being able to do it at a broad range of different tempi like a human can. So far only parrots and a sea lion—Peter Cook showed that a sea lion could do this.
There's also video evidence that some elephants can do it. But that's still a little uncertain, I would say. But the parrots are pretty solid and the sea lion work is pretty solid.
What about nonhuman primates?
There is one published study by a researcher in Japan, Yuko Hattori, who should be here speaking today, showing that chimpanzees can synchronize to a metronome at one tempo, near their spontaneous tempo—[which] is the tempo that they like to tap anyway. But they don't show this flexibility where if you slow it down or speed it up, they spontaneously match it.
But it's a young field. Maybe with a little bit more training and experience, [the chimpanzees] will show it.
When do we gain the ability to synchronize to a beat?
We know kids around four or five can do it. Younger kids can do it too, but usually only at one tempo close to their preferred tempo. And then as you grow older you broaden the tempi at which you can do this. But I would say it emerges between three and five.
You mention that there are different parts of our brain involved in our ability to move to a beat. Which ones are they?
So when we just perceive a beat—this is just sensing a beat in music, even when we're not moving—there seems to be a widespread network involving auditory regions [and] the motor planning regions of the brain. Regions that are normally involved in planning movements, which is interesting because you're not moving or even intending to move. But those regions are playing some sort of role in analyzing the rhythmic structure.
Deep brain structures like the basal ganglia, the cerebellum—they're known to be important for timing. Parts of the parietal cortex, which are thought to be important in integrating different brain regions and mapping between them.
And so you see this broad network, which suggests that it's not a simple function of some little brain area. It actually requires a lot of coordination, which is one reason why it might not be that easy for many other species and takes a while to develop [in people] and is related to other aspects of cognition and so forth.
Has anyone looked at what areas of the brain are involved in animals?
Hugo Merchant, the neurobiologist from Mexico is here. He has been studying tapping to a beat in monkeys. He's actually measuring from parts of their brains while they do this. So he is the person to ask about what brain regions [are involved]—in monkeys, anyway. But they don't seem to quite do it the way we do it.
So following a rhythm has been seen in parrots, a sea lion, maybe in elephants, bonobos, and chimps. What does that mean in terms of its adaptive value, or importance in evolution?
The theory that I propose is that somehow, it's a consequence of being able to imitate sound. We can imitate complex sounds unlike any other primate. And that means you have to have special connections between your hearing centers and your movement centers in your brain. I felt that laid the groundwork for this other ability, which is also a connection between hearing and movement.
If that's true, then in a sense, this ability [to follow a rhythm] was a byproduct in evolution. And that's why I tested the theory with the parrot and why I'm so interested in the monkey work.
So far the theory's held up except for the sea lions, which are not known to be vocal learners. But, on the other hand, they're not known not to be either, so it's a little bit up in the air with them.
It may be a byproduct of something else that we do, or, if Darwin's theory is right, it's just a deep aspect of brain function that music builds on.
In terms of its adaptive value, people have speculated that it played some role in social bonding in humans. Moving in synchrony makes people feel connected socially and emotionally.
Is this kind of behavior seen in animals that aren't social?
Well, the insects. Fireflies, they're not really social. The flash, they'll be near each other when they're doing this behavior, but they don't live socially and cooperate when they're foraging or anything like that.
What animals would you like to see tested next?
Horses. Absolutely. I just published a paper with a method for testing horses and whether or not they synchronize to the beat of music. Because, they are definitely not vocally flexible, they're not related to any vocally flexible animals.
One of the ambiguities of the sea lion work is they're related to seals that we know are vocally flexible, whereas horses don't have any vocally flexible near-relatives.
And people will occasionally tell me [horses] spontaneously entrain to the beat of music, and that would really be a conclusive refutation of my hypothesis. So, I would love for somebody to test horses.
This Q&A has been edited and condensed.
Follow Jane J. Lee on Twitter.
Thanks for the reply, by the way I checked and no music is used in dressage exercises. Did Ronan listened only to these 2 tunes? Could she make out the primary beat in other rythms? I am thinking about salsa (that has a very strong secondary beat), or a waltz. Maybe a bigger fish could help...
Marine life get pretty funky too!
I have been disturbed for quite a while now on NG's reporting on web and in magazine of research projects involving animals. While the seal is no doubt adorable, and maybe even well taken care of, it is still being forcibly confined and conditioned by humans, something that in our "enlightened" age should not even continue to occur. I realize the need for full and impartial reporting when covering a story, and that story might include animal testing for research, but I can't help but feel that the impartial reporting on the part of NGM supports those views by not even hinting at a sliver of condemnation.
There are 3 articles published previously that come to mind.
The article "The Secrets of Sleep" published in May 2010, an article which I cannot reference immediately which supplied photos of a pregnant sheep with electrodes running out of her womb and out the vagina, and the recent issue February 2014 in the article "Secrets of the Brain.
In this February's article, we have a photo on page 56 of a rhesus macaque in a bionic suit. While it is described as aiding the monkey to walk, it is not described why the monkey needs a suit to walk. It is obvious that researchers have broken the monkey's back in order for him to be able to test the suit. How many monkeys have they done that to? And, what do they do with them after the testing phase? I don't think they send them to a palliative care hospital. Most likely destroyed then incinerated.
The sheep pictured in the unfound article could not have been comfortable with electrodes pouring out of her and hooked to equipment. It seemed a cruel way to collect data.
And finally, from "The Secrets of Sleep"
In the most famous attempt to figure out why we sleep, in the 1980s, Rechtschaffen forced rats to stay awake in his University of Chicago lab by placing them on a disk suspended on a spindle over a tank of water. If the rats fell asleep, the disk would turn and throw them in the water; when they fell into the water, they immediately woke up. After about two weeks of this strict enforcement of sleeplessness, all the rats were dead. But when Rechtschaffen performed necropsies on the animals, he could not find anything significantly wrong with them. Their organs were not damaged; they appeared to have died from exhaustion—that is, from not sleeping. A follow-up experiment in 2002, with more sophisticated instruments, again failed to find “an unambiguous cause of death” in the rats.
At Stanford University I visited William Dement, the retired dean of sleep studies, a co-discoverer of REM sleep, and co-founder of the Stanford Sleep Medicine Center. I asked him to tell me what he knew, after 50 years of research, about the reason we sleep. “As far as I know,” he answered, “the only reason we need to sleep that is really, really solid is because we get sleepy.”
Wow. Torturing untold numbers of rats to learn absolutely nothing. Anyone who has ever worked with rats (including myself) would testify to their intelligent gentle nature. I can guarantee they were fully aware of the cruelties carried out towards them.
While I love NG and have read faithfully since I was a child, I am dismayed to see support of such horrors within their pages, without at least of mention of it. Many notable researchers of the past have claimed that we have learned almost nothing from vivisection. I think all we have learned is how to harden ourselves against cruelty for perceived gain, or just plain learned how to be more cruel. In the current state of the world, shouldn't we all be reaching to learn how to be more compassionate, loving and kind? Those are the qualities that will ultimately usher in a more enlightened age.
When my lazy quarter horse would slow down, I use to sing a rhythmic song in time with his hoof beats and then speed it up slowly to speed him up without kicking or prodding him on. Worked like a charm.
Horses can be trained to dressage performance. Have the researchers thought of exploring these skills as well?
They are abusing that poor animal with that terrible Backstreet Boys music. The least they could do is play it something decent. (For the record, I think Boogie Wonderland is fine.)
Dancing as a mating ritual for mammals such as us gets the heart pumping and the blood flowing, which heightens the sensation in, among other places, but specifically, our genitals. The desire to dance itself used to be treated by some sects of backward pre-Victorians as naughty. We have luckily moved beyond that but have forgotten the impulse to dance was ever societally restricted, which is why dance as precursor to sexual activity is seen properly as healthy, while the sexual activity it leads to is still societally repressed.
@Anna F. There are certain classes in competition where horse and rider perform to music (ie. Grand Prix Freestyle at the Olympics).
I'm not sure whether the researchers asked Ronan to listen to other songs. I do know that they started her out on a simple metronome beat. Once she got good at that, they tried the Backstreet Boys song in honor of Snowball and the work done with that parrot.
@Anna F. I asked about that. The problem with dressage is that the horse is taking cues from the rider, which makes it hard to determine whether the horse is paying attention to the music or the person on its back. As we discuss near the end of the piece, Dr. Patel would love to study horses next, but those tests would have to be conducted without a rider.
Following along, Craig, Poe, in Masque of the Red Death has his prince trying to keep out the plague while he and his chosen imoralists lived naughty lives within. Among the nasties, they danced the waltz.
@craig hill If true, then chimpanzees and gorillas should be able to keep a beat, at least close to a sexual one. That could be a key, as our ability to keep a beat is also within a narrow range.
@Jane LeeThanks for the reply, by the way I checked and no music is used in dressage exercises. Did Ronan listened only to these 2 tunes? Could she make out the primary beat in other rythms? I am thinking about salsa (that has a very strong secondary beat), or a waltz. Maybe a bigger fish could help...
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