Scientists learn rats have rhythm and like to dance to Lady Gaga

By Mark Waghorn via SWNS

Rats have been shown 'bopping' to Lady Gaga, Queen, Michael Jackson and Maroon 5.

They moved their heads in time to Born This Way, Another One Bites the Dust, Beat It and Sugar - all hits of the pop legends.

It demonstrates that rhythm and harmony is not confined to humans but inborn in other species.

Lead author Professor Hirokazu Takahashi, of the University of Tokyo, said: "To the best of our knowledge, this is the first report on innate beat synchronization in animals that was not achieved through training or musical exposure."

Accurately moving to a musical sound was thought to be a skill unique to humans - until now.

Ten lab rodents were fitted with wireless, miniature accelerometers which could measure the slightest head movements.

The Japanese team also recruited 20 human participants who wore similar but larger versions of the same devices on headphones.

One-minute excerpts from five musical pieces - which also included Mozart's Sonata for Two Pianos in D Major, K. 448 - were played at four different tempos.

This was 25 percent slower, the same, twice and four times as fast as the original speed.

For instance, K. 448 is 132 bpm (beats per minute). Results showed the rats' beat synchronicity was clearest within the 120-140 range.

The team also found both rats and humans jerked their heads to the beat in a similar rhythm - with levels reducing the more the music was sped up.

Takahashi said: "Rats displayed innate - that is, without any training or prior exposure to music - beat synchronization most distinctly within 120-140 bpm - to which humans also exhibit the clearest beat synchronization.

"The auditory cortex, the region of our brain that processes sound, was also tuned to 120-140 bpm, which we were able to explain using our mathematical model of brain adaptation."

The optimal nodding tempo was found to depend on the time constant in the brain - the speed at which it can respond to something - which is similar across all species.

This means the ability of auditory and motor systems to interact and move to music may be widespread in animals.

The findings in the journal Science Advances shed fresh light on the workings of their mind - and the origins of music and dance.

Whether you are a good mover or have two left feet depends on your genes. Animals can also react to hearing noise, make rhythmic sounds or be trained to respond to music.

But this isn't the same as the complex neural and motor processes that work together to enable us to naturally recognize the beat in a song, respond to it or even predict it.

Evidence is growing some animals seem to share our urge to move to the groove. It comes from research studies - and home videos.

Takahashi said: "Music exerts a strong appeal to the brain and has profound effects on emotion and cognition. To utilize music effectively, we need to reveal the neural mechanism underlying this empirical fact.

"I am also a specialist of electrophysiology, which is concerned with electrical activity in the brain, and have been studying the auditory cortex of rats for many years.

"After conducting our research with 20 human participants and 10 rats, our results suggest the optimal tempo for beat synchronization depends on the time constant in the brain.

"This demonstrates the animal brain can be useful in elucidating the perceptual mechanisms of music.

"We also hypothesized short-term adaptation in the brain was involved in beat tuning in the auditory cortex.

"We were able to explain this by fitting our neural activity data to a mathematical model of the adaptation.

"Furthermore, our adaptation model showed in response to random click sequences, the highest beat prediction performance occurred when the mean interstimulus interval, the time between the end of one stimulus and the start of another, was around one-thousandth of a second.

"This matched the statistics of inter-note intervals in classical music, suggesting the adaptation property in the brain underlies the perception and creation of music."

The researchers also see the experiments as helping us understand the creation of music itself.

Added Takahashi: "Next, I would like to reveal how other musical properties such as melody and harmony relate to the dynamics of the brain.

"I am also interested in how, why and what mechanisms of the brain create human cultural fields such as fine art, music, science, technology and religion.

"I believe this question is the key to knowing how the brain works. It could lead to developing the next-generation AI (artificial intelligence). Also, as an engineer, I am interested in the use of music for a happy life."