Primates too can move in unison

Jan 28, 2013

Japanese researchers show for the first time that primates modify their body movements to be in tune with others, just like humans do. Humans unconsciously modify their movements to be in synchrony with their peers. For example, we adapt our pace to walk in step or clap in unison at the end of a concert. This phenomenon is thought to reflect bonding and facilitate human interaction. Researchers from the RIKEN Brain Science Institute report today that pairs of macaque monkeys also spontaneously coordinate their movements to reach synchrony.

This research opens the door to much-needed neurophysiological studies of spontaneous synchronization in monkeys, which could shed light into human behavioral dysfunctions such as those observed in patients with , echopraxia and echolalia – where patients uncontrollably imitate others.

In the research, published today in the journal Scientific Reports, the team led by Naotaka Fujii developed an experimental set-up to test whether pairs of Japanese synchronize a simple push-button movement.

Before the experiment, the monkeys were trained to push a button with one hand. In a first experiment the monkeys were paired and placed facing each other and the timing of their push-button movements was recorded. The same experiment was repeated but this time each monkey was shown videos of another monkey pushing a button at varying speeds. And in a last experiment the macaques were not allowed to either see or hear their video-partner.

The results show that the monkeys modified their movements – increased or decreased the speed of their push-button movement - to be in with their partner, both when the partner was real and on video. The speed of the button pressing movement changed to be in harmonic or sub-harmonic synchrony with the partners' speed. However, different pairs of monkeys synchronized differently and reached different speeds, and the monkeys synchronized their movements the most when they could both see and hear their partner.

The researchers note that this behavior cannot have been learnt by the monkeys during the experiment, as previous research has shown that it is extremely difficult for monkeys to learn intentional synchronization.

They add: "The reasons why the monkeys showed behavioral synchronization are not clear. It may be a vital aspect of other socially adaptive behavior, important for survival in the wild."

Explore further: Male monkey filmed caring for dying mate (w/ Video)

More information: Yasuo Nagasaka, Zenas C. Chao, Naomi Hasegawa, Tomonori Notoya, and Naotaka Fujii "Spontaneous synchronization of arm motion between Japanese macaques." Scientific Reports, 2013 DOI: 10.1038/srep01151

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Squirrel
not rated yet Jan 28, 2013
The above doi link offers an open access pdf as does http://www.nature...151.html

More news stories

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.