Humans have fast-twitch mimetic muscles which means they can form fast but fleeting facial expressions. These fast-twitch fibres allow for greater facial mobility and enable small but meaningful ...

Our so-called mimetic muscles are powered by fast-twitch myosin fibers that tire quickly, which is why we can can't hold them these expressions for very long, a statement explains.

In the study, researchers analyzed the anatomy of tiny muscles used to form facial expressions called mimetic muscles. In humans, these muscles are dominated by "fast-twitch" myosin fibers that ...

In people, mimetic muscles are dominated by "fast-twitch" myosin fibers that both contract and tire quickly. That's why we can make expressions instantly but not maintain them for long, ...

Those puppy eyes indeed came from humans rather than natural selection, according to past research published in the Proceedings of the National Academy of Sciences. “Our initial study located a muscle ...

The study focused on mimetic muscles, a tiny group of fibers that control facial expressions. There are two types of these muscle fibers, fast twitch and slow twitch.