Humans prick their ears up like animals, say scientists

THE cry of “prick your ears up” is a familiar sound to daydreaming children but, until now, no one believed humans really could move their ears like a dog or a cat.

However, scientists have found that we may have more in common with our household pets than we thought.

Researchers from the Systems Neuroscience & Neurotechnology Unit in Germany have found, for the first time, that humans make minute, unconscious ear movements to direct them towards the sound we want to focus our attention on.

The study, published in the journal elife, measured electrical signals in the muscles of the vestigial motor system in the human ear. Despite the function to move the outer part of our ears having evolved out of human ancestors millions of years ago, the brain still sends signals to the ears to try to “prick” them up when a sound is interesting enough.

Prof Daniel Strauss, the neuroscientist who led the research, said: “The electrical activity of the ear muscles indicates the direction in which the subject is focusing their auditory attention.

“It is very likely that humans still possess a rudimentary orientation system that tries to control the movement of the pinna (the visible outer part of the ear).

“Despite becoming vestigial about 25million years ago, this system still exists as a ‘neural fossil’ within our brains,” he added.

Researchers used sensors attached to the subject’s skin to detect the electrical activity of the muscles responsible for moving the pinna. Subjects then had two types of attention tested. First, the automatic reaction when we hear unexpected sounds, then the goal-oriented attention, which also caused the subjects’ ears to “prick”.

Prof Strauss said the research findings could help with the development of better hearing aids in future.