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Whether you like to admit it or not, it's difficult to resist tapping your foot to a solid bassline such as Led Zeppelin's Whole Lotta Love - and now researchers have discovered why.

Psychologists from Canada tracked brain activity of volunteers as they listened to piano tones of different pitches.

The study found that our ears have developed to easily identify changes in lower tones, and this skill develops at a young age.

To find out why lower tones dominate musical rhythms, researchers at the McMaster University in Canada asked 35 volunteers to listen to different pitch piano tones. When the lower tone occurred 50 milliseconds too early, the brain recognised it faster than when the higher tone was mistimed (stock image pictured)

To test their theory, researchers at the McMaster University in Canada asked 35 volunteers to listen to two simultaneous streams of computer-synthesized piano tones, each of a different pitch.

A tenth of the time, the lower tone occurred 50 milliseconds too early; another tenth of a time, the higher tone occurred 50 milliseconds too early.

Psychologist Laurel Trainor and her colleagues used electroencephalography (EEG) sensors placed on the scalp to track the brain signals of the volunteers as they listened to these tracks.

They were looking to see activity that proved when the volunteer had noticed the tones had dropped too soon.

This detection is typically depicted as a spike of electrical activity, known as a mismatch negativity (MMN).

MMN is produced by the brain's auditory cortex from between 120 and 250 milliseconds after an unexpected sound reachee the ear.

This reaction is typically used to sense when the brain detects something is out of place, for example.

Researchers used EEG sensors, (pictured on McMaster University student Kristin Tonus) to track brain signals of the volunteers. They were looking for spikes of activity when the tones were mistimed, and this typically occurs 120 to 250 milliseconds after the deviant sound reaches the ear

The researchers discovered that the MMN signals were consistently larger when the lower note was mistimed, compared to the higher notes.

They also measured the participants' ability to adjust their finger-tapping to the variable timings to discover this was more accurate for the lower notes.

During a second experiment, the research team used a computer model to study how the ear responds to test sounds.

They found that the signal from the auditory nerve connected to the cochlea, part of the inner ear involved with hearing, was also better at detecting timings of low-pitched notes. 

The researchers discovered that the signals were consistently larger when the lower note was mistimed, compared to the higher notes (pictured). They also measured the participants' ability to adjust their finger-tapping to the variable timings to discover this was more accurate for the lower notes, too

This suggests that the differences develop at an early stage of cognitive processing, and humans may have evolved to make these distinctions.

Ms Trainor claimed that her findings explain why the music of many cultures use rhythms created by low-pitched instruments, while the melody tends to be taken by higher pitched instruments.

The findings were published in the Proceedings of the National Academy of Sciences.