Brain can recognise familiar tune in the blink of an eye - study
By Nina Massey, PA Science Correspondent
Some people can recognise a tune in the blink of an eye, new research suggests.
The human brain can identify a familiar song within 100 to 300 milliseconds, according to a new study.
Scientists say the findings highlight the deep hold favourite songs have on our memory.
Researchers at the University College London (UCL) Ear Institute wanted to find out how fast the brain responded to familiar music.
They also wanted to examine the temporal profile of processes in the brain which allow for this.
Senior author Professor Maria Chait said: "Our results demonstrate that recognition of familiar music happens remarkably quickly.
"These findings point to very fast temporal circuitry and are consistent with the deep hold that highly familiar pieces of music have on our memory."
The small study published in the Scientific Reports journal looked at a main participant group of five men and five women.
They each provided five familiar songs, and for each participant researchers then chose one of the familiar songs and matched this to a tune.
This was similar - in tempo, melody, harmony, vocals and instrumentation - but was known to be unfamiliar to the participant.
Participants then passively listened to 100 snippets less than a second long, of both the familiar and unfamiliar song, in random order.
Around 400 seconds was listened to in total.
Using electro-encephalography (EEG) imaging, which records electrical activity in the brain, and pupillometry - a technique that measures pupil diameter, which is considered a measure of arousal, scientists analysed the responses.
Researchers found the human brain recognised familiar tunes from 100 milliseconds (0.1 of a second) of sound onset, with the average recognition time between 100ms and 300ms.
They say this was revealed by rapid pupil dilation, likely linked to increased arousal associated with the familiar sound, followed by cortical activation related to memory retrieval.
No such differences were found in a control group made up of international students who were unfamiliar with all the songs "familiar" and "unfamiliar".
It takes around 300 milliseconds for the human eye to blink.
Professor Chait added: "Beyond basic science, understanding how the brain recognises familiar tunes is useful for various music-based therapeutic interventions.
"For instance, there is a growing interest in exploiting music to break through to dementia patients for whom memory of music appears well preserved despite an otherwise systemic failure of memory systems.
"Pinpointing the neural pathway and processes which support music identification may provide a clue to understanding the basis of this phenomena."
The researchers acknowledge a number of limitations to the study, including that the familiarity is a multifaceted concept, and that only one familiar song was used per subject.