Why are certain songs and melodies 'hooked' on us?
Songs that we have to listen to again and again , melodies that we are humming mentally throughout the day, songs that we sing in a low voice whenever we have the chance ... if there is a characteristic that defines the potential that music has in our lives is that it hooks us, it hits us without any type of commiseration.
It happens, of course, with many simple and catchy melodies, but even the fruits of the greatest technical virtuosity and the most complex musical pieces are capable of making us think of them all the time. Simply, there are melodies that are practically tattooed in our brain. Why does this happen?
When the music is left it does not leave our head
Some experts they refer to the phenomenon of catchy music as a product of the activity of "earworms", or ear worms . The image of parasites making their nests in our brain and leaving their eggs there is quite unpleasant, but fortunately it is only a metaphor. The idea is that music enters our nervous system through the ears and once there modifies the way in which our neurons communicate with each other creating a dynamic similar to a loop.
In this way, it is enough that at a specific moment an external stimulus enters our brain (in this case, a melody) so that its effects are perpetuated over time, leaving behind a clear trace: our propensity to reproduce that stimulus again and again, converted into a memory .
How does this happen? The science behind the catchy melodies
A few years ago, Dartmouth College researchers shed some light on the mystery of how our brain can simulate over and over again the entry of melody into our nervous system when our ears have already stopped recording this type of stimulus.
An experiment to recognize what happens in the brain
To do this, they conducted an experiment: have a series of volunteers listen to music while their brain is scanned in real time to see which areas of this are activated more than others in each moment.
With this objective, the participants were first asked to choose a series of songs that are familiar to them and others that they have never heard, so that each person could listen to a personalized music list. Once the volunteers had started listening to the music, the researchers included a surprise that had not been explained before: in some moments, the music stopped playing for three or four seconds.
In this way, the researchers they could verify that the part of the brain responsible for processing information related to music is the so-called auditory cortex , and that this continues to be active during those moments in which the music ceases whenever it is familiar, while its activity is interrupted when what stops sounding is unknown music. In other words, when the music sounds to us, our brain is responsible for filling in the blanks automatically, without having to endeavor to do so.
A musical echo that we can not stop
What does the above say about this music that we can not get out of our heads? In the first place, it tells us that the mental processes that we associate with the perception of sensory stimuli can go in the opposite direction to the typical one. That is, it can occur from the brain in general to areas of the nervous system specialized in the processing of sound patterns, since it has been proven that our brain can "continue to sing on its own."
Second, this shows that external stimuli can leave a trace in our brain that, although at first we can ignore, they remain dormant and can cause us to enter a loop, in the same way that removing water with a stick can create eddies that remain even when we are not touching the water.
Neurons that press the "play" automatically
If our brain is responsible for reproducing the way in which our neurons of the auditory cortex were activated when we were listening to the music that entered our ears, we will also be able to create the chain reaction that derives from this activation pattern of several neurons coordinating with each other to process the music ... which means that the necessary ingredients are mixed again so that in the future the loop will appear again.
In order to know why the loop originates, it will be necessary to continue investigating, but most likely it has to do with the way in which certain stimuli create chemical bonds (more or less permanent) between neurons.