Mia Rozenbaum
Your body adapts to the challenges of the environment. When someone throws something at you, you duck to avoid it. Visual inputs are a big part of body anticipation and adjustments prior to action. Could sounds create the same kind of reflexes? A team of Italian scientists, decided to check out how sounds affect skateboarding. Come catch the ride!
(Flickr / knausphotography)
Humans are able to recognize and discern among different types of events just by listening to the sounds they produce. Many everyday sounds trigger movements: a bowl crashing to the ground, a mosquito buzzing by your ear or even the sound of your phone ringing. Neural imaging studies have shown that the sounds specific to actions, in particular those produced by human gestures, activate motor and pre-motor areas in the brain. It looks like the same populations of neurons are activated when listening to an action and when performing it. Could there really be a mirror neuron system not just for action execution and visual observation, but also for auditory perception?
Evidence already shows that when people trained to play a sequence of notes on the piano then listen to the same music, the motor center in their brain is activated. This strongly suggests a link between sound perception and action planning.
Could playing a sound help us anticipate forthcoming actions? A team of researchers lead by Dr. Paola Cesari, working at the Neurological and Visual Sciences Department at the University of Verona, tried to identify the role of sound in action anticipation and performance when… skateboarding! Study subjects, aged 18 to 75 (yes, grandpa rode that skateboard), with more or less experience in skating were tested on their ability to anticipate and simulate a skateboarding jump just by listening to the sound it produces.
The participants were placed on a simulation skateboard where pressure below each foot and muscle contractions in the legs were recorded while the sound of a skateboard in movement was played. Turns out, only the confirmed skateboarders were capable of anticipating the correct movements linked to the jump sound. Surprisingly (or not), those with no experience in skateboarding, regardless of age, showed a pattern of contraction not reflective of the actions in the recording but rather linked to balance and stability.
However, the most important information relies on the fact that the skaters were capable of anticipating the jump by changing their posture just 200ms after the beginning of the audio cue. They used the sound information to deal with the jump and plan the action. Visually triggered postural adjustments have already been recorded (50 to 300ms after the cue), but this is the first time one based on sound has been observed.
Regardless of their skating experience, the team noticed that the subjects were perfectly capable of recalling the audio “path” (faster, slower, jump) of the skateboard, even if they couldn’t follow the audio action cue. This suggests that there might be two pathways in the brain to process sounds. The first would be linked to sound identification and the second would be for the dynamic action control of movements based on auditory perception and experience.
This study gives us whole new insight on how sound could affect common reflexes and learnt movements. Sounds can help guide and trigger the anticipation of movements almost like vision. We could be facing a whole new dimension of brain activity. Ready to roll with it?
