Imagine when your hand was about to hold a pet cat and suddenly she hissed. Does shock make you speechless?
There is a scientific reason why we often suddenly stop moving when there is movement or sound that appears unexpectedly. According to the researchers, this mechanism needed human to survive.
In a study published in the Journal of Neuroscience, Jan Wessel, an assistant professor in the University of Iowa Psychology Department and his team conducted a small group trial.
Participants are instructed to step on the right pedal when they see the letter W on the right side of the computer screen, and the left foot when the W appears on the left side of the screen. If on the computer screen appears the stop signal in the form of letter M, participants are asked not to make any movements, including stepping on the pedal.
During this game, the researchers turned the bird recordings unexpectedly as the stop signals appeared.
The researchers found that people will more often stop suddenly when hearing unexpected sounds, compared with not hearing a sound at all.
The participants managed to stop the movement up to 80 percent when the signal stopped and the sound of birds appeared together. But when there is no sound of birds at all and there is only a stop signal, the participants can only stop moving 65 percent of the total trial.
“It means that when a signal stops appearing along with an unexpected event (the sound of a bird), people tend to stop,” Wessel said.
“The reason for the behavior is that your mind is telling the body’s motor system, like saying ‘I know you’re doing this, but stop it, fast, right now,'” he added.
To ascertain what is going on in the brain, the researchers then use a cap that measures electrical activity in the brain region. As it turns out, the brain wave activity increases when the sound of the bird accompanied the instructions to stop appearing simultaneously.
This suggests that auditory, visual, or other sensory cues stimulus can accelerate brain communication and the motor system of the body.
The communication between the brain and the motor system is also very strong and occurs instantly so that Wessel and the team argue that this is a survival mechanism that has been rooted in human beings since time immemorial.
“It’s very basic, our brains have evolved to do this, the human brain is adapted to survive, and I think that’s why these systems are connected to each other,” Wessel said.
Now, researchers hope to utilize this mechanism as a new treatment method for patients with motor disorders, such as Parkinson’s, ADHD, and in the elderly who have decreased motor function.