dizziness -- 12/7/22
Today's selection -- from Eureka! with an introduction by Jim Al-Khalili. Why do children enjoy being dizzy so much more than adults?
"Children obviously enjoy the feeling of dizziness -- just look at how roundabouts in parks and playgrounds are packed with youngsters. They need that stimulation to develop a healthy balance system, which is necessary to crawl, walk and keep their bodies upright, even on a rocking boat.
"Our balance system is controlled by three senses cooperating in complex harmony. The vestibular system in our inner ear informs us about the position of our head; our eyes tell us how our body is located in relation to the external world; and proprioceptors -- receptors in muscles and joints -- help us to figure out how our body is positioned in space, which is particularly helpful if we cannot see. These elements mature at different rates.
"The vestibular system is fully operational by the time a child has reached 6 months of age; proprioceptors need three or four years more. The development of the visual element is complete by around 16 years of age.
"The sensation of dizziness and nausea following a spinning movement is similar to motion sickness -- a result of the conflicting information our brain receives from the three elements mentioned above. When our body is rotating at speed our vestibular system and proprioceptors can feel it, but our eyes can't locate the horizon. Our brain is desperately trying to resolve this conflict and, because humans are primarily visual, it assumes that the other senses are hallucinating, probably because of intoxication. So the brain tries to get rid of the assumed poison by provoking vomiting."