Christmas and New Year’s Day are over and it is back to the grind of daily life which, in 2016, is quite a bit different than it was just ten years ago. We spend more and more time looking at screens such as TV and computers. A recent survey found American adults spend 5 ½ hours a day engaged in such activities. Kids spend even more time with their faces glued to a screen.
As technology becomes smaller and more mobile, we add a new and additional element of difficulty in processing the information from the screen. Balance, orientation and visual stability occur as a result of the brain efficiently processing information that is received by the inner ears, the eyes, and the sense of touch. Most of the time, this information all agrees with each other to let you know if you are moving or if you are still. Historically, there have been a few classic situations where this information doesn’t agree, such as sitting in a car watching a train go by, or standing in the middle of a large, moving crowd. In these situations, your eyes sense a lot of movement, but your brain is able to check with your inner ears and sense of touch, and assure you that it is the visual scene that is moving, not you. As long as two of the three senses (eyes, ears, touch) register no movement, the brain will suppress the response to the visual information, and orientation and balance will be maintained.
When one part of the system is compromised, these busy visual scenes can lead to disorientation, feeling dizzy and nausea (keep in mind that nausea is nature’s warning signal that you don’t have enough information to ambulate safely). Basically, the brain makes you feel too sick to want to get up and move around. Compromises to the system could include:
- Chronic inner ear weakness – when the inner ear is injured the brain becomes more reliant of visual information for orientation, which is fine until the visual information is moving also.
- Migraine –the Migraine brain does not resolve these expected conflicts between what the eye sees and what the ear senses. Migrainuers threshold for triggering nausea and disorientation is low compared to the non-Migraine population.
- Neuropathy of the lower extremities –This is a common consequence of diabetes where the nerves in the toes and feet are damaged. Basically, these people don’t feel the floor normally when they are on their feet. The brain naturally and gradually becomes more dependent on the information received from the eyes and inner ear. When the visual information is compromised, they can become dizzy, unsteady and disoriented.
There is a name for this phenomenon called “Supermarket Syndrome” where people are challenged by the flickering neon lights and colorful items on the shelves of a grocery store. A common reaction to this loss of reliable visual information is to want to keep your hands on the shopping cart to increase tactile feedback.
In the past several years, technology has introduced these challenging visual scenes to many more settings, and it is only going to get worse. Stop back next week to continue this topic.
Photo courtesy of Alamy.com