Posted by: Prospector PJ21 AUG 2013
A recent study goes some way to explaining the origins of a fear of heights (acrophobia), which is apparently neither innate nor due to experience of falling.
Infants do not become wary of heights until about six weeks after they learn to crawl. A study recently reported in New Scientist found that this change is due to developments in visual proprioception — in other words, the optically based perception of self-movement.
Researchers put babies who were unable to crawl into go-carts that they could control with joysticks. After three weeks of training, the babies were lowered towards a 1.3m drop-off.
The heart rates of the go-carters rose by five beats per minute, suggesting they were anxious, while those of non-driving babies remained the same.
The findings suggest that the act of propelling oneself around in space teaches the brain to become aware of information in the peripheral visual field and use it to correct balance. This may explain why looking out of a passenger plane window does not induce vertigo but being in a “bubble cockpit” helicopter can be terrifying.
When looking through a plane window, information in the peripheral vision is relatively fixed. But for the helicopter passenger, who has to make lots of minute bodily adjustments, a dizzying sensation is created.
Other research has shown that virtual reality treatments may help adult sufferers, but one small study also found that cortisol administration could enhance the result of these treatments.
Patients in the study, published in the US Proceedings of the National Academy of Science, were given either cortisol 20mg or placebo an hour before treatment sessions. Patients who received cortisol showed significantly greater reduction in anxiety during phobic situations after the treatment than those who had received placebo.