"Our brain has this amazing way of knowing where we are in space, whether we are upright or tilted at an angle, even if it is completely dark and we can't see anything around us," said Amir Kheradmand, M.D., a neurology instructor at the Johns Hopkins University School of Medicine who conducted the research.
 

"This study suggests there's a small area of neural tissue in the parietal cortex substantially involved in this ability, giving us a place to start thinking about how we may be able to treat people with disorienting dizziness."
 

The newly discovered region of the brain may be what causes feelings of spatial disorientation, dizziness, unsteadiness, and "floating" that some people experience. The finding may help open the door to treating such conditions, researchers said.
 

Disabling dizziness can be a symptom of ear damage or vision problems, they noted. But in many cases, the problem stems from a disruption of the processes in the brain that translate input coming from the inner ears about gravity and the eyes about what is upright.

Dr. Kheradmand said his team focused on the right parietal cortex of the brain because studies in stroke victims with balance problems suggested that damage to region was centrally involved in upright perception.
 

For the study, the team recruited eight healthy volunteers, placed them in a dark room, and showed them lines illuminated on a screen. The researchers asked them to report the orientation of the lines by rotating a dial to the right, left or straight.
 

The subjects then received TMS (trans-cranial magnetic stimulation), which painlessly delivers electromagnetic currents to precise locations in the brain that can temporarily disrupt the function of the targeted area. The results showed that the participants' sense of being upright was skewed after receiving TMS in the same spot in the parietal cortex.
 

Dr. Kheradmand said the findings suggest TMS could potentially be used to treat chronic dizziness.
 

"If we can disrupt upright perception in healthy people using TMS, it might also be possible to use TMS to fix dysfunction in the same location in people with dizziness and spatial disorientation," he said.
 

This study was funded, in part, by the National Institutes of Health.