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The origin of dizziness in the human brain, playing an important part in subconsciously recognizing which way is straight up and down and determining when we see funny, has been discovered by Johns Hopkins Medicine researchers.

"Disabling dizziness can be a symptom of damage to the inner ear or other senses such as vision. But in many cases, the problem instead appears to stem from a disruption of the processes in the brain that translate input coming from the inner ears about the pull of gravity and the eyes about our visual sensations into what is known as upright perception," said Hopkins.

For the research, the John Hopkins team gathered eight healthy people and placed them in a dark room, showing them lines that lit up on a screen. The subjects were to address the orientation of the lines by using a dial turned to the right, left or straight.

"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 lead researcher Amir Kheradmand, M.D., a neurology instructor at the Johns Hopkins University School of Medicine in a news release.

Afterwards the subjects received TMS (trans-cranial magnetic stimulation), electromagnetic currents to the right parietal cortex, a part of the brain which is linked to becoming damaged resulting in stroke and balancing problems. The right parietal cortex is also associated with upright perception.

600 electromagnetic pulses were transmitted to each subject for 40 seconds. After the 40-second sessions, the subjects were again asked to show researchers which way each illuminated line on the screen was oriented, according to the study. 

Each person that participated reported that their sense of being upright was altered exactly the same after TMS in the location of the parietal cortex.

"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," said Kheradmand. 

The findings are published in the Oxford Journals Cerebral Cortex.