The idea that standing on your head helps you think may be more than just a myth.
Scientists believe blood flowing through the brain may affect the way nerves transmit signals to other parts of the body.
If the theory is true, it could be used to treat brain diseases including Alzheimer's, schizophrenia and epilepsy.
Practitioners of Chinese medicine and yoga have long taught that standing on your head can boost memory and sharpen alertness.
It was already known that blood transports oxygen and fuel to brain cells.
But scientists at the Massachusetts Institute of Technology, in the U.S., argue that blood may actually influence nerve function and help to regulate information passing through the brain.
Other studies have shown that changes in blood flow affect the activity of nearby neurons, altering how they transmit signals to each other. The theory is borne out by brain scan studies of the sensory homunculus — the brain's detailed map of body parts such as fingers, toes, arms and legs.
When more blood flows to an area of the brain corresponding to the fingertip, for example, people appear to feel a light tap on their finger.
Dr Christopher Moore, from MIT's McGovern Institute for Brain Research, said: "Many lines of evidence suggest that blood does something more interesting than just delivering supplies. If it does modulate how neurons relay signals, that changes how we think the brain works."
Source - Daily Mail