LONDON, Aug. 8 (UPI) -- Our brains, so good at telling us where our bodies are on the solid Earth, don't do so well when it comes to altitude, British researchers say.

In terms of how high up we are, the brain's internal "map" of space is surprisingly flat, scientists at University College London found.

In animal studies, researchers looked at two kinds of brain cells known to create the brain's representation of space; grid cells, which measure distance, and place cells, which indicate location.

As animals in the study climbed upward, only place cells were sensitive to the animal's increasing elevation, and even then only weakly so, a UCL release said Sunday.

"The implication is that our internal sense of space is actually rather flat -- we are very sensitive to where we are in horizontal space but only vaguely aware of how high we are," study leader Kate Jeffery said.

"This finding is surprising and it has implications for situations in which people have to move freely in all three dimensions -- divers, pilots and astronauts for example," she said.

"It looks like the brain's knowledge of height in space is not as detailed as its information about horizontal distance, which is very specific," Jeffery said. "It's perhaps akin to knowing that you are 'very high' versus 'a little bit high' rather than knowing exact height."

The study has been published in the journal Nature Neuroscience.