Our vestibular system allows us to sense the direction of gravity (and so which way is up), as well as horizontal and vertical movement (as in a car or a lift) and in three dimensions (as on a rollercoaster). Research shows that a healthy vestibular system is important not only for balance but for our sense of being grounded inside a physical body; in fact, people with vestibular problems are more likely to report out-of-body experiences. They’re also more likely to get lost, because a healthy vestibular system is important for a good sense of direction.

For all of us, though, the older we get, the duller all our vestibular responses become. This becomes noticeable at a population level from the not very grand old age of 40. Specific vestibular rehab training exercises have been developed for people diagnosed with definite vestibular problems. But the rest of us will benefit from dynamic movements that require moving the head, like those involved in climbing a tree or practising tai chi, as well as anything that challenges our balance.