Close talkers, crowded buses: everybody needs a certain amount of personal space. A new study announced Monday reveals exactly how much most of us need, and finds that anxious people need a bit more.

University College London researchers say that generally most people need a boundary from around 20 to 40 centimeters in front of their face before becoming tense.

Findings were published in The Journal of Neuroscience.

In the study, the researchers attached electrodes that delivered small electric shocks to the hands of 15 healthy people. Each subject also wore a device that measured the electrical activation of the muscles used to blink, a classic defensive reaction, the researchers said. They then compared the reflex data to the results of an anxiety test where subjects rated their levels of anxiety in various situations.

During the experiments, subjects also held out one hand at varying distances from their face -- 4, 20, 40 and 60 cm -- and received a shock, while the scientists measured how strongly the participants blinked in response.

The blinking reflex intensified when the stimuli to the hand was a certain distance from the eye, coauthor Giandomenico Iannetti explained. In addition, those who scored highly on the anxiety test tended to react more strongly to the stimuli 20 centimeters from their face than subjects who got low scores on the anxiety test.

Access the study here.