Do you ever get so stressed with work, home life, or school that you feel like all of your burdens could fill a whole room? You’re not crazy or being melodramatic, according to new research from University College London (UCL), but rather the anxiety in your mind is increasing the physical boundaries of your comfort zone. The results of this study may explain why certain moods can trigger feelings of claustrophobia, the fear of small spaces.

To define a person’s physical comfort zone — known as the peripersonal space — researchers at UCL watched people blink. All individuals reflexively blink when electrical stimulation is applied to a particular nerve in the hand.

Psychologists believe this instinctive behavior helps the mind assess threats of danger, given the hand-blink reflex speeds up when the peripersonal space is invaded by someone else. In the case of this, another person’s hand was placed in front of a subject’s face.

Using this blink reflex as a guide, the scientists found the boundaries for personal space were about eight to 15 inches away from the body — or the width of a sheet of notebook paper.

"This finding is the first objective measure of the size of the area surrounding the face that each individual considers at high-risk, and thus wants to protect through the most effective defensive motor responses," said co-lead author Dr. Giandomenico Iannetti, a neuroscientist at UCL.

The 15 subjects in the study were also asked to complete an anxiety test, and the researchers found that those with higher anxiety had bigger peripersonal spaces.

“These findings point to the potential for measuring a range of defensive behaviors in relation to individual levels of anxiety,” concluded the authors. “The availability of such measures will allow developing procedures to test risk assessment abilities, particularly in professions that require reacting quickly to aversive stimuli near the body, such as firemen, policemen, and military officers.”

Source: Sambo CF, Iannetti GD. Better Safe Than Sorry? The Safety Margin Surrounding the Body Is Increased by Anxiety. Journal of Neuroscience. 2013.