From Science Daily:

Anxious people have long been classified as “hypersensitive” — they’re thought to be more fearful and feel threatened more easily than their counterparts. But new research from Tel Aviv University shows that the anxious may not be hypersensitive at all — in fact, they may not be sensitive enough.

As part of a study on how the brain processes fear in anxious and non-anxious individuals, Tahl Frenkel, a Ph.D. candidate in TAU’s School of Psychological Sciences and the Adler Center for Research in Child Developmental and Psychopathology, working with her supervisor Prof. Yair Bar-Haim, measured brain activity as study participants were shown images designed to induce fear and anxiety. Using an EEG to measure electrical activity caused by the neuronal activity that represents deep processing of these stimuli, the researchers discovered that the anxious group was actually less stimulated by the images than the non-anxious group.

Surprisingly, anxious study participants weren’t shown to be as physiologically sensitive to subtle changes in their environment as less fearful individuals, Frenkel explains. She theorizes that anxious people could have a deficit in their threat evaluation capabilities — necessary for effective decision-making and fear regulation — leading to an under-reaction to subtle threatening stimuli. Non-anxious individuals seem to have a subconscious “early warning system,” allowing them to prepare for evolving threats. Essentially, anxious people are “surprised” by fearful stimuli that non-anxious individuals have already subconsciously noticed, analyzed, and evaluated.

This supports our frequent observation of anxiety in children with poorly integrated sensory processing, who tend to selectively attend to one mode of sensation (typically vision) to the exclusion of the conflicting or incongruous input. They lack the kind of flexible shifting of attention that would allow them to alert and orient to the subtle environmental cues that would otherwise help them anticipate changes, transitions, and other events with enough time to generate a purposeful response. Instead, they tend to react with a fight/flight response and often make attempts to avoid this kind of ambiguity by adhering to predictable routines and controlling the actions of others with their own emotions and behavior. 

When confronted with a potential threat, Frenkel concluded, non-anxious people unconsciously notice subtle changes in the environment before they consciously recognize the threat. Lacking such preparation, anxious individuals often react more strongly, as the threat takes them more “by surprise.”

“The EEG results tell us that what looks like hypersensitivity on a behavioral level is in fact the anxious person’s attempt to compensate for a deficit in the sensitivity of their perception,” she explains.

Read the article here.