Understanding your character's sixth-sense for danger: Here's how it works.

Credit: © Dario Lo Presti / Fotolia

Anxious individuals detect threat in a different region of the

brain from people who are more laid-back.

Characters having a sixth-sense for danger borders on cliché, a trope even.

Yet, many if not most clichés are a statement of the obvious.  We as humans do have a sixth sense for danger, and as with most characteristics some of us have a sharper sense of impending danger, and some have less.

Researchers in France are investigating the relationship between this sixth-sense and anxiety, how it functions in different people, and when it is a healthy reaction and when it's not.

Is this sixth-sense extra-sensory?  Not from what I understand about brain science.  Significant research using fMRI and other technology reveals that most processing in our brain takes place out of the notice of our conscious mind, and alerts us to a potential threat in far less time than our conscious mind can register.

So when a section of our brain notes an angry look on the face of someone staring directly at us in a social situation, we feel anxious.  This is our subconscious mind alerting us to potential danger so that our conscious mind can work to identify the threat.

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Being anxious could be good for you in a crisis

Brain prioritizes threats, especially in anxious people

Seeing anger paired with a direct gaze produces 

a response in the brain in only 200 milliseconds.

New findings could help explain the apparent 'sixth sense' we have for danger in social situations, with the direction of a person's gaze being a crucial cue. People with non-clinical anxiety are particularly well poised for action.

The results in the journal eLife may help explain the apparent "sixth sense" we have for danger. This is the first time that specific regions of the brain have been identified to be involved in the phenomenon. The human brain is able to detect social threats in these regions in a fast, automatic fashion, within just 200 milliseconds.

Even more surprising for the scientists was the discovery that anxious individuals detect threat in a different region of the brain from people who are more laid-back. It was previously thought that anxiety could lead to over-sensitivity to threat signals. However, the new study shows that the difference has a useful purpose.

• Anxious people process threats using regions of the brain responsible for action. 
• Meanwhile, 'low anxious' people process them in sensory circuits, responsible for facial recognition.

Facial displays of emotion can be ambiguous but the researchers managed to identify what it is that makes a person particularly threatening. They found that the direction a person is looking in is key to enhancing our sensitivity to their emotions. Anger paired with a direct gaze produces a response in the brain in only 200 milliseconds, faster than if the angry person is looking elsewhere.

"In a crowd, you will be most sensitive to an angry face looking towards you, and will be less alert to an angry person looking somewhere else," says lead author Marwa El Zein from the French Institute of Health and Medical Research (INSERM) and the Ecole Normale Supérieurein Paris.

Seeing fear in others triggers our sixth-sense
Similarly, if a person displays fear and looks in a particular direction you will detect this more rapidly than positive emotions. Such quick reactions could have served an adaptive purpose for survival. For example, we evolved alongside predators that can attack, bite or sting. A rapid reaction to someone experiencing fear can help us avoid danger.

"In contrast to previous work, our findings demonstrate that the brain devotes more processing resources to negative emotions that signal threat, rather than to any display of negative emotion," says El Zein.

Electrical signals measured in the brains of 24 volunteers were analysed while they were asked to decide whether digitally altered faces expressed anger or fear. Some faces displayed exactly the same expression, but the direction of their gaze was altered. A total of 1080 trials were carried out.

It has often been theorized that elevated anxiety, even in a non-clinical range, could impair the brain's processing of threats. However, El Zein and her co-authors instead found that non-clinical anxiety shifts the neural 'coding' of threat to motor circuits, which produce action, from sensory circuits, which help us to recognize faces. The researchers note that it would be interesting to determine whether the same is true for people with anxiety scores in the clinical range.

Story Source:  Materials provided by eLife.  Marwa El Zein, Valentin Wyart, Julie Grèzes. Anxiety dissociates the adaptive functions of sensory and motor response enhancements to social threats. eLife, 2015.