Just in time for Halloween, researchers are releasing new data that show darkness increases the impact of social stress, in an article scheduled for publication in the November 15th issue of Biological Psychiatry.
As children and adults alike gear up for the anticipation and excitement of this “spooky” holiday, this study lends a further understanding to our inherent fear of the dark.
Grillon and colleagues at the National Institute of Mental Health sought to examine whether stress increases unconditioned fear in humans. To do this, they measured the startle reflex of healthy volunteers in either light or dark conditions, and after either a socially stressful situation of public speaking, or after a period of relaxation. The startle response is a sensitive tool for measuring anxiety levels, and in this study, was measured when volunteers were presented with white noise stimuli via headphones. The authors found that the startle response was boosted when the volunteers were in complete darkness, and this effect was more pronounced after the stressor.
Dr. Christian Grillon, lead author on the project, explains, “Because stress has been linked to the precipitation of emotional disturbances, sometimes to a pathological level, it is important to understand how stress affects our brain and behavior.” He adds, “We report that a mild acute stressor increases subsequent experimental anxiety in healthy subjects. The demonstration of stress-induced anxiety in the laboratory is important because it provides how stress alters nervous system function.”