The simple experiment that involves just sitting alone in a quiet room and staring at a mirror for approximately 15 minutes is very likely to result in your brain creating “a monster” or basically just something to freak you out. The reason for that happening is strictly biological : if the brain is faced with a lot of stimulation, it would phase out the non-relevant information from the surroundings and just focus on the relevant. The effect was first discovered in 1804 by the physician Ignaz Troxler and is known as the Troxler Effect or the Troxler Fading. The effect is known to fade out the features of the face as soon as the person stops staring directly at them thus distorting them in a horrifying way. As the brain gets tired of the mundane, it instinctively turns the distortions into something scary just to entertain us.