Shadow people

Shadow people (also known as shadow ghosts, shadow figures, shadow beings,shadow men, or shadow folk) are supernatural shadow-like humanoid figures that, according to believers, are seen mostly in peripheral vision. They are commonly regarded in modern folklore and paranormal popular culture as malicious or evil spirits.

Paranormal popular culture
Shadow people are typically described as black humanoid silhouettes with no discernible mouths, noses, or facial expressions; child-sized humanoids; or shapeless masses that sometimes change to human like form and featuring eyes that are either glowing or not discernable. Movement is said to be quick and disjointed, and some stories describe the visible outline of a cloak, or a 1930s style fedora hat.[2] [self-published source?]

[edit]Scientific explanations
Several scientific principles can be used to explain reports of shadow people, including optical illusions or hallucinations brought on by physiological/psychological circumstances, drug use or side effects of medication, and the interaction of external agents on the human body.

An illusion of a shadow person can be created when the left temporoparietal junction, a specific region of the brain, is stimulated.[3]

Images seen in peripheral areas of vision can be caused by pareidolia, a condition in which the brain incorrectly interprets random patterns of light/shadow or texture as being familiar patterns such as faces and human forms.[4]

Hypnagogia, also known as "waking-sleep", a physiological condition in which a person is part-way between sleeping and waking, can also account for such perceptions.[5] During hypnagogia, a person can be conscious and aware of their environment, but also in a dream-like state where they can perceive images from their subconscious. People experiencing waking-sleep commonly report the sensation of lights or shadows moving around them, as well as other visual hallucinations. A feeling of dread is also a sensation that occurs when experiencing hypnagogia. Hypnagogia is sometimes known as 'the faces in the dark phenomenon' because those who experience this state commonly report seeing faces while experiencing waking-sleep.[6]