Spontaneous movements of objects and other unexplained effects have been reported, and many parapsychologists believe these are possibly forms of psychokinesis/telekinesis. Parapsychologist William G. Roll coined the term "recurrent spontaneous psychokinesis" (RSPK) in 1958.
The sudden movement of objects without deliberate intention in the presence or vicinity of one or more witnesses is thought by some to be related to as-yet-unknown PK/TK processes of the subconscious mind. Some researchers use the term "PK agent," especially in spontaneous cases, to describe someone who is suspected of being the source of the PK action.
Outbreaks of spontaneous movements or other effects, such as in a private home, and especially those involving violent or physiological effects, such as objects hitting people or scratches or other marks on the body, are sometimes investigated as cases.