Ideomotor effect in the context of Automatic writing

Table-turning (also known as table-tapping, table-tipping or table-tilting) is a type of séance in which participants sit around a table, place their hands on it, and wait for rotations. The table was purportedly made to serve as a means of communicating with the spirits; the alphabet would be slowly spoken aloud and the table would tilt at the appropriate letter, thus spelling out words and sentences. The process is similar to that of a Ouija board. Scientists and skeptics consider table-turning to be the result of the ideomotor effect, or of conscious trickery.

A planchette ( /plɑːnˈʃɛt/ or /plænˈʃɛt/), from the French for "little plank", is a small, usually heart-shaped flat piece of wood equipped with two wheeled casters and a pencil-holding aperture pointing downwards, used to facilitate automatic writing. The use of planchettes to produce mysterious written messages gave rise to the belief that the devices foster communication with spirits as a form of mediumship. The devices were popular in séances during the Victorian era, before their eventual evolution into the simpler, non-writing pointing devices for ouija boards that eclipsed the popularity of their original form. Scientists explain the motion is due to the ideomotor effect, but paranormal advocates believe the planchette is moved by the presence of spirits or some form of subtle energy.

Planchettes took on a variety of forms during the height of their popularity. American planchettes were traditionally heart- or shield-shaped, but manufacturers produced a wide range of shapes and sizes hoping to distinguish themselves in the highly competitive and profitable market of the devices' late-1860s heyday. Manufacturers espoused the wonders and benefits of different materials (including various hardwoods, India rubber, and even glass), insulated casters, and various attachments meant to "charge" the devices or insulate the user from malevolent spirits. In Great Britain, planchettes took on the classical shapes popularized in early illustrations and newspaper depictions, with round, blunt noses and flat backs. Regardless of their shape or country of origin, almost all planchettes were equipped with brass casters and small wheels of bone or plastic, and their sometimes lavishly illustrated boxes were often packed with blank parchment, pencils, ouija-like folding letter sheets, and esoteric instructions espousing the mysterious communicative powers of the items.