Conscious and subconscious arm movements: Application of signal detection theory to motor control

Abstract

People sometimes carry out voluntary movements that do not seem to be consciously controlled. A familiar example is the board game Ouija. We hypothesize that movement speed is a primary determinant of whether a movement is conscious or subconscious. In support of this hypothesis, we show that mean movement velocity is slower when subjects imagine “a force pushing against the arm” than when they move the arm “as slowly as possible.” We also show that this outcome can be accounted for with signal detection theory, a theoretical tool that has so far been used primarily in the areas of perception and memory. © 1984, The psychonomic Society, Inc.. All rights reserved.