Some recent studies on the quantitative analysis of efference copy mechanisms in visual perception

Abstract

The idea of ‘cancellation’ between afferent visual movement signals and corollary signals evoked by the motor commands of gaze movement (now called efference copy signals) was first proposed by Purkyně. It was further developed during the 19th century by leading sensory physiologists such as Hering, Helmholtz, Mach and their pupils, and was more precisely described in the ‘reafference principle’ by Von Holst and Mittelstaedt (1950). During the last 20 years, experimental paradigms were developed by which a quantitative study of the interaction of efference copy in visual movement and space perception became possible. Some results obtained with such paradigms are described: smooth pursuit eye movements and movement perception evoked by stabilized retinal images, open-loop optokinetic nystagmus and corresponding movement perception, Sigma-optokinetic nystagmus and Sigma-pursuit movement, the time course of the recalibration of retinal spatial values during and after saccadic eye movements.