M. Monwilliams et Jr. Tresilian, A FRAMEWORK FOR CONSIDERING THE ROLE OF AFFERENCE AND EFFERENCE IN THE CONTROL AND PERCEPTION OF OCULAR POSITION, Biological cybernetics, 79(2), 1998, pp. 175-189
It has been well established that extra-retinal information is used in
the perception of visual direction and distance. Furthermore, a numbe
r of studies have established that both efference copy and afferent di
scharge contribute to the extra-retinal signal. Despite this, no model
currently exists to explain how the signals which arise through oculo
motor control contribute to perception. This paper attempts to provide
such a framework. The first part of the paper outlines the framework
[the cyclopean equilibrium point (EP) model] and considers the binocul
us or cyclopean eye from the perspective of a current account of motor
control (the EP hypothesis). An existing model is used to describe ho
w the nervous system could utilise available efference copy and affere
nt extra retinal signals when determining the direction and distance o
f cyclopean fixation. Although the cyclopean EP model is speculative,
it allows for a parsimonious framework when considering the oculomotor
contribution to perception. The model has the additional advantage of
being consistent with current theories regarding the control and perc
eption of limb movement. The second part of the paper shows that the m
odel is biologically plausible, demonstrates the use of the proposed m
odel in describing the central control of eye movements with regard to
non-conjugate peripheral adaptation and reconciles seemingly disparat
e empirical findings.