Behavioral and Brain Sciences

Coninuing Commentary

Suppression of motion during saccades

David C. Burra1

a1 Istituto di Neurofisiologia del CNR, Pisa, Italy,

Commentary on Bruce Bridgeman, A. H. C. Van der Heijden, and Boris M. Velichkovsky (1994) A theory of visual stability across saccadic eye movements. BBS 17:247–292


Saccadic eye movements create (at least) two related but distinct problems for the visual system: they cause rapid image motion and a displacement of the retinal image. Although it is often assumed that the motion is too fast to be resolved, this is certainly not the case for low-spatial-frequency images. Recent experiments have suggested that the reason we are unaware of the motion during saccades is because motion channels are selectively suppressed, possibly by suppression of the magno-cellular (but not the parvocellular) pathway. This suppression may explain why there is no sensation of motion during saccades, but it leaves open the problem of perceiving a stable world despite continual image displacements.