Suppression of displacement in severely slowed saccades

Severely slowed saccades in Spinocerebellar ataxia have previously been shown to be at least partially closed-loop in nature, their long duration means that they can be modified in-flight in response to intrasaccadic target movements. In this study, a woman with these pathologically slowed saccades could modify them in-flight in response to target movements, even when saccadic suppression of displacement (SSD) prevented conscious awareness of those movements. Thus, SSD is not complete, in that it provides perceptual information that is sub-threshold to consciousness but which can still be effectively utilised by the oculomotor system. (C) 2000 Elsevier Science Ltd. All rights reserved.