Studying saccades can illuminate the more complex decision-making processes required for everyday movements. The double-step task, in which a target jumps to two successive locations before the subject has time to react, has proven a powerful research tool to investigate the brain's ability to program sequential responses. We asked how @entity1 with a range of @entity76 responded to the double-step task, specifically, whether the initial saccadic response made to a target is affected by the appearance of a second target jump. We also sought to determine whether cerebellar @entity1 were able to make corrective saccades towards the remembered second target location if it were turned off soon after presentation. We tested saccades to randomly interleaved single- and double-step target jumps to eight locations on a circle. @entity1 's initial responses to double-step stimuli showed 50% more error than saccades to single target jumps, and often, they failed to make a saccade to the first target jump. The presence of a second target jump had similar, but smaller effects in control subjects (error increased by 18%). During memory-guided double-step trials, both @entity1 and controls made corrective saccades in darkness to the remembered location of the second jump. We conclude that in cerebellar @entity1 , the second target jump interferes with programming of the saccade to the first target jump of a double-step stimulus; this defect highlights @entity1 ' impaired ability to respond appropriately to sudden, conflicting changes in their environment. Conversely, since cerebellar @entity1 can make corrective memory-guided saccades in darkness, they retain the ability to remember spatial locations, possibly due to non-retinal neural signals (corollary discharge) from cerebral hemispheric areas concerned with spatial localization.

Effects of XXXX on sequences of rapid eye movements.

@entity1 :: ('9606', 'Species') :: ['patients', 'Patient'] @entity76 :: ('MESH:D002526', 'Disease') :: ['cerebellar disorders']
@entity76 :: (MESH:D002526,Disease) :: ['cerebellar disease']
