title: Smooth pursuit initiation in young and elderly subjects.
abstract: Smooth pursuit initiation to step-ramp stimuli was investigated in normal subjects, young and elderly. Older subjects had significant reductions in initial pursuit acceleration before saccades, and in post-saccadic and peak pursuit velocities. Aging impairs the open-loop performance of the pursuit system, possibly by decreasing sensitivity to retinal image motion or by limiting the conversion of visual motion signals into commands for smooth pursuit. Lower open-loop pursuit gain degrades steady-state, closed-loop smooth pursuit in senescence. Our elderly subjects also made less accurate saccades to moving targets, implying defective use of visual motion information by the saccadic system.
authors.affiliation: Neuro-ophthalmology Unit, Toronto Hospital Neurological Center.
authors.forename: M J
authors.initials: MJ
authors.lastname: Morrow
authors.forename: J A
authors.initials: JA
authors.lastname: Sharpe
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology; D011698:Pursuit, Smooth / Q000502:physiology*; D012438:Saccades / Q000502:physiology; D013997:Time Factors