title: Saccadic adaptation induced by a perceptual task.
abstract: The human motor system and muscles are subject to fluctuations in the short and long term. Motor adaptation is classically thought of as a low-level process that compensates for the error between predicted and executed movements in order to maintain movement accuracy. Contrary to a low-level account, accurate movements might be only a means to support high-level behavioral and perceptual goals. To isolate the influence of high-level goals in adaptation of saccadic eye movements, we manipulated perceptual task requirements in the absence of low-level errors. Observers had to discriminate one character within a peripheral array of characters. Between trials, the location of this character within the array was changed. This manipulation led to an immediate strategic change and a slower, gradual adaptation of saccade amplitude and direction. These changes had a similar magnitude to classical saccade adaptation and transferred at least partially to reactive saccades without a perceptual task. These results suggest that a perceptual task can modify oculomotor commands by generating a top-down error signal in saccade maps just like a bottom-up visual position error. Hence saccade adaptation not only maintains saccadic targeting accuracy, but also optimizes gaze behavior for the behavioral goal, showing that perception shapes even low-level oculomotor mechanisms.
authors.affiliation: Abteilung Allgemeine Psychologie, Justus Liebig Universität Gießen, Giessen, Germany.
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Schütz
authors.forename: Dirk
authors.initials: D
authors.lastname: Kerzel
authors.forename: David
authors.initials: D
authors.lastname: Souto
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology*; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D012438:Saccades / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: eye movements; motor adaptation; visual perception