title: Reinforcing saccadic amplitude variability in a visual search task.
abstract: Human observers often adopt rigid scanning strategies in visual search tasks, even though this may lead to suboptimal performance. Here we ask whether specific levels of saccadic amplitude variability may be induced in a visual search task using reinforcement learning. We designed a new gaze-contingent visual foraging task in which finding a target among distractors was made contingent upon specific saccadic amplitudes. When saccades of rare amplitudes led to displaying the target, the U values (measuring uncertainty) increased by 54.89% on average. They decreased by 41.21% when reinforcing frequent amplitudes. In a noncontingent control group no consistent change in variability occurred. A second experiment revealed that this learning transferred to conventional visual search trials. These results provide experimental support for the importance of reinforcement learning for saccadic amplitude variability in visual search.
authors.affiliation: Laboratoire Ureca, UFR de Psychologie, Université Lille Nord de France, Villeneuve d'Ascq, FranceLaboratoire Psychologie de la Perception, Université Paris Descartes, Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Paeye
authors.affiliation: Laboratoire Ureca, UFR de Psychologie, Université Lille Nord de France, Villeneuve d'Ascq, France Institut de Neurosciences de la Timone, Centre National de la Recherche Scientifique, Marseille, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Madelain
mesh_terms: D000293:Adolescent; D000328:Adult; D003216:Conditioning, Operant; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time; D012054:Reinforcement, Psychology; D012438:Saccades / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: reinforcement learning; saccades; variability; visual search