title: Task-switching effects for visual and auditory pro- and antisaccades: evidence for a task-set inertia.
abstract: The completion of an antisaccade delays the reaction time (RT) of a subsequent prosaccade; however, the converse switch does not influence RT. In accounting for this result, the task-set inertia hypothesis contends that antisaccades engender a persistent nonstandard task-set that delays the planning of a subsequent prosaccade. In contrast, the coordinate system transformation hypothesis asserts that the transformation required to construct a mirror-symmetrical target representation persistently inhibits prosaccade planning. The authors tested the latter hypothesis by examining switch-costs for pro- and antisaccades directed to visual (i.e., the stimuli used in previous work) and auditory targets. Notably, auditory cues are specified in a head-centered frame of reference prior to their conversion into the retinocentric coordinates necessary for saccade output. Thus, if the coordinate system transformation hypothesis is correct then auditory pro- and antisaccades should elicit a bidirectional switch-cost because each requires a coordinate transformation. RTs for visual and auditory modalities showed a reliable--and equivalent magnitude--prosaccade switch-cost. Moreover, performance (e.g., movement time) and kinematic (e.g., velocity) variables indicated the switch-cost was restricted to response planning. As such, results are incompatible with the coordinate system transformation hypothesis and therefore provide convergent evidence that a task-set inertia contributes to the prosaccade switch-cost.
authors.affiliation: a School of Kinesiology, The University of Western Ontario , London , Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Heath
authors.forename: Faryn
authors.initials: F
authors.lastname: Starrs
authors.forename: Ewan
authors.initials: E
authors.lastname: Macpherson
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Weiler
mesh_terms: D001307:Auditory Perception / Q000502:physiology*; D003463:Cues; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: antisaccade; auditory; oculomotor; prosaccade; task-switch