title: Top-down knowledge modulates onset capture in a feedforward manner.
abstract: How do we select behaviourally important information from cluttered visual environments? Previous research has shown that both top-down, goal-driven factors and bottom-up, stimulus-driven factors determine which stimuli are selected. However, it is still debated when top-down processes modulate visual selection. According to a feedforward account, top-down processes modulate visual processing even before the appearance of any stimuli, whereas others claim that top-down processes modulate visual selection only at a late stage, via feedback processing. In line with such a dual stage account, some studies found that eye movements to an irrelevant onset distractor are not modulated by its similarity to the target stimulus, especially when eye movements are launched early (within 150-ms post stimulus onset). However, in these studies the target transiently changed colour due to a colour after-effect that occurred during premasking, and the time course analyses were incomplete. The present study tested the feedforward account against the dual stage account in two eye tracking experiments, with and without colour after-effects (Exp. 1), as well when the target colour varied randomly and observers were informed of the target colour with a word cue (Exp. 2). The results showed that top-down processes modulated the earliest eye movements to the onset distractors (<150-ms latencies), without incurring any costs for selection of target matching distractors. These results unambiguously support a feedforward account of top-down modulation.
authors.affiliation: School of Psychology, The University of Queensland, Brisbane, Australia. s.becker@psy.uq.edu.au.
authors.forename: Stefanie I
authors.initials: SI
authors.lastname: Becker
authors.affiliation: School of Psychology, The University of Queensland, Brisbane, Australia.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Lewis
authors.affiliation: School of Psychology, The University of Queensland, Brisbane, Australia.
authors.forename: Jenna E
authors.initials: JE
authors.lastname: Axtens
mesh_terms: D000328:Adult; D001288:Attention; D003118:Color Perception; D004193:Discrimination Learning; D005133:Eye Movements; D005260:Female; D005364:Field Dependence-Independence; D006040:Goals; D006801:Humans; D008297:Male; D009042:Motivation; D010364:Pattern Recognition, Visual; D010470:Perceptual Masking; D011793:Queensland; D011930:Reaction Time; D055815:Young Adult
keywords: Attentional capture; Cognitive control and automaticity; Eye movements and visual attention; Visual search