title: Response to an intervening event reverses nonspatial repetition effects in 2AFC tasks: nonspatial IOR?
abstract: The repetition effect in two-alternatiave forced choice (2AFC) tasks is a cornerstone effect in human cognition. Yet the experiments described here show that the customary benefit of repetition reverses to a cost of repetition when participants respond to an irrelevant event between targets. In Experiments 1A-1C, participants made manual 2AFC decisions to both of two consecutive targets on a trial and, on some trials, also made a manual response to an intervening event that appeared between the two targets. A repetition benefit was observed when no intervening event appeared, whereas a repetition cost was observed when a response was required to an intervening event. Experiment 2 ruled out a solely strategic interpretation of the repetition cost effect observed on intervening event trials. In Experiments 3A and 3B, an intervening event that required a simple vocal "go" response also produced a repetition cost. In Experiment 4, a repetition cost was observed when the intervening event was changed to a tone presented aurally. In Experiment 5, the repetition benefit was observed when a response was withheld to an intervening event. A dual-process interpretation of these results is discussed, with one process related to episodic integration, and the other related to processes that produce inhibition of return.
authors.affiliation: Department of Psychology, Neuroscience, and Behaviour, McMaster University, Hamilton, Ontario, Canada. spadaraj@mcmaster.ca
authors.forename: Adam
authors.initials: A
authors.lastname: Spadaro
authors.forename: Chao
authors.initials: C
authors.lastname: He
authors.forename: Bruce
authors.initials: B
authors.lastname: Milliken
mesh_terms: D001245:Association Learning; D001288:Attention; D001307:Auditory Perception; D002755:Choice Behavior; D003118:Color Perception; D004192:Discrimination, Psychological; D006801:Humans; D007266:Inhibition, Psychological; D009949:Orientation; D010364:Pattern Recognition, Visual; D011930:Reaction Time; D012193:Reversal Learning; D012660:Semantics; D012858:Size Perception