title: Synchronous contextual irregularities affect early scene processing: replication and extension.
abstract: Whether contextual regularities facilitate perceptual stages of scene processing is widely debated, and empirical evidence is still inconclusive. Specifically, it was recently suggested that contextual violations affect early processing of a scene only when the incongruent object and the scene are presented a-synchronously, creating expectations. We compared event-related potentials (ERPs) evoked by scenes that depicted a person performing an action using either a congruent or an incongruent object (e.g., a man shaving with a razor or with a fork) when scene and object were presented simultaneously. We also explored the role of attention in contextual processing by using a pre-cue to direct subjects׳ attention towards or away from the congruent/incongruent object. Subjects׳ task was to determine how many hands the person in the picture used in order to perform the action. We replicated our previous findings of frontocentral negativity for incongruent scenes that started ~ 210 ms post stimulus presentation, even earlier than previously found. Surprisingly, this incongruency ERP effect was negatively correlated with the reaction times cost on incongruent scenes. The results did not allow us to draw conclusions about the role of attention in detecting the regularity, due to a weak attention manipulation. By replicating the 200-300 ms incongruity effect with a new group of subjects at even earlier latencies than previously reported, the results strengthen the evidence for contextual processing during this time window even when simultaneous presentation of the scene and object prevent the formation of prior expectations. We discuss possible methodological limitations that may account for previous failures to find this an effect, and conclude that contextual information affects object model selection processes prior to full object identification, with semantic knowledge activation stages unfolding only later on.
authors.affiliation: Department of Psychology, Tel Aviv University, PO Box 39040, Tel Aviv 69978, Israel; Division of Biology, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA. Electronic address: liadmu@gmail.com.
authors.forename: Liad
authors.initials: L
authors.lastname: Mudrik
authors.affiliation: Department of Cognitive Science, The Hebrew University of Jerusalem, Jerusalem 91905, Israel.
authors.forename: Shani
authors.initials: S
authors.lastname: Shalgi
authors.affiliation: Department of Psychology, Tel Aviv University, PO Box 39040, Tel Aviv 69978, Israel.
authors.forename: Dominique
authors.initials: D
authors.lastname: Lamy
authors.affiliation: Department of Psychology and the Edmond and Lily Safra Center for brain sciences, The Hebrew University of Jerusalem, Jerusalem 91905, Israel.
authors.forename: Leon Y
authors.initials: LY
authors.lastname: Deouell
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D004192:Discrimination, Psychological / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D010775:Photic Stimulation; D011930:Reaction Time; D013997:Time Factors; D055815:Young Adult
keywords: Context effects; Event-related potentials; Incongruency; Matching models; N300/N400; Visual scenes