title: First come, last primed: FN400 reflects post-encoding editing of the memory trace.
abstract: Explicit associative memory relies on different neural substrates depending on similarity of the items associated. Extant literature dissociates old/new effects elicited by homogeneous and heterogeneous pairs. However, current results scarcely address potential priming effects induced by the presentation sequence. In the present ERP study, participants learned associations between two pictures, which either belonged to the same semantic category (e.g., animal-animal), or to different categories (e.g., animal-scene). Pictures forming a pair were shown sequentially, allowing for investigation of the different neural processes related to presentation of the first and the second item. After the study phase, participants performed a recognition judgment. After recognition, participants were asked to recall the associated picture. During retrieval, between 260 and 350 ms post-stimulus there was a significant frontal effect of category (i.e., same-category versus different-category), but only for items shown first within a pair. In the 350-600 ms time window the parietal old/new effect was unaffected by semantic category, but was modulated by presentation order. Exploratory analyses revealed even earlier effects in the time windows 40-90 ms and 150-200 ms. This evidence supports the priming account of the FN400 and highlights the importance of sequence effects in electrophysiological activity during episodic retrieval.
authors.affiliation: Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari - 'Aldo Moro', Piazza Giulio Cesare, 11, I-70100 Bari, Italy; Cognitive Neuroscience Sector, International School for Advanced Studies (SISSA), via Bonomea 265, I-34136 Trieste, Italy. Electronic address: giuliopergola@yahoo.it.
authors.forename: Giulio
authors.initials: G
authors.lastname: Pergola
authors.affiliation: Department of Neuropsychology, Ruhr-University Bochum, D-44780 Bochum, Germany; Institute of Experimental Psychology, Heinrich Heine University Düsseldorf, Universitaetsstrasse 1, 40225 Düsseldorf, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Bellebaum
authors.affiliation: Department of Neuropsychology, Ruhr-University Bochum, D-44780 Bochum, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Suchan
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D021641:Recognition, Psychology / Q000502:physiology*; D012660:Semantics; D055815:Young Adult
keywords: Associative encoding; Conceptual priming; Event-related potential; FN400; Frontal negativity