title: Semantic Congruence Accelerates the Onset of the Neural Signals of Successful Memory Encoding.
abstract: As the stream of experience unfolds, our memory system rapidly transforms current inputs into long-lasting meaningful memories. A putative neural mechanism that strongly influences how input elements are transformed into meaningful memory codes relies on the ability to integrate them with existing structures of knowledge or schemas. However, it is not yet clear whether schema-related integration neural mechanisms occur during online encoding. In the current investigation, we examined the encoding-dependent nature of this phenomenon in humans. We showed that actively integrating words with congruent semantic information provided by a category cue enhances memory for words and increases false recall. The memory effect of such active integration with congruent information was robust, even with an interference task occurring right after each encoding word list. In addition, via electroencephalography, we show in 2 separate studies that the onset of the neural signals of successful encoding appeared early (∼400 ms) during the encoding of congruent words. That the neural signals of successful encoding of congruent and incongruent information followed similarly ∼200 ms later suggests that this earlier neural response contributed to memory formation. We propose that the encoding of events that are congruent with readily available contextual semantics can trigger an accelerated onset of the neural mechanisms, supporting the integration of semantic information with the event input. This faster onset would result in a long-lasting and meaningful memory trace for the event but, at the same time, make it difficult to distinguish it from plausible but never encoded events (i.e., related false memories).
  
  
  
  Conceptual or schema congruence has a strong influence on long-term memory. However, the question of whether schema-related integration neural mechanisms occur during online encoding has yet to be clarified. We investigated the neural mechanisms reflecting how the active integration of words with congruent semantic categories enhances memory for words and increases false recall of semantically related words. We analyzed event-related potentials during encoding and showed that the onset of the neural signals of successful encoding appeared early (∼400 ms) during the encoding of congruent words. Our findings indicate that congruent events can trigger an accelerated onset of neural encoding mechanisms supporting the integration of semantic information with the event input.
authors.affiliation: Cognition and Brain Plasticity Group (Bellvitge Biomedical Research Institute) IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain, pau.packard@uni-luebeck.de.|Department of Cognition, Development and Educational Psychology, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain.|Department of Psychology, University of Lübeck, 23562 Lübeck, Germany.
authors.forename: Pau A
authors.initials: PA
authors.lastname: Packard
authors.affiliation: Cognition and Brain Plasticity Group (Bellvitge Biomedical Research Institute) IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain.|Department of Cognition, Development and Educational Psychology, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain.|Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Rodríguez-Fornells
authors.affiliation: Department of Psychology, University of Lübeck, 23562 Lübeck, Germany.|Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany, and.
authors.forename: Nico
authors.identifier: 0000-0001-8834-450X
authors.initials: N
authors.lastname: Bunzeck
authors.affiliation: Cognition and Brain Plasticity Group (Bellvitge Biomedical Research Institute) IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain.|Department of Cognition, Development and Educational Psychology, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain.
authors.forename: Berta
authors.identifier: 0000-0002-3819-0968
authors.initials: B
authors.lastname: Nicolás
authors.affiliation: Cognition and Brain Plasticity Group (Bellvitge Biomedical Research Institute) IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain.|Department of Cognition, Development and Educational Psychology, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain.|Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain.|Institute of Neurosciences, University of Barcelona, Barcelona 08193, Spain.
authors.forename: Ruth
authors.identifier: 0000-0001-5576-2887
authors.initials: R
authors.lastname: de Diego-Balaguer
authors.affiliation: Cognition and Brain Plasticity Group (Bellvitge Biomedical Research Institute) IDIBELL, L'Hospitalet de Llobregat, Barcelona 08908, Spain.|Department of Cognition, Development and Educational Psychology, University of Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain.|Institute of Neurosciences, University of Barcelona, Barcelona 08193, Spain.
authors.forename: Lluís
authors.initials: L
authors.lastname: Fuentemilla
mesh_terms: D000328:Adult; D003463:Cues; D004569:Electroencephalography / Q000379:methods*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D057567:Memory, Long-Term / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D011897:Random Allocation; D012660:Semantics; D055815:Young Adult
keywords: EEG; congruence; episodic memory; schemas; successful encoding