Semantic congruence accelerates the onset of the neural signals of successful memory encoding

TY - JOUR

T1 - Semantic congruence accelerates the onset of the neural signals of successful memory encoding

AU - Packard, P A

AU - Rodríguez-Fornells, A

AU - Bunzeck, N

AU - Nicolás, B

AU - de Diego-Balaguer, R

AU - Fuentemilla, L

N1 - Copyright © 2016 the authors.

PY - 2017/1/11

Y1 - 2017/1/11

N2 - 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 approximately 200 ms later suggests 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).SIGNIFICANCE STATEMENT: 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 (ERPs) 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.

AB - 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 approximately 200 ms later suggests 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).SIGNIFICANCE STATEMENT: 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 (ERPs) 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.

U2 - 10.1523/JNEUROSCI.1622-16.2016

DO - 10.1523/JNEUROSCI.1622-16.2016

M3 - SCORING: Journal article

C2 - 27903704

VL - 37:

SP - 291

EP - 301

JO - J NEUROSCI

JF - J NEUROSCI

SN - 0270-6474

IS - 2

ER -