Reconsolidation of declarative memory in humans

Abstract

The reconsolidation hypothesis states that a consolidated memory could again become unstable and susceptible to facilitation or impairment for a discrete period of time after a reminder presentation. The phenomenon has been demonstrated in very diverse species and types of memory, including the human procedural memory of a motor skill task but not the human declarative one. Here we provide evidence for both consolidation and reconsolidation in a paired-associate learning (i.e., learning an association between a cue syllable and the respective response syllable). Subjects were given two training sessions with a 24-h interval on distinct verbal material, and afterward, they received at testing two successive retrievals corresponding to the first and second learning, respectively. Two main results are noted. First, the first acquired memory was impaired when a reminder was presented 5 min before the second training (reconsolidation), and also when the second training was given 5 min instead of 24 h after the first one (consolidation). Second, the first retrieval proved to influence negatively on the later one (the retrieval-induced forgetting [RIF] effect), and we used the absence of this RIF effect as a very indicator of the target memory impairment. We consider the demonstration of reconsolidation in human declarative memory as backing the universality of this phenomenon and having potential clinical relevance. On the other hand, we discuss the possibility of using the human declarative memory as a model to address several key topics of the reconsolidation hypothesis.

Disruptive Effect of Midazolam on Fear Memory Reconsolidation: Decisive Influence of Reactivation Time Span and Memory Age

“…Such vulnerability is followed by a stabilization processFusually referred to as reconsolidationFthat requires de novo protein synthesis. Memory reconsolidation has been demonstrated across a variety of species (Anokhin et al, 2002;Suzuki et al, 2004;Sangha et al, 2003;Pedreira and Maldonado, 2003), including humans (Walker et al, 2003;Forcato et al, 2007), and under different learning and memory paradigms motivated by either aversive or rewarding stimuli Lee et al, 2005). All this evidence strongly supports the notion that reconsolidation represents an evolutionarily conserved mnemonic process and accounts for the universality of this phenomenon.…”

“…Furthermore, Lee et al (2008) report the inability of brief reexposure to induce the protein degradation necessary to destabilize the preexisting fear memory. Finally, the absence of MDZ vulnerability after 1 min context exposure confirms that interference after memory reactivation requires the fulfillment of several conditions rather than the single memory retrieval (Pedreira et al, 2004;Forcato et al, 2007). When the reactivation was prolonged up to 3-5 min, the memory trace became gradually vulnerable to disruption as MDZ-treated rats showed less fear than controls.…”

Influence of reward motivation on human declarative memory

“…Recent theories on reconsolidation propose that long-term memory formation implicates memory recollection, because the hippocampus links encoded information to reactivated memories in a continuous cycle of retrieval and learning (Alberini, 2011;Forcato et al, 2007;McKenzie and Eichenbaum, 2011;Stickgold and Walker, 2013). In this context, the circuits modulated by new learning are the ones that are activated by the reminder of a remembered (e.g.…”

Pharmacological effects and behavioral interventions on memory consolidation and reconsolidation

“…The interferences of reactivated memories through more "physiological" approaches were also described by Walker et al (45), Hupbach et al (46), and more recently by Forcato et al (47). All these studies were performed in humans.…”