Memory reconsolidation as a tool to endure encoding deficits in elderly

Abstract

Normal aging involves changes in the ability to acquire, consolidate and recall new information. It has been recently proposed that the reconsolidation process is also affected in older adults. Reconsolidation is triggered after reminder presentation, allowing memories to be modified: they can be impaired, strengthened or changed in their content. In young adults it was previously shown that the presentation of repetitive reminders induces memory strengthening one day after reactivation and the presentation of at least one reminder increases memory persistence several days after reactivation. However, until now this process has remained elusive in older adults. We hypothesize that older adults need a stronger reminder to induce memory strengthening through the reconsolidation process than young adults. To test this, we perform a three-day experiment. On day 1, participants learned 15 sound-word associations, on day 2 they received no reminders (NR group), one reminder (R group) or two rounds of reactivations (Rx2 group). Finally, they were tested on day 7. We found that, contrary to our hypothesis, older adults show a memory improvement triggered by repeated labilization/reconsolidation processes to an equal extent than young adults. These results open new perspectives into the use of reconsolidation to improve daily acquired information and the development of therapeutic home used tools to produce memory enhancement in healthy older adults or those with cognitive decline.

Improvement of episodic memory retention by a memory reactivation intervention across the lifespan: from younger adults to amnesic patients.

“…(32) showed that memory reactivation during a nap enhances skill performance. Others studies on episodic memory reconsolidation, indicated that memory reactivation strengthens the performance of older adults when tested two or seven days later (33,34). Similar results were found using transcranial Direct Current Stimulation (35).…”

“…The study of memory reactivation and stabilization at long delays in populations with memory deficits is absent. Only recent work examined memory reactivation in older adults with limited evidence (31,32,34). The current findings provide evidence that memory reactivation facilitates episodic memory stabilization and improves memory retention at long delays across the lifespan.…”

Modulation of memory reconsolidation by adjacent novel tasks: timing defines the nature of change

“…Other studies evaluated the possibility of enhancing human memory during reconsolidation. Those assessed the sole effect of a reactivation session and also its eventual association with re-acquisition sessions, mild stressors, or physical exercise 33 , 35 , 36 , 59 – 61 . Our research along with Wang’s previous work 21 , emphasizes the significance of assessing the timing for associating behavioral events with reactivation sessions to enhance memory and persistence.…”

The Intersection of Offline Learning and Rehabilitation

“…For example, regaining independence in performing activities of daily living involves learning processes (Bayona et al, 2005). Importantly, older adults have been shown to benefit from reconsolidation (Corbin, 2017;Tassone et al, 2020) despite the known declines in consolidation related to healthy aging (Brown et al, 2009;Wilson et al, 2012;Fogel et al, 2014;Roig et al, 2014). However, one study found that reconsolidation was impaired in older adults with stroke relative to age-matched subjects without stroke (Censor et al, 2016), while other research has found that individuals with stroke, but not age-matched healthy controls, benefit from sleep-based consolidation of a motor task Boyd, 2008, 2009).…”