Reactivation of specific memories can indirectly strengthen related ones, study finds

Most humans can recall specific events and past experiences for long periods of time. This capability, referred to as episodic memory, is known to be in great part supported by the activity of neurons in the hippocampus and medial temporal lobe.

Past neuroscience and psychology studies consistently found that episodic memory is associative. This essentially means that remembering one past event, for instance a graduation, can in many cases prompt people to also remember other related events, such as a party that celebrated the graduation.

Researchers at Biología Molecular y Neurociencias (IFIByNE)-CONICET and the University of Buenos Aires recently carried out a new study exploring the possibility that the reactivation of specific episodic memories does not only help to strengthen those memories, but also the memories of other related events or experiences.

Their findings, published in Communications Psychology, suggest that consolidated episodic memories can also be indirectly strengthened when people are remembering other events that are contextually bound to these memories.

“Memory reactivation has been shown to strengthen reactivated memories, but its effects on related, non-reactivated memories remain unclear,” wrote Juan Cruz Beron, Luz Bavassi and their colleagues in their paper. “This study investigated whether reactivation of a consolidated target memory could indirectly enhance the retention of peripheral information acquired in the same context.”

Most previous studies investigating the activation of related memories specifically focused on memories that have not yet been consolidated, which essentially means that they are relatively new and have not been stabilized in the brain for long-term storage. In contrast, Beron, Bavassi and their colleagues wanted to determine whether memories that are already consolidated can be strengthened further when people are recalling contextually related memories.

“We hypothesized that reactivating a consolidated target memory would improve its retention and strengthen contextually associated memories,” wrote the researchers. “To test this, we conducted four experiments in which participants first learned face-name pairs (target memory) alongside everyday objects (peripheral memory).”

The researchers carried out a four-day experiment involving a total of 238 adult participants. On the first day, all participants were asked to learn associations between faces and names, as well as a set of everyday objects.

On day 2, a subset of the participants completed a task that was designed to reactivate the memories they made the day before, by presenting them with incomplete reminders of these memories. Simultaneously, the rest of the participants performed an unrelated control task.

On the third day, the researchers assessed the ability of both subsets of participants to remember both the target (i.e., face-name pairs) and peripheral (objects) information memorized during the first stage of the experiment. Notably, they found that people who were in the memory re-activation condition on day 2 of the experiment remembered both the types of stimuli better than those in the control condition.

“Results revealed that reactivation significantly improved the retention of target and peripheral memories when acquired in the same context,” wrote the researchers. “However, when peripheral memories were learned in a different context, reactivation of the target memory did not produce the same indirect strengthening effect.

“These findings suggest that the indirect strengthening of consolidated memories through reactivation is context-dependent and may rely on the shared spatiotemporal acquisition context.”

Overall, the findings of this recent study offer new valuable insight into the mechanisms of episodic memory re-activation. This insight could inspire other research groups to investigate the newly unveiled re-activation mechanisms, which could further improve our understanding of human memory processes.

© 2025 Science X Network

Most humans can recall specific events and past experiences for long periods of time. This capability, referred to as episodic memory, is known to be in great part supported by the activity of neurons in the hippocampus and medial temporal lobe.

Past neuroscience and psychology studies consistently found that episodic memory is associative. This essentially means that remembering one past event, for instance a graduation, can in many cases prompt people to also remember other related events, such as a party that celebrated the graduation.

Researchers at Biología Molecular y Neurociencias (IFIByNE)-CONICET and the University of Buenos Aires recently carried out a new study exploring the possibility that the reactivation of specific episodic memories does not only help to strengthen those memories, but also the memories of other related events or experiences.

Their findings, published in Communications Psychology, suggest that consolidated episodic memories can also be indirectly strengthened when people are remembering other events that are contextually bound to these memories.

“Memory reactivation has been shown to strengthen reactivated memories, but its effects on related, non-reactivated memories remain unclear,” wrote Juan Cruz Beron, Luz Bavassi and their colleagues in their paper. “This study investigated whether reactivation of a consolidated target memory could indirectly enhance the retention of peripheral information acquired in the same context.”

Most previous studies investigating the activation of related memories specifically focused on memories that have not yet been consolidated, which essentially means that they are relatively new and have not been stabilized in the brain for long-term storage. In contrast, Beron, Bavassi and their colleagues wanted to determine whether memories that are already consolidated can be strengthened further when people are recalling contextually related memories.

“We hypothesized that reactivating a consolidated target memory would improve its retention and strengthen contextually associated memories,” wrote the researchers. “To test this, we conducted four experiments in which participants first learned face-name pairs (target memory) alongside everyday objects (peripheral memory).”

The researchers carried out a four-day experiment involving a total of 238 adult participants. On the first day, all participants were asked to learn associations between faces and names, as well as a set of everyday objects.

On day 2, a subset of the participants completed a task that was designed to reactivate the memories they made the day before, by presenting them with incomplete reminders of these memories. Simultaneously, the rest of the participants performed an unrelated control task.

On the third day, the researchers assessed the ability of both subsets of participants to remember both the target (i.e., face-name pairs) and peripheral (objects) information memorized during the first stage of the experiment. Notably, they found that people who were in the memory re-activation condition on day 2 of the experiment remembered both the types of stimuli better than those in the control condition.

“Results revealed that reactivation significantly improved the retention of target and peripheral memories when acquired in the same context,” wrote the researchers. “However, when peripheral memories were learned in a different context, reactivation of the target memory did not produce the same indirect strengthening effect.

“These findings suggest that the indirect strengthening of consolidated memories through reactivation is context-dependent and may rely on the shared spatiotemporal acquisition context.”

Overall, the findings of this recent study offer new valuable insight into the mechanisms of episodic memory re-activation. This insight could inspire other research groups to investigate the newly unveiled re-activation mechanisms, which could further improve our understanding of human memory processes.

© 2025 Science X Network