Ripple Activity In The Brain Helps Organize And Store Episodic Memories

8 hours ago

A investigation squad from nan Faculty of Psychology astatine nan University of Barcelona, nan UB Institute of Neurosciences (UBneuro) and nan Bellvitge Biomedical Research Institute (IDIBELL) has identified, for nan first clip successful humans, and successful a realistic environment, a cardinal neurophysiological system successful representation formation: ripple-type encephalon waves —high-frequency electrical oscillations that people and shape nan different episodes aliases fragments of accusation that nan encephalon stores arsenic memories. These findings, published successful nan diary Nature Communications, deepen our knowing of really representation is organized successful nan quality encephalon and unfastened up caller avenues for addressing disorders related to representation impairment.

The study is led by Lluís Fuentemilla, a interrogator astatine nan IDIBELL and UBneuro Cognition and Brain Plasticity investigation group, and is portion of nan doctoral thesis carried retired successful this aforesaid group by Marta Silva, nan article's first author, who is presently astatine Columbia University (United States). Experts from nan Epilepsy Unit astatine Hospital Clínic de Barcelona - August Pi one Sunyer Biomedical Research Institute (IDIBAPS), Columbia University, Ruhr University Bochum and Ludwig Maximilian University of Munich (Germany) besides participated successful nan study.

The recollection of circumstantial episodes is nan ground of memory. Although acquisition is constant, location is grounds that nan encephalon segments it erstwhile location are changes successful nan travel of accusation to person it into memories.

These segments people nan constituent astatine which nan encephalon closes 1 section successful representation and originates signaling another. For example, erstwhile you are doing thing and you person a telephone telephone aliases nan doorbell rings, nan encephalon identifies that location has been a alteration successful nan people of nan acquisition and uses these events arsenic if they were punctuation marks, a afloat extremity successful a sentence, to proceed to shop what you were doing successful nan shape of an episode."

Lluís Fuentemilla, interrogator astatine nan IDIBELL

Previous studies successful mice person indicated that ripples play a basal domiciled successful representation formation. "These waves are thought to coordinate accusation transportation betwixt nan hippocampus and neocortical regions — nan temporal and frontal cortex — helping to merge caller memories. This neural awesome is cardinal to generating synaptic potentiation, allowing nan encephalon to hole and consolidate a memory", statement nan researchers.

A pioneering experiment

Although these signals person been extensively studied successful animals, particularly mice, their study successful humans has been very limited. This is owed to nan trouble of signaling them, arsenic they originate successful encephalon areas that require nan usage of intracranial electrodes. In this study, however, researchers person managed to analyse these waves successful a naturalistic context, i.e. successful conditions adjacent to mundane life. To execute this, they recorded nan intracranial electrophysiological activity of 10 patients pinch epilepsy — who had undergone room for objective reasons — while they watched nan first section of nan BBC series Sherlock, which lasts 50 minutes. "This type of communicative format, arsenic successful existent life, features segment changes that nan encephalon identifies arsenic arena boundaries. The participants were past asked to callback and recount what they remembered of nan plot", nan authors explain.

The results showed a move shape of ripple activity activation during representation encoding. "We observed that these waves occurred successful some nan hippocampus and neocortical areas. However, they followed a different temporal rhythm: successful nan hippocampus, ripple activity accrued astatine nan boundaries of events, reflecting their domiciled successful segmentation; successful contrast, successful cortical regions, their beingness was higher during nan soul improvement of events", says Marta Silva.

According to nan researchers, this shape suggests coordination betwixt nan 2 encephalon structures, arsenic if they were "an orchestra": nan neocortical regions actively process information, and nan hippocampus kicks successful erstwhile location is simply a alteration of segment to "pack and consolidate" nan memory.

Segmenting to remember

These findings reenforce nan thought of nan value of segmentation and structuring successful representation formation. "What we see, some successful this study and successful related work, is that it is not capable to salary attraction and grounds information, but that it is arsenic aliases much important to shape it successful nan discourse of nan changeless travel of information. In different words, it is not conscionable a matter of activating nan brain's machinery while it is signaling information, but besides of acting arsenic an orchestra conductor who marks erstwhile nan representation originates and ends. These signals thief not only to grounds what is happening arsenic it happens, but besides to shape nan accusation coherently", they constituent out.

The results could besides person important implications for knowing representation disorders and processing early therapeutic interventions. "To date, erstwhile faced pinch an amnesic problem, we thought of attraction deficits aliases difficulties successful acquiring information. Our results propose that location could besides beryllium a nonaccomplishment successful these segmentation signals, successful really accusation is system successful nan brain", they note.

In this sense, nan study opens nan doorway to exploring therapies that see really accusation is organized astatine nan encephalon level. "In older people, for example, who are opening to show representation impairment, it could beryllium beneficial to coming accusation successful a much system way, pinch clear pauses betwixt applicable events. Not only arsenic a matter of cognitive rhythm, but because this could facilitate its correct encoding and storage", they conclude.

Source:

Journal reference:

Silva, M., et al. (2025). Movie-watching evokes ripple-like activity wrong events and astatine arena boundaries. Nature Communications. doi.org/10.1038/s41467-025-60788-0.