Scientists discover how the brain anticipates future events by encoding past experiences

A new study published in Nature has revealed key insights into how our brain cells help us learn from experience and predict what might happen next. The research on individuals undergoing clinical procedures focused on the hippocampus and entorhinal cortex—brain regions crucial for memory and learning.

“The ability to recognize patterns and predict future events is a fundamental part of how humans learn,” says Dr Pawel Tacikowski, the lead author of the publication, who now works at the Coimbra Institute for Biomedical Imaging and Translational Research, Coimbra University.

Previous studies have relied on neuroimaging techniques like fMRI to study how these processes occur in the brain. However, these methods don't provide a direct view of how individual neurons contribute to this function. In this groundbreaking study, researchers were able to record the activity of single neurons in real-time, shedding new light on the brain’s inner workings.

The participants were shown a series of images in a specific sequence but weren’t told to memorize or predict anything. Remarkably, the neurons in their hippocampus and entorhinal cortex gradually adjusted their activity to reflect the underlying pattern. This means that the brain was able to learn the sequence structure implicitly, forming a mental map of when and what would happen next.

Additionally, the researchers observed that neurons "replayed" their activity in a time-compressed form, representing previously learned sequences. This replay activity, happening spontaneously during study breaks, is thought to be how the brain consolidates learning and reinforces its ability to predict future events.

These findings offer a new understanding of how our brains encode and remember the flow of events in our lives, combining information about "what" happens and "when" it happens to make better predictions about future events.

“We're excited about this study because understanding how the brain organizes events in time could have important clinical applications. For example, future memory-enhancement therapies might focus on boosting specific neuronal activity that represents important memories” adds Dr Tacikowski.

In addition to first author Pawel Tacikowski, the study was co-authored by researchers Güldamla Kalender, Davide Ciliberti and Itzhak Fried. The research was conducted at the University of California, Los Angeles (Department of Neurosurgery), Karolinska Institute (Department of Neuroscience) and the University of Coimbra (Coimbra Institute for Biomedical Imaging and Translational Research).

The scientific article “Human hippocampal and entorhinal neurons encode the temporal structure of experience” is available here.