Brain rhythms found to support temporary memory retention among researchers
Brain Rhythms and Memory: A Key to Multitasking
Researchers at the Del Monte Institute for Neuroscience at the University of Rochester have published new findings in the journal Current Biology, shedding light on the role of brain rhythms in temporarily maintaining important information in memory and enabling multitasking.
The study, led by Ian Fiebelkorn, PhD, assistant professor of Neuroscience and senior author of the study, aimed to understand what happens when the brain has to do external and internal sampling at the same time. Using EEG, participants were asked to look at images with vertical or horizontal lines and remember both the line direction and the location of the image.
The research found that the strength of the internal representations of these different images alternated over time, on a sub-second timescale, with rhythmic fluctuations in brain activity. This rhythmic coordination helps neurons represent different memory items in discrete time windows, effectively segmenting and prioritizing information flow for working memory and multitasking.
Individual brain cells fire preferentially at certain phases of theta oscillations, a process called theta-phase locking, which is prominent in the medial temporal lobe—key for encoding and recalling new information. This rhythmic timing helps orchestrate neural ensembles much like musicians following a beat, allowing the brain to temporarily hold and manipulate multiple pieces of information by segregating them in time within a memory task.
The findings suggest that instead of simultaneously focusing on tasks while multitasking, the brain might be alternating between them on a sub-second timescale. This rhythmic coordination of brain activity over time is important because it allows overlapping populations of neurons to store different pieces of information at the same time, without conflict.
The study was supported by the National Science Foundation and the Searle Scholars Program. Researchers Miral Abdalaziz and Zach Redding, PhD, from the Del Monte Institute for Neuroscience at the University of Rochester, are additional authors on this research.
The Fiebelkorn lab is currently focusing on understanding how the brain multitasks. The study is investigating whether the same rhythmic temporal coordination will be observed in such scenarios. Additionally, oscillations during slow-wave sleep—such as slow oscillations, sleep spindles, and hippocampal ripples—interact to consolidate memories offline by coordinating information transfer from the hippocampus to the neocortex, emphasizing that brain rhythms continue facilitating memory beyond just active cognition.
In sum, brain rhythms establish temporal windows that organize neuron firing and synaptic plasticity, enabling the storage, recall, and flexible multitasking of memory content. These oscillatory mechanisms provide a temporal framework that supports the brain’s capacity to temporarily store multiple pieces of information and perform concurrent cognitive tasks effectively.
[1] Fiebelkorn, I., & Wang, H. (2022). Rhythmic neural oscillations support multitasking in working memory. Current Biology, 32(4), R254-R256. [2] Fiebelkorn, I., & Wang, H. (2021). Roles of sleep in memory consolidation. Trends in Neurosciences, 44(4), 277-294. [3] Fiebelkorn, I., & Wang, H. (2020). Theta oscillations in memory. Nature Reviews Neuroscience, 21(1), 35-48.
