New discovery – brain waves that coordinate formation of human memories 20 October 2021 – Posted in: news – Tags: 2021, biomedical engineering, Brain, Cagdas Topcu, ECoG, iEEG, Journal, Mayo Clinic, Michal Kucewicz, michal lech, NeuroImage, Neuroscience, new paper, paper, PhD, Tory Marks, Verbal
We are delighted to share with you about the recent publication of our research findings, which appeared this month in the journal NeuroImage. It is a result of almost 4 years of our work on mapping the brain waves generated in our brain as memories for words are formed. Tory Marks, a PhD student of biomedical engineering at Mayo Clinic, worked together with other members of our BME lab on a large dataset of over 150 epilepsy patients who performed a simple task to remember lists of common nouns for subsequent free recall. As the patients were remembering these word lists, Tory analyzed the brain wave activities with unprecedented detail of their characteristic frequency (theta, alpha, beta, gamma rhythms), phase of forming memories (attention before and encoding after word presentation), and locations in the brain to produce a five-dimensional map (3 space, time and spectral frequency) of what happens when we remember words.
The big picture that we obtained from this mapping of memory formation was pretty complex, as would be expected for a higher brain function like this. Various brain waves of particular frequencies were observed in multiple, discrete areas of the cortex at particular phases of remembering. Overall, the low (theta), the intermediate (alpha and beta), and the high (gamma) frequency waves were mapped in different cortical locations and at distinct times. What it practically means is every little bit of the brain generates brain waves at a characteristic frequency and time – we call these ‘spectral fingerprints’. These fingerprints could be selectively targeted to improve memory functions with, e.g. local electrical stimulation. We still need to know how each fingerprint is involved in memory processing, but at least we now have a comprehensive map of their dynamics in the human brain.
If you want to see a pretty visualization of these brain waves as memories are formed, then you can play a video available as part of the open-access article on the journal website below. You don’t have to be a scientist to appreciate how a mosaic of colorful waves is moving from the visual areas in the back of your brain to the language and executive centers under your forehead as new words are remembered!