Recent quotes:

Brain ripples may help bind information across the human cortex: Ubiquitous bursts of brain waves appear to synchronize disparate and distant elements of memory, unifying them upon recollection -- ScienceDaily

The UC San Diego team, led by Halgren, found that ripples also occur in all areas of the human cortex, in waking as well as sleep. The ripples were brief, lasting roughly one-tenth of a second, and had a consistent narrow frequency close to 90 cycles per second. The authors calculated that a typical brief ripple event may involve approximately 5,000 small modules becoming active simultaneously, distributed across the cortical surface. This work is part of the doctoral thesis in neurosciences by first author Charles W. Dickey. "Remarkably, the ripples co-occurred and synchronized across all lobes and between both hemispheres, even at long distances," said Dickey. "Cortical neurons increased firing during ripples, at the ripple rhythm, potentially supporting interaction between distant locations. "There were more co-occurrences preceding successful memory recall. All of which suggests that distributed, cortical co-ripples promote the integration of different elements that may comprise a particular experiential memory."

Neurons ripple while brains rest to lock in memories: How quiet minds encode spatial maps while 'introspecting' -- ScienceDaily

"Animals encode a memory of an environment as they run around," said Kemere, an assistant professor of electrical and computer engineering who specializes in neuroscience. "They form a spatial map as individual neurons are activated in different places. When they're awake in our experiments, they're probably doing that exploration process 40 to 60 percent of the time. "But for the other 40 percent, they're scratching themselves, or they're eating, or they're sort of snoozing," he said. "They're not asleep, but they're paused; I like to call it introspecting." Those periods of introspection provided the critical data for the study that inverted the usual process of matching brain activity to movement while the animals were active. The primary data was gathered over the course of many experiments under the direction of Diba, an associate professor and leader of the Neural Circuits and Memory Lab at Michigan Medicine. As the animals explored either back-and-forth tracks or maze-like environments, electrodes in their brains sensed sharp wave-associated bursts of neural activity called population burst events (PBEs). In these events, between 50,000 and 100,000 neurons all fire within 100 milliseconds and send ripples throughout the brain that are not yet fully understood.