A team of researchers at 91亚色 has identified that a neural activity contributing to memory consolidation during rest is also observed during attentive visual exploration.
A schematic depicting the sharp-wave ripples (SWR) happening
Sharp-wave ripples (SWRs) are high-frequency brain rhythms that appear during sleep and are thought to train the brain to remember something while it鈥檚 inactive or "offline," essentially working to strengthen memories. However, recent research out of Professor Kari Hoffman鈥檚 Perception & Plasticity Lab indicates SWRs are also associated with attentive focal search.
鈥淲e see it popping up where we didn鈥檛 expect it,鈥 says Hoffman. 鈥淎pparently the brain uses this signal even while it鈥檚 working hard to learn solutions to new problems, and not just when it鈥檚 offline or at rest.鈥
Kari Hoffman
Several labs have performed experiments to interrupt these ripples during sleep and inactivity, and have found that interruptions lead to memory deficits. This, says Hoffman, suggests that SWRs are causally related to memory formation.
The ripples, she says, are considered the most synchronous activity in the healthy brain and their rhythm is most closely linked to memory formation.
The new findings out of Hoffman鈥檚 lab suggest SWRs may have a similar effect on memory consolidation during active learning, and not just at rest, and therefore could play a new role in memory formation.
Subjects are given a goal-oriented visual search task, similar to the game 鈥淲here鈥檚 Waldo.鈥 If a ripple happens near the visual target object, the likelihood of finding that object increases.
The work is in the Journal of Neuroscience, and the first author is Timothy Leonard, a 91亚色 PhD student in psychology and a recipient of a聽Queen Elizabeth II Graduate Scholarship in Science & Technology.
鈥淚n the context of ongoing deep brain stimulation clinical trials to alleviate memory decline, this may be an important signal to consider during learning and remembering, and not just while we're sleeping,鈥 says Hoffman.
The results from the study will also be applied to the lab鈥檚 Brain Canada-funded neurorehabilitation research, and researchers will look at the SWR activity in healthy participants and memory-impaired participants during the same tasks.
The goal is to 鈥渂etter understand how memory formation works, in the hope of creating better improving treatments to fight memory decline,鈥 says Hoffman.
The research will continue at the lab with a focus on a real-time closed-loop interruption to see if it has an effect, or a different effect, on active search versus rest.
By Ashley Goodfellow Craig, YFile deputy editor