Scientists Unveil How Precise Timing of Nerve Signals Shapes Brain Information Processing

Researchers have long known that our brain favors processing information we focus on, a phenomenon illustrated by the so-called cocktail party effect.

"In crowded environments with voices, music, and background noise, the brain can zero in on a single conversation. While other sounds are still present, they become peripheral at that moment," explains Dr. Eric Drebitz, a neuroscientist from University Bremen.

The brain concentrates its resources on the most relevant information—like a specific voice while filtering out less important signals.

"Previously, it was unclear how this crucial mechanism of selecting pertinent information functions. For example, when crossing the street and spotting an incoming car, our brain instantly prioritizes processing that visual input," says Drebitz.

"Other sensory inputs, like signs or pedestrians, become less noticeable as they divert attention and delay response time. It's this targeted focus allowing us to react swiftly in critical situations."

A team led by neuroscientists Andreas Kreiter and Eric Drebitz has now shown for the first time how the brain transmits and processes significant information. Their findings are detailed in Nature Communications.

"Critical to whether a signal gets processed further depends on when it arrives—during brief cycles of heightened cellular sensitivity," clarifies Drebitz.

"Nerve cells operate cycling between periods of high and low activity. They're most receptive near the peak of their active phase, making signals timed just before this peak more effective."

This temporal coordination forms the foundation for brain information processing. Attention leverages this by aligning nerve cell cycles to receive vital signals during optimal timing.

The study conducted on rhesus monkeys—whom share a similar cortical organization with humans—proved this mechanism by examining selective signal transmission through visual tasks.

Researchers inserted weak electrical stimuli into an early section of the visual pathway (area V2), which didn't relate to the task and acted solely as test indicators. They observed effects on downstream area V4 activity.

"A signal modified neuronal activity in V4 only if timed correctly within the receptive phase. Misaligned signals, arriving too early or late, were ineffective," explains Drebitz.

"When the artificial signal landed during this sensitive window, not only did it change neuron behavior, but also influenced animal response times and accuracy—indicating the test signal integrated into processing even though it wasn't relevant to the task."

"These results support creating more precise brain models, showing how information is prioritized before affecting perception, learning, and behavior," concludes Drebitz.

The knowledge also has implications beyond foundational research. "Conditions like Alzheimer's and ADHD involve issues with processing and storing pertinent information. Additionally, brain-computer interfaces and AI systems could benefit from understanding these principles for more reliable communication."