New study reveals brain's predictive mechanism behind focus, hearing

When people focus on a task, the brain doesn't just listen differently -- it listens smarter. A new study from the Hebrew University of Jerusalem shows that the auditory cortex, one of the brain's main sound-processing centres, changes how it operates during active engagement, synchronising its activity to the rhythm of the task rather than merely reacting to sounds.

The research, published in Science Advances, was led by Prof. Israel Nelken from the Edmond and Lily Safra Centre for Brain Sciences and the Institute of Life Sciences.

The findings could help improve hearing aids, attention training, and brain-computer interfaces by revealing how the brain filters and prioritises sound. Devices and therapies that mimic this timing-based mechanism might better detect when a person is focused, suppress background noise, and enhance the clarity of important sounds in real time.

The scientists found that when people perform a task, neurons in the auditory cortex fire in bursts that aren't directly triggered by sound. Each neuron "ticks" at a different moment, marking the passage of the task instead of merely echoing what's heard.

"Our results show that the brain doesn't just react to sounds -- it shapes how they're represented, depending on what we're doing," said Prof. Nelken. "When we're engaged in a task, the auditory cortex listens more efficiently to the sounds that occur in that task."

Until now, scientists knew that attention sharpens how people perceive sound, but not how the brain achieves it. The new study reveals that attention works not by amplifying important sounds, but by reorganising the timing of neural activity to match the structure of the task at hand. This means the auditory cortex doesn't simply boost responses -- it predicts and prepares for expected sounds.

Computer modelling by the researchers showed that this timing-based activity temporarily weakens some neural connections, allowing clearer, more precise responses to sounds that matter for the task. Rather than acting like a volume knob that just increases sound intensity, attention behaves like an adaptive filter, reshaping how neurons communicate.

By uncovering this mechanism, the study offers a fresh view of how the brain makes sense of a complex sensory world. It shows that perception is not passive but predictive--our auditory system is constantly preparing for what it expects to hear next.

"This work helps explain how we can stay focused in noisy environments," Nelken said. "The brain learns to emphasise the sounds that are meaningful for what we're doing and ignore the rest."

The work is based on the doctoral research of Ana Polterovich, with contributions from Alex Kazakov, Maciej M. Jankowski, and Johannes Niediek.