Our brain ‘swivels’ to focus on sounds from different directions

Animals such as dogs, cats, and deer can move their ears to focus on certain sounds. Humans lost this capability around 25 million years ago, but recent research reveals that we have developed an advanced ability within our brains to selectively direct auditory attention.

This novel study employed mobile electroencephalography (EEG) devices to capture electrical brain activity in participants while they were in motion. Historically, EEG was limited to stationary lab settings, requiring wired connections to a computer. However, the advent of smaller, wireless setups has opened the door to measuring brain activity in dynamic environments, allowing researchers to link behavioral changes with brain function.

Findings suggest that movement significantly impacts brain operation. “Active exploration enhances perception, facilitates spatial navigation, and integrates multisensory information into an effective understanding of the environment,” explains Maren Schmidt-Kassow from Goethe University in Frankfurt, who did not participate in this study. “Cognition is fundamentally linked to physical activity.”

Previous research from Barbara Haendel’s team at the University of Wurzburg indicated that walking influences visual processing, making individuals more aware of peripheral objects, typically ignored when stationary. The latest findings show a similar auditory focus: the brain continually tweaks its attention towards sounds based on the listener’s movement.

In their experiment, 35 participants donned mobile EEG and motion sensors while walking in a figure-of-eight path, listening to a continuous audio stream through headphones. The EEG data indicated that sound processing significantly increased when participants moved along the path compared to when they were stationary. When taking turns, the brain would further prioritize sounds from that direction, akin to panning between stereo speakers or physically orienting an ear toward the sound.

Research team member Liyu Cao from Zhejiang University proposes that this internal auditory adjustment may have evolved as a safety mechanism, facilitating quicker responses and safer navigation in evolving environments.

This groundbreaking research holds promise for improving navigation tools for visually impaired individuals and enhancing hearing aids to better filter background noise based on the wearer’s movement direction, as noted by Haendel.

Additionally, it may shed light on why exercising outdoors yields superior cognitive benefits compared to indoor activities like treadmill running or stationary cycling. “Movement encompasses more than just muscular activity,” says Haendel. “The way you move affects brain function and vice versa; this intricate relationship has evolved for optimal efficiency.”