Brain Simultaneously Encodes Two Speech Streams During Attention Switching

EEG shows brain can simultaneous encode two speech streams

We used EEG to study how the brain handles switching attention between two competing speakers. Our findings reveal that the brain briefly encodes both speech streams at the same time, engaging with the new target before fully disengaging from the old one. This transient overlap, linked to changes in alpha power, suggests listeners reset their lexical context using mechanisms similar to Large Language Models to adapt quickly in complex listening environments.

"Our results indicate asymmetric disengagement and engagement processes during attention switches, where the neural tracking of the new target stream emerges before disengaging from the previous target, revealing a transient simultaneous encoding of two speech streams."