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.
- NalNezumi
Related, but this reminds me of the story by Richard Feynman [1] when he practices counting up to 60 seconds in his head, and after many experiments around what he can do simultaneously conclude that he can simultaneously count and read but not speak. Later sharing this to John Tukey, he's told that Tukey can't read while counting but could speak while counting.
Turns out Tukey is visualizing looking at a tape, while he counts, while Feynman imagined himself talking to himself, so he couldn't speak while counting but Tukey couldn't read while counting
>By that experience Tukey and I discovered that what goes on in different people's heads. when they think they're doing the same thing - something as simple as counting - is different for
different people. And we discovered that you
can externally and objectively test how the brain works: you don't have to ask a person how he
counts and rely on his ownobservations of him-self; instead, you observe what he can and can't do while he counts. The test is absolute.
There's no way to beat it; no way to fake it.
>It's natural to explain an idea in terms of
what you already have in your head. Concepts
are piled on top of each other; this idea is taught
in terms of that idea, and that idea is taught in
terms of another idea, which comes from count-
ing, which can be so different for different
people!
>I often think about that, especially when I'm
teaching some esoteric technique such as integrat-
ing Bessel functions. When I se […]
- a_gopher
If reading aloud a children story, you may notice you are able to maintain an independent unrelated train of thought. While doing so, I notice that occasionally extra mistakes can "leak" into the story telling - e.g. you read a single word incorrectly, maybe substituting a word from your other train of thought.
- subhro
As a pilot and a radio officer, I have always been able to process and service 2 audio streams simultaneously. So not surprised with this finding.
- lokimedes
Many mindfulness practices seem to direct attention at two place at once, to quiet the inner voice. Perhaps this relates to more than just speech, but to attention itself. George Gurdjieff's "The Fourth Way" deals with self remembering, and his pupil, P. D. Ouspensky, has a very vivid description in [1] of how focusing on two things at once leads to a changed state of consciousness, that seems like meditation, and comes from the saturation of the two streams of attention.
[1] https://en.wikipedia.org/wiki/In_Search_of_the_Miraculous
- DrScientist
If you couldn't process multiple streams ( audio/visual/other senses ) how would you ever be able to monitor the background for danger and context switch?
There is a difference between conscious experience and what's going on in the background.
- pxc
When I used to go to parties in college, I was known within my friend group for participating in multiple conversations at once, flitting from one group to another. One of my friends later told me he thought it was impressive, but in fact I just couldn't help but hear all of the conversations at once, and if multiple groups were talking about interesting things, I would find myself torn between them, and end up bouncing back and forth.
- ChrisRR
I had assumed this was already well known.
My issue is that I can't stop processing other speech streams. It seems other people can tune out conversations around them when talking to a person but I have to hear every word
- chrisbrandow
Famously, the Apollo Mission control team learned to handle multiple conversations stream simultaneously. The side effect was that going to cocktail parties was a nightmare, because they couldn’t turn it off.