The Madness of Brains™ has been in the news this past week with the Yanny/Laurel effect. Let's use this as a #NeuroThursday peephole into the mysteries of human hearing – via something called the McGurk Effect.
First off, if you haven't dug the Yanny/Laurel thing, there's a great explanation and manipulation up at the New York Times.…
But @mattdoveywriter alerted me today to a better auditory ambiguity! Try listening for the words "Brain Storm." Then replay it, listening for the words "Green Needle."…
YMMV, but for me, it sounds quite clearly like whichever phrase I'm expecting to hear. And longtime #NeuroThursday followers might guess where I'm going with this.
But before I get too far ahead of myself, I want to show you this McGurk Effect thing. If you've taken a psychology course, you may already be familiar with this.
Watch this short (1min) video, with sound on. It's under-explained, but that's a point in its favor. Just compare the sounds in the first three segments.
Okay please do watch that video because the next tweet is gonna be 100% spoilers.
Those first three segments are all the exact same sound - but we hear them differently because of the visual information we get from the dude's mouth movements.
If you rewatch the video with your eyes closed, the effect will disappear – the dude will clearly be saying "ba ba ba" the entire time. (But reopen your eyes, and even spoilers won't eliminate the effect.)
Why is this? Because what we think of as "hearing" isn't purely auditory. As always, our brain gets limited information from the world, and uses expectations & prior knowledge to fill in the gaps.…
In this case, your brain is using visual information to resolve ambiguity in the auditory information. Except that's not quite right, is it? Those sounds aren't ambiguous on their own.
So let's complicate that usual #NeuroThursday lesson of "brain fills in the gaps," and understand that the gaps are there for a reason. Each puzzle piece has funky-shaped edges because it's meant to connect with the other pieces.
Our senses have evolved to work together to solve the challenges of human life – and language is surely forefront among the unique challenges of human brains.
(I have a little pet theory of the Five Things Humans Are Good At, but that's for another week.)
As I've mentioned in the past, every optical (and auditory) illusion is evidence of a successful hack - the brain extrapolating (or interpolating) more information than is directly available.…
A lot of these oddities emerge when we force one system into isolation, when we put someone in a lab, or in front of a screen, or make them listen to voice clips with no accompanying visual info.
(Which is very different from an individual human being blind or deaf. As we say in the old country, But That's Another Thread.)
Separating these senses lets you cut across the grain and see all kinds of fascinating marbling. But from the whole cow's perspective, all that "marbling" is muscle, fat, and function.
The real #NeuroThursday takeaway this time is that laurels, brainstorms, and McGurks all show us the same thing: how we are the result of our evolutionary history, in a multisensory world.
Thanks everyone! If you heard this one clearly, please share it around, and check out some of my other fiction across the internet.
Here's this #NeuroThursday thread about the bigger context of #yannylaurel and auditory illusions, rolled up in Threadreader form:…

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Benjamin C. Kinney (mostly on Bluesky & Mastodon)

Benjamin C. Kinney (mostly on Bluesky & Mastodon) Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @BenCKinney

Aug 13, 2018
Handedness comes in two groups, "right handed" and "not right handed." Most people use their right hands for almost all precision movement, but the other group is a broad spectrum from weakly-right to strongly-left.
The way we describe and define handedness creates the effect @CStuartHardwick rightly notices. Culture defines how we talk about it - but the behavior is mostly genetic. The % of righties has remained constant across continents and milennia.
Hand dominance is a more squirrelly thing than most people realize. For example, righties are better at *some* things with their left hand... and *some* of these asymmetries flip in lefties. Take a few minutes on #LeftHandersDay to learn more!
Read 4 tweets
Aug 8, 2018
Quick heads up on the #BlackSpecFic report: the story counts for @escapepodcast @Pseudopod_org and @PodCastle_org are incomplete, and revisions will be forthcoming.
But you should read and learn from the #BlackSpecFic report anyways! The missing data is due to idiosyncrasies of the @EAPodcasts model, and has no impact on any other magazine's numbers.
Long story short, we treat reprints very differently from other magazines. For @escapepodcast specifically, they were ~45% of our 2017 stories, and our editorial process has one unified pipeline for originals + reprints together.
Read 4 tweets
Jul 23, 2018
Regretting organizing my two Worldcon panels this year. It means I'm not free to throw up my hands in frustration and give up on programming. The last 24hrs have been the last worst icing on a bad cake that's long been baking.
I mean, my panels will be awesome. But if you're skipping programming because you don't trust the con, you've made a sensible choice.
There are always more people who want to be on programming than can fit. There's no way to make everyone happy. I get that. But this weekend's screwups come in the context of a long chain of trust-erosion.
Read 4 tweets
Jul 13, 2018
So glad this one came out! "After Midnight at the Zap Stop" by @ouranosaurus is an awesome story - full of late-night grease, and the luckless & the worthy. But also because it's a #neuroscience teaching opportunity. Might even be a #NeuroThursday!
One offhand line explains a technology as "stimulating a particular set of mirror neurons." Which works as a story element just fine. It sounds plausible and authoritative! But as a neuroscientist, I have strong opinions about #mirrorneurons. I don't think they're real.
To be clear, mine is a controversial opinion. Many neuroscientists would disagree. But it's a hill I'm willing to fight on, especially given how often "mirror neurons" crop up in popular science.
Read 14 tweets
Jul 8, 2018
This Lindsey Sterling + Evanescence concert has been going for 3 minutes and it is already amazing.
Update: she is simultaneously dancing, playing violin, and kicking skeletons.
P.S. She too is a skeleton. Hard to be sure at this distance but I believe she has glittery bones.
Read 14 tweets
Jul 4, 2018
This phenomenon - when you look away from a moving thing, and you briefly see illusory motion in the other direction - is the "Motion Aftereffect," and it comes from some very basic brain maneuvers. Who wants to join me on going full #NeuroThursday here?…
Most neurons in the brain (and elsewhere) do this thing called "adaptation," where they accept whatever's going on as the new normal. For example, if you sit down with your laptop on your lap, you'll soon stop noticing the weight.
This can arise from the crudest single-cell level: some ion channels in the cell membrane have negative feedback loops that self-dampen.
Read 14 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!


0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy


3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!