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  • Mind reading?

  • Of course not.

  • I love reading.

  • Look, mind reading might sound like pseudoscientific--

  • pardon my language--

  • bullshoot.

  • But its scientific counterpart, thought identification,

  • is very much a real thing.

  • It's based in neuroimaging and machine learning,

  • and what's really cool is that experiments in mind reading

  • aren't just about spying on what someone is thinking.

  • They're about figuring out what thoughts are even made of.

  • I mean, when I think of something,

  • what does that mental picture actually look like?

  • What resolution is it in?

  • How high fidelity is a memory,

  • and how do they change over time?

  • Well, in this episode,

  • I'm going to look at how reading people's minds

  • can help us answer these questions.

  • My journey begins right here at the University of Oregon.

  • I'm meeting with Dr. Brice Kuhl from the Kuhl lab.

  • He's a neuroscientist who uses neuroimaging

  • and machine learning to figure out what people are thinking

  • without them telling him.

  • So tell me what you're doing here.

  • Well, I'm in the cognitive neuroscience program here,

  • and I study human memory.

  • My lab primarily uses neuroimaging methods,

  • so we do a lot of work using

  • functional magnetic resonance imaging,

  • or fMRI.

  • And how do you use fMRI to investigate memories?

  • We're looking at the pattern of neural activity.

  • When you form a memory, there's a certain pattern.

  • And we can record that pattern

  • and then test whether that pattern is reinstated

  • or reactivated at a later point, like when you're remembering it.

  • Does that mean we can look at the patterns of brain activity

  • and deduce what it is that is being remembered, or recalled,

  • or even just thought?

  • Yes, and so we call that decoding.

  • So it basically takes your input pattern

  • as some pattern of activity that we record

  • while you're remembering something.

  • And we make a prediction about what you're remembering.

  • You can see how this sounds like mind reading.

  • [laughs] Yes. It sounds like that.

  • So, Brice, what are you going to do to me today?

  • So, what we're going to be doing today

  • is uncharted territory for us.

  • So we're going to be trying out a kind of new variant

  • of the experiment on you.

  • So I can't guarantee any particular results.

  • But it represents where the field is

  • and where we're trying to go.

  • Today, you're going to participate in an experiment

  • where you'll be studying faces.

  • So we're going to have you study

  • 12 pictures of celebrities.

  • People I already am familiar with.

  • -People that you know, yeah. -Okay.

  • And you're going to try to remember those pictures.

  • Then we're going to have you go into the MRI scanner.

  • Try to bring that picture to mind as vividly as possible.

  • And we're going to be recording your brain activity

  • as you try to imagine these pictures.

  • We're going to try to build the face.

  • Essentially draw a picture of what you're remembering.

  • -A picture? -A picture.

  • An actual picture that we can print out

  • and I could, like, hang on my wall.

  • [laughs] If you wanted.

  • [Michael] The first step is for me to memorize

  • the 12 specific celebrity photographs

  • Brice will later try to detect me thinking about.

  • I sat down to do this graduate student, Max.

  • The success of his predictions depend, in part,

  • on my ability to recall these faces

  • as vividly as possible while inside the fMRI.

  • All right, so...

  • [sighs]

  • I think I have a pretty good memory of all of those.

  • -Great. -I feel the stakes are high.

  • With the celebrity faces hopefully memorized,

  • it's time for the next step:

  • going through the metal detector

  • and into the fMRI,

  • where Brice will record and monitor my brain activity,

  • and then later feed it into his algorithm to rebuild the faces.

  • This will be the first time he's attempted

  • to reconstruct faces from long-term memory,

  • which is very difficult, because we're relying

  • on how clearly I can remember the celebrity photos

  • I saw an hour ago.

  • I love its eyes. Look at that.

  • [woman]

  • Wouldn't the kid be like, "It's going to eat me"?

  • An fMRI monitors the activity within the brain

  • by dividing it up into thousands of small cubes

  • called voxels, or volumetric pixels.

  • Each of these voxels contains

  • hundreds of thousands of neurons.

  • Using fMRI, we are able to detect

  • blood flow within these voxels,

  • which means that that part of the brain is active.

  • If I'm shown several pictures of people with mustaches,

  • my brain will react to the features for each face.

  • But there will be a common area of my brain

  • that is engaged throughout.

  • That may be the area of my brain that reacts to mustaches.

  • So later, when I imagine a face,

  • if Brice notices that area is engaged,

  • he can predict that I am thinking

  • about a mustache.

  • So right now Michael's in the scanner,

  • and he's seeing words appear on the screen one at a time,

  • and he's trying to visualize the face,

  • remember the face in as much detail as possible.

  • What you can see here are the images that we're acquiring.

  • We get one of these brain volumes every two seconds.

  • So these are refreshing in real time as we collect the images.

  • [Michael] With part one of the fMRI session over,

  • it's time for part two, where Brice and his team

  • will learn the language of my brain activity,

  • so they can later decode by brain scans.

  • Hi, Michael. You doing okay still?

  • [Michael] Yup.

  • They'll show me hundreds of unique faces,

  • and record how my brain reacts

  • to certain facial characteristics.

  • They will then use this information

  • to reconstruct the celebrity faces

  • I thought about during the first phase of the scan.

  • Really, the more faces that we can show Michael, the better.

  • So we're going to basically keep him in there

  • as long as he's comfortable.

  • [Michael] Two hours was the maximum time

  • we could get in the fMRI.

  • But I was able to look at over 400 faces,

  • which should be enough to get

  • some pretty interesting results.

  • Hey, Michael, you did it. That was great.

  • We're going to come get you out.

  • [Michael] All right.

  • Yeah, so these just show some of the pictures

  • that we were taking while you were in there.

  • Some images of your brain.

  • Now we are going to crunch some numbers.

  • Max is going to analyze your data.

  • We'll meet up again tomorrow,

  • where we'll look at the results,

  • where we try to actually reconstruct the face images

  • from the brain data that we just collected.

  • All right. Well, see you tomorrow.

  • All right. Thanks a lot.

  • Max, thank you as well. I can't wait.

  • You better pull an all-nighter.

  • I want this data to be perfect.

  • All right, so I am back at Dr. Kuhl's lab.

  • Overnight, his team crunched the data,

  • and I can't wait to see what they think they saw me thinking.

  • How are my results?

  • I think they look good.

  • We're going to take a look in just a moment here.

  • All right, I can't wait.

  • -So can I just take a seat? -Yeah, have a seat.

  • All right, so...

  • first of all...

  • what am I seeing? Oh, okay, well,

  • these are the pictures I actually memorized.

  • -That's right. -And this is what

  • you've reconstructed from my imagination.

  • -That's right. -Oh, wow. Okay.

  • [Brice] Okay, so this is one of the reconstructions

  • that was generated.

  • [Michael] Interesting.

  • [Max] So that's John Cho.

  • [Michael] Not bad. Not bad.

  • -Can we see the side by side? -Yeah.

  • [Michael] I see, you know, similarities

  • in the kind of facial expressions in general.

  • You know, you could almost see the hairline matching here.

  • The shape of the face I also thought was--

  • It kind of had a square shape to it.

  • -Yes. Yes. -So those are the things

  • that came out to me.

  • And so when I was visualizing

  • this image of John Cho,

  • the squareness of the face was the first, most salient thing.

  • I just kept thinking, he was the square guy.

  • Excellent, all right.

  • [Brice] So that's Megan Fox.

  • [Michael] Mm-hmm.

  • You're going to show us the-- side by side.

  • [Michael] The side by side. Right.

  • [Brice] You can see the picture you actually saw,

  • and that's the reconstruction we generated.

  • I'll you this. Megan Fox, I was not able

  • to have a really clear picture in my mind.

  • For some reason, this image of her was really hard for me

  • to bring back into my mind.

  • The sternness in the face was something that I did pick up on.

  • So I did sense that there was-- It looked feminine.

  • And you picked up on the sternness.

  • And so together, that produces a match.

  • [Michael] Keep in mind that Brice and his team

  • have read these from my memory.

  • But when I remember a face,

  • do I picture every detail simultaneously

  • with photographic accuracy?

  • Or do I just attend to a few at a time?

  • By reading my mind, they may be seeing

  • how bad my memory is, and how it works.

  • -Me! Me! -[Brice laughs]

  • Okay, so that is your reconstruction

  • of me thinking about this image of myself.

  • [Brice] That's right.

  • Where'd the beard go?

  • [Brice] I don't know. I was hoping you could tell me.

  • [Michael] For instance, this is a picture of me remembering my own face.

  • It really doesn't look like me, but the question is:

  • how good am I at picturing myself?

  • I don't think of my own face that often,

  • so the strangeness in the result

  • may be as much about flaws in my own memory

  • and mental picture of myself as flaws in the technology.

  • So that's Jennifer Lawrence, I believe.

  • [Michael] That's Jennifer Lawrence?

  • It looks like it's Jennifer Lawrence's much older uncle.

  • [all chuckle]

  • Nothing here was too mind-blowingly close.

  • But this is something that you're just starting out trying

  • these sort of long-term memories.

  • What Brice and his team read in my mind

  • might have been more accurate if they'd shown me thousands

  • rather than hundreds of images in the fMRI,

  • because then the algorithm would have learned

  • the language of my brain more thoroughly.

  • But regardless, the quality of my memories

  • would have still been an issue.

  • I mean, look what happens when memory

  • is cut out of the equation entirely.

  • Brice also read my brain activity

  • when I was looking at faces in the fMRI.

  • not just imagining them.

  • And those results were much closer

  • than those reconstructed from my memory.

  • Okay, so, what am I looking at right here?