Hacker News Reader

Comment by swayvil | Hacker News Reader

This kind of brain-reading certainly seems to be in the same general species as lie detection.

So it must exist. An AI device that takes a thousand data points off your brain and tells you lie or not.

What would we do if we had a ~100% accurate lie detector? How would that go down, socially?

It is not in the same species, these systems have to be trained on every individual brain, they are not reading some objective signal that is the same for everyone.

> For weeks, Ann worked with the team to train the system’s artificial intelligence algorithms to recognize her unique brain signals for speech. This involved repeating different phrases from a 1,024-word conversational vocabulary over and over again until the computer recognized the brain activity patterns associated with all the basic sounds of speech.

To use this type of system for lie detection, if such a thing is possible, you'd have to get each subject to give you thousands of example statements with truth/lie labels. This obviously defeats the purpose, and also doesn't really seem possible - does lying for a training exercise produce the same brain patterns as lying to actually cover something up? Probably not.

Your objections are that training is required and that where and how the lie is uttered might bear.

Mere technical hurdles IMO.

I would presume that someone being subject to a lie detector may have different incentives than those running the lie detector, and they may intentionally taint the data.

I think the point is, who would deliberately train a system to detect their own lies?

> who would deliberately train a system to detect their own lies?

Maybe an employee required to do so as part of on-boarding to a corporation or government org?

Or maybe someone in the process of a passport or visa application?

This podcast episode [0] with Sean Carroll and Nita Farahany scared the crap out of me on this topic, it seems inevitable.

This is the time to regulate neuro access prior to it becoming big business, and part of the TSA screening process.

[0] https://www.preposterousuniverse.com/podcast/2023/03/13/229-...

I was thinking it might be something everybody does in highschool or something. Every morning you spend an hour training your AI shadow. Everybody gets one. So useful, like a cell phone.

It still seems trivial to game. Make up some "tell" for your lies. Maybe every time you need to lie during the training period you squeeze your muscles, or think of hard math problems. It would be very hard for the AI not to fit to this fake "tell."

Those sound like techniques to fool a polygraph.

There are new infrared sensors in development that should see much more complex behavior in the brain, than say EEG. I’m sure even those could be gamed theoretically, but it will clearly become increasingly difficult as the technology improves.

If that's the sensitivity, what's the specificity? How well does it translate from the population it's trained on to other populations? In what contexts is the type of lying it detects useful to detect? I would assume using it on someone in a criminal investigation context without their permission would be a 5th and 6th amendment violation (as it would almost entirely subvert the usefulness of legal representation).

Unless someone figures out a way to do this without surgery from ten feet away the answer is that it won't.

Ya I was thinking the same thing. Requiring a brain operation to make it work would be a deal breaker. Need an MRI or something.

That seems like a pretty big leap. This doesn't require language understanding, just a translation between muscle movements and sounds. Lie detection is way more complicated.

It could detect intent to deceive. Or the brain-mode specific to lie-crafting.

There can never be a 100% accurate lie detector, only a 100% "thinks they're telling the truth detector". Ultimately human memory is deeply flawed and we're capable of having entirely false memories and swearing on our lives to things that never occurred. A machine which can perfectly read our brains can only get this messy imperfect mix.

Even in the sense of political intrigue, is it so hard to imagine someone so brainwashed they truly believe the lie they are telling you?

I would only call something a lie if it’s conscious and intentional, otherwise it’s a mistake

We don't have lie detectors even for AIs and we can look at every single bit inside them

To be fair, (most) humans have enough self awareness to (most of the time) know when they're lying. Theoretically, it's an easier problem.

Unintentional lie is an oxymoron, because that's just a mistake.

"Unintentional lie" overlaps with https://en.wikipedia.org/wiki/Self-deception.

no - this is not conceptually related to lie detection. Yes it uses ML to decode something, but that's where the similarity ends. This is decoding the patterns of brain activity used to generate speech.

Well yes. I'm thinking that if we can decode the brain in this one way then we can probably decode it in other ways too.

It would make trials much more straight forward events and allow us to deliver justice at scale, since we would now have a digital engine of truth.

And then we demand that all our police and lawmakers and public servants get hooked up to the machine and then the next day it's illegal tech.

since we would now have a digital engine of truth.

What are we living in, a dystopian sci-fi universe?

Reply on news.ycombinator.com