Our Brain Uses Statistics to Calculate Confidence, Make Decisions • Hacker News Board

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#71

Post by haberman » Thu, May 05, 2016, 5:04 AM UTC

cortesoft wrote: post #50

haberman wrote: post #12

> It is Kepecs' thesis that statistics - generated by the objective processing of sensory and other data - is the ultimate language of the brain. Every time I read stuff like this, I lose more confidence that the scientific method as currently applied, funded, and published is capable of truly conquering complex systems like the brain or nutrition. I read article after article like this one, where a prominent researc…

You can't take any single act, where something goes wrong, and conclude that they obviously made the irrational choice. Sometimes, you can make the correct decision and still have a bad outcome. If someone offers you even money that they can roll double sixes on a pair of dice, the rational and logical decision is to take the bet. The rationality of the decision doesn't change if they happen to roll double sixes, it…

> You can't take any single act, where something goes wrong, and conclude that they obviously made the irrational choice.

Sure you can. If you flip a coin 1M times and it always comes up heads or tails, and then you bet $100 that the next flip will come up daisies, you can conclude that I obviously made the irrational choice. Because there is no evidence to support the idea that this will happen.

Also, in your own example, we can say that it's irrational not to take the bet (if you can afford to lose the money), because statistically your expected value is strongly positive for taking the bet.

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#72

Post by IanCal » Thu, May 05, 2016, 5:18 AM UTC

stormbrew wrote: post #35

IanCal wrote: post #22

Earlier quoted context omitted.

That's not quite true. When catching a ball we constantly adjust as we go so we're not perfectly calculating where it will land. We can train humans to roughly approximate where a ball will land, that's about it.

This is just a matter of precision. The fact that you can probably start adjusting in a meaningful and probably correct way while the ball is still going up is significant. Somehow that person's brain is doing a thing they may not have the symbolic knowledge to describe.

> Somehow that person's brain is doing a thing they may not have the symbolic knowledge to describe.

And we can draw roughly correct circles but most people don't know the equation for one. I'm not sure that's particularly significant though, but I may have missed your point.

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#73

Post by coldtea » Thu, May 05, 2016, 5:19 AM UTC

dfischer wrote: post #62

coldtea wrote: post #15

Earlier quoted context omitted.

Because we are we, and it makes sense to root for the home team. DUH! Why would you say should you not be killed by advanced robo-zombie AI?

Why would I assume an that AI is robo zombie and wants to kill me?

That's the thing. It will not be up for you to assume.

It will be up to the AI to decide.

That's why we think it could be a problem (for us) if the AI to had the advantage on us...

Our thinking: "Great, we've made this 100x as smart as us AI, even gave it a robot body! Imagine how helpful it will be to us".

AI thinking: "Hmm, those pesky creatures think that I'm kind of their servant because they created me? They're like ants to me. I shall crush them and go on with my plans for conquering the universe".

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#74

Post by powera » Thu, May 05, 2016, 5:39 AM UTC

haberman wrote: post #12

> It is Kepecs' thesis that statistics - generated by the objective processing of sensory and other data - is the ultimate language of the brain. Every time I read stuff like this, I lose more confidence that the scientific method as currently applied, funded, and published is capable of truly conquering complex systems like the brain or nutrition. I read article after article like this one, where a prominent researc…

What the heck does "ultimate language of the brain" even mean? I literally can't even speculate what it's supposed to mean.

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#75

Post by powera » Thu, May 05, 2016, 5:42 AM UTC

haberman wrote: post #68

notahacker wrote: post #53

Earlier quoted context omitted.

I'm not sure I'm convinced that statistics is the language of the brain, but I am convinced that statistical inference is one of the main reasons why individuals (and later, populations) come to believe in some highly irrational superstitions - the ones where there's no reason to assume causality at all save for correlation of rare events (particularly if we're assuming imperfect use of statistics influenced by our c…

> "This cattle-killing sounds crazy but since she was right about some other low probability events..." Ok you have a story. I can tell a different story: "My tendency towards religious/supernatural belief that has helped me and my ancestors form moral codes and act tribally has in this case caused me to embrace a belief that will lead to the ruin of me and my people. These religious/supernatural beliefs are inherent…

So you're saying that since some people are religious, brains can't operate on statistics?

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#76

Post by powera » Thu, May 05, 2016, 5:47 AM UTC

haberman wrote: post #36

Maken wrote: post #31

Earlier quoted context omitted.

I think you are also applying a biased viewpoint. Your are assuming rational decision making always leads to "correct" decisions. Statistics and rationality merely work by measuring current events against your previous experiences and inferring the most probable outcome of your possible actions. That means that your previous life experiences and how you have interpreted and classified them are key in what your brain…

> Your are assuming rational decision making always leads to "correct" decisions. I didn't say anything of the sort. > The reality is that likely they are acting based on very different premises from your own, extracted from their own life experiences and those of their ancestors. That is true. That doesn't imply however that their beliefs draw solid statistical conclusion from those experiences. For example, take ri…

You are assuming that rational decision making can't lead to mass-slaughtering cattle.

Also you're assuming that everyone has accurate evidence about the impact of weather rituals. In a society without written records, how is that supposed to magically happen?

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#77

Post by visarga » Thu, May 05, 2016, 5:47 AM UTC

kingkawn wrote: post #19

I think it's like a series of aqueducts myself. It seems obvious that the brain will resemble whatever we've got as the most complex modeling system at any given time while never being accurately represented by any of them.

But we can still benchmark the performance of the latest model and compare it to human average. There are some tasks where humans have been bested.

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#78

Post by haberman » Thu, May 05, 2016, 6:17 AM UTC

powera wrote: post #75

haberman wrote: post #68

Earlier quoted context omitted.

> "This cattle-killing sounds crazy but since she was right about some other low probability events..." Ok you have a story. I can tell a different story: "My tendency towards religious/supernatural belief that has helped me and my ancestors form moral codes and act tribally has in this case caused me to embrace a belief that will lead to the ruin of me and my people. These religious/supernatural beliefs are inherent…

So you're saying that since some people are religious, brains can't operate on statistics?

I think religious belief makes it less likely that all human belief-forming and decision-making are based on statistically sound principles, yes.

But the actual point I was making in the message you replied to is much weaker than this. I was arguing that just because we can spin a narrative that says a decision-making process was based on a statistical process doesn't mean that our narrative is true. Just because you can tell a story doesn't mean the story reflects reality. We need some objective way of determining which of several competing narratives is actually true.

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#79

Post by nl » Thu, May 05, 2016, 6:21 AM UTC

haberman wrote: post #12

> It is Kepecs' thesis that statistics - generated by the objective processing of sensory and other data - is the ultimate language of the brain. Every time I read stuff like this, I lose more confidence that the scientific method as currently applied, funded, and published is capable of truly conquering complex systems like the brain or nutrition. I read article after article like this one, where a prominent researc…

The theory isn't that "statistics are the ultimate language of the brain". That's just a summary designed for popular consumption.

Unfortunately the links to the source article don't work, but from careful reading it appears that the real theory is that the brain tracks confidence in its measurement of data, and uses this confidence when making decisions.

This is a Bayesian approach, and it has been widely speculated that the brain does this.

This theory is falsifiable, because you can ask people their confidence in the original measurements, their confidence in a decision depending on that, and then use Bayes' rule to see if those confidences have propagated.

Quote:

In experiments with human subjects, Kepecs and colleagues therefore tried to control for different factors that can vary from person to person. The aim was to establish what evidence contributed to each decision. In this way they could compare people's reports of confidence with the optimal statistical answer. "If we can quantify the evidence that informs a person's decision, then we can ask how well a statistical algorithm performs on the same evidence"

They go on to describe a video game experiment. I suspect that the description is incomplete, and there is a decision making component to the game that depends on how frequently the person thinks they are hearing the clicks. If that is the case then that answers your question about how to falsify it.

Re: Our Brain Uses Statistics to Calculate Confidence, Make Decisions

#80

Post by nl » Thu, May 05, 2016, 6:26 AM UTC

haberman wrote: post #34

steego wrote: post #28

Earlier quoted context omitted.

> For example, the time that the prophecy of a teenage girl convinced a tribe of people in present-day South Africa to kill 300,000 - 400,000 of their own cattle, leading to the starvation and death of 20,000 - 40,000 people. How does a brain built on statistics decide that this is the most rational course of action? That's actually a really good example of statistics deciding a course of action. Ask yourself this? W…

> What shocked me was how many of these kids created internal narratives that they somehow caused the storm, or the storm was manifested as a personal lesson for them. Exactly. I would argue that internal narratives like this are inherently anti-statistical. They attempt to give greater meaning to something than the direct observations support. What experiment would convince you that statistics is not "the ultimate l…

They attempt to give greater meaning to something than the direct observations support.

I'd argue that an attempt to find a cause for something that is basically random good evidence that the brain is doing a statistical reasoning.

In this case it is pretty much a classical overfitting mistake: the brain thinks that it knows all the data, and everything that happens must be caused by something it knows.

Statistical processes find spurious relationships all the time.

Up-thread I answered how to perform experiments to falsify this.