Peter Attia· MD
what happens on the ratio schedule is that the rat has this very even pressing that goes on this very even somewhat quick but not mad press press press press food press press press press and then if it's every five minutes the rat twiddles its thumbs until it's almost five minutes and then it goes crazy so you get this burst of activity it's almost like they don't want to miss a second they want to make sure that they get that food exactly they don't want to give up one second where they could have had food and so you get this big burst of activity then you can also take a ratio or interval schedule instead of it being fixed you can make it variable and what that means is it's now on average is the way that you can think about that so let's say on average every 20 lever presses you'll get food or on average every 5 minutes you'll get food so now instead of this big burst of activity on the interval schedule on average every 5 minutes because they're not sort of waiting and then oh I think it's about 5 minutes and they go now they're pressing pretty steadily the whole time because they're not sure anymore right is it going to be the second or not and then on the variable ratio schedule you get the same thing you get a lot of pressing very quickly because they don't know is that the next press or not so that's all kind of interesting and you'll see you different activity pending on whether its variable or not what's interesting is when you try to extinguish the behavior this is what's really key so when you extinguish a behavior what you do is you just withdraw the reward so now you've trained the rat it's pressing the lever and then you just stop giving the rat food and the question what does it do when it's fixed it stops doing the thing super fast it's like hey wait a minute like I've been pressing a hundred presses of this stupid lever you haven't given me any food I give up I have figured this out there's no food coming my way same thing if you're doing it by time but when you make it variable they just don't stop and it's particularly bad when it's a variable ratio schedule so I think about it like this so anybody who's ever watched people sitting at a bank of slot machines in Las Vegas those are on a variable ratio schedule that you'll get a reward it's gonna be on average a certain number of plays you could get a reward five plays in a row you could go 80 plays without really getting much in return and you kind of don't know cuz it's on average and what happens to people sitting at those slot machines is that they'll be going along and there'll be no reward and you'll hear them say a thing I'm do I'm do and what that means is that it doesn't matter what you do to that machine you could just turn it off what they think is no it must be the next press it must be the next press and this is exactly what happens to the rats in the Skinner box you train them that on average every 20 presses they get food and that means sometimes they're getting three pellets in a row and sometimes they're going 80 presses without getting food that's obviously out at the tail no pun intended but it's just an average and now you would draw it and they just never stop pressing the lever and it looks just like what humans do and I sort of always imagine the little rats and the cages saying I'm do so this is exactly the