Saturday, June 26, 2010

Password

A few days ago, a friend of mine had her GMail account compromised, resulting in much stress for all concerned. This prompted me to change my passwords.

That was three days ago. Since then, I've logged into GMail maybe ten or fifteen times, and every single time I've initially typed the old password. Sometimes, I catch myself and change it before hitting "enter", but usually not. Access denied. Oops. It's getting slightly better, but I think it'll be a good few days before I'm entering the new password as automatically as I did the old one.

It's not hard to see why this kind of thing happens: I'd typed in the old password hundreds, probably thousands, of times over the course of at least a year. It had become completely automatic. That kind of habit takes a long time to learn, so it's no surprise that it takes quite a while to unlearn (though hopefully not quite as long).

Psychologists will recognize the distinction between declarative memory, my concious knowledge of what my new password is, and procedural memory, my ability to unconsciously type it. It's also commonly known as "muscle memory": this is misleading because it's stored in the brain, like all knowledge, but it nicely expresses the feeling that it's your body that has the memory, rather than "you".

Damage to the hippocampus can leave people unable to remember what happened ten minutes ago, but perfectly capable of learning new skills: they just don't remember how they learned them. But you don't have to suffer brain damage to experience procedural knowledge in the absence of declarative recall. I've sometimes found myself unable to remember my password and only reminded myself by going to the login page and successfully typing it. I knew it all along - but only procedurally.

The thing about procedural knowledge is that when it works, you don't notice it's there. So we almost certainly underestimate its contribution to our lives. If you asked me what happens when I log in to GMail, I'd probably say "I type in my username and my password". But maybe it would be more accurate to say: "I go to the login screen, and my brain types my username and password."

Can I take the credit, given that sometimes I - my conciousness - don't even know the password until my brain's helpfully typed it for me? And while in this case I do know it some of the time, much of our procedural knowledge has no declarative equivalent. I can ride a bike, but if you asked me to tell you how I do it, to spell out the complex velocity-weight-momentum calculations that lie behind the adjustments that my muscles constantly make to keep me upright, I'd be stumped.

"I just sit down and pedal." But if I literally did that and nothing more, I'd fall flat on my face. There's a lot more to cycling than that, but I have no idea what it is. So can I ride a bike, or do I just happen to inhabit a brain that can? Isn't saying that I can ride a bike like saying that I can drive just because I have a chauffeur?


Take this train of thought far enough and you reach some disturbing conclusions. Maybe it's not so hard to accept that various skills lie outside the reach of our concious self, but surely the decisions to use those skills are ours alone. Sure, my brain types my username and password for me, but I'm the one who decided to login to GMail - I could have decided to turn the computer off and go for a walk instead. I have Free Will! Like George W. Bush, I'm the Decider. My brain just handles the boring details.

But isn't deciding a skill too? And willing, remembering, thinking, judging, feeling, concluding - I can do all those things, but if I knew how I do them, I'd win the the Nobel Prize in Physiology or Medicine because I'd just have solved the hardest questions of neuroscience. So can I take credit for doing them, or is it my brain?

Ultimately, every concious act must be constructed from unconscious processes; otherwise there would be an infinite regress of conciousness. If the world rested on the back of a giant turtle, what would the turtle stand on? Turtles all the way down?

Link: The Concept of Mind (1949) is a book by the British philosopher Gilbert Ryle, from which I "borrowed" the ideas in this post, and which was probably the one book that most inspired me to study neuroscience.

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