http://en.wikipedia.org/wiki/P3b

I found this article while researching something else and I was intrigued. Is this a neural correlate of confusion?

The P3b has been a prominent tool used to study cognitive processes for several decades. More specifically, this ERP component has played a key role in cognitive psychology research on information processing. Generally speaking, improbable events will elicit a P3b, and the less probable the event, the larger the P3b.^[3] However, in order to elicit a P3b, the improbable event must be related to the task at hand in some way (for example, the improbable event could be an infrequent target letter in a stream of letters, to which a subject might respond with a button press). The P3b can also be used to measure how demanding a task is on cognitive workload.^[4]

If so, awesome. Hats which actually do sound an alarm when your models are proven wrong could be arranged. I suspect that there might be things that make it not useful for that (like, if it also correlates with a bunch of other things). Seems like it's at least worth mentioning.