Filling in the blanks part 2Posted: December 1, 2005 at 12:04 am in cognition
I was thinking more about the topic of how our mind fills in the blanks last week during the Messiah concerts, particularly in the “He was despised” aria. I meant to write this up on Sunday or Monday evening, but didn’t get around to it. So, of course, I’m writing it up after a two and a half hour chorus rehearsal. Because if I don’t, I’m not sure when I’ll have time to blog again (another rehearsal tomorrow (Thursday) night, plans on Friday night, the BrainJam on Saturday, brunch Sunday morning, ultimate frisbee Sunday afternoon, and then rehearsal Monday-Wednesday evenings (with a special bonus Wednesday afternoon rehearsal), and concerts Thursday through Saturday next week. When did my life get so crazy?)
One of the things I was grasping for at the end of the last post was “something about the connection between how our brains fill in the blanks, and how that reinforces our worldviews”. And I think I have some ideas about that now, with applications and a tie-in to another post I had half-written but gotten stuck on. So this thread will probably be a set of at least three posts, if not more.
One of the things that struck me about how our brains fill in blanks is that I already had a theory for this in one of my cognitive subroutines posts from last year.
When our brain is presented with a situation with certain stimuli, it grabs among its set of cognitive subroutines, finds the one with the closest matching set of inputs, and uses it, even if itâ€™s not a perfect fit.
Or, to use Jeff Hawkins’s terminology, a set of cortical cells are activated by a stimulus, and based on the cells’ responses to other similar stimuli, those weak connections to other stimuli are activated since there are no strong activations from the original stimulus.
Using either formulation, the idea is that when your brain is presented with an incomplete pattern, it grabs among the patterns that it does have to fill out what it doesn’t know. It fills in the blanks. This ties into my statement from the last post where I noted “that when we donâ€™t know something, we tend to assume whatever works to best preserve our worldview.” It’s even worse than that – we don’t assume it consciously. It happens completely automatically.
My point is that my brain is a fantastic pattern recognition machine. It can make a pretty good guess as to what goes in the blanks most of the time based on its previous experience. It is completely necessary for us to perceive the world as a continuous place – we assume that even though we only see the back end of a car poking out of a driveway, there is a front end associated with it. Our senses do this automatic filling in of blanks all the time. One of the insights of On Intelligence is that our cortical cells treat all inputs in the same way, looking for patterns of stimuli that occur together and using those patterns to make predictions about the world around us, whether the patterns are from our senses, or from processing what we think other people are going to do. Patterns are patterns, and our brain’s going to do the best it can to make our perception of the world continuous by filling in blanks wherever it can (as an aside, we have to beware of stereotypes and other breakdowns in the system, where the blanks are being filled in based on faulty assumptions (inexperience, etc.)).
I think I’m going to end this post here. Tonight I took a stab at hand-waving-ly justifying how and why our brains fill in blanks when presented with incomplete patterns, with the relevant point being that it fills in those blanks from its own experience. My next post will be examining the implications of how our brains fill in blanks in an actual real-world scenario (*gasp*). And then there’s a post tying this all into my adapting the global to the local thread. Somehow. It’s all tenuously connected in my head, but I may have to play with it some more to make it work.
“He was despised” is an aria in Part Two of the Messiah for the alto soloist. It’s slow, lugubrious and, frankly, boring, so it seems like it goes on _forever_. And then it repeats, because Handel decided once wasn’t enough. It’s painfully long. I’ve been in several Messiahs at this point, and it just doesn’t matter how good the alto soloist is (countertenor soloist in this case), the aria is just boring. During most of the other arias, the chorus is paying attention to the soloist, admiring their vocal acrobatics; during “He was despised”, I think we’re all struggling to stay awake, staring off into the audience, etc. Or thinking about the cognitive origin of filling in the blanks, like me.
“completely automatically”: I want to mention Brad’s post about choice blindness (pointing at this study) here, even though it’s not entirely relevant to my main point, mostly to illustrate how your brain does all sorts of weird stuff long before stimuli reach your conscious brain.