"Still, a man sees what he wants to see, and disregards the rest." You just know that those words from The Boxer, penned by Paul Simon in 1968, are true.
Maybe because seeing what you don't want - or, at least, don't expect - to see is a lot rougher on the melon. This "strain your brain" hypothesis finds support in work published a few weeks ago in the Journal of Neuroscience by Max Planck Institute for Brain Research researchers. Monitoring brain activity with functional magnetic resonance imaging, they found that people's visual centers wheeled into much higher levels of activity when patterns of motion they were watching shifted from predictable to unpredictable. The implication is that the brain constructs a model of what it expects to happen, and is confounded and forced to work harder when the unexpected occurs instead.
This also calls to mind a comment by Gary Glazer, MD, the award-winning head of Stanford's radiology department, that I didn't have enough space to include in my profile of him six or seven months ago. I asked Glazer what's the secret that makes some radiologists especially expert in teasing out a diagnostic finding from the rather ambiguous Rorschach-card-like radiograms they read. He responded:
We see what we look for, and we look for what we know. If you don't know very much, you're not going to do very well - it’s a disaster.
Worse than not knowing much, as every good scientist is keenly aware, is being too sure your model is accurate. Or, in a more homely formulation attributed variously to Mark Twain, Lao Tsu, and Anonymous: "It isn't what you don't know that gets you into trouble. It's what you know for sure that just ain't so." It's tough enough to see the actual truth when it pops up before your eyes, without making it an even more uphill process by mistaking certainty for certitude.