I found a great study that’s summarized in The Robot’s Rebellion. It freaked me out (the writing can be dense but it’s worth it):
Some patients who have sustained damage in their visual cortex display a seemingly puzzling set of symptoms. They develop a blind spot in their field of vision: they report seeing nothing in a particular portion of their visual field.
However, when persuaded to make a forced choice about a fixed set of stimuli (for example, to choose one of two shapes or lights) presented into their blind field, they perform with greater than chance accuracy despite their phenomenal experience of seeing nothing.
For example, when choosing between two stimuli, their choices are 70 percent correct despite the fact that on each trial they insist that they see nothing.
Often such patients have to be persuaded to continue to keep making the forced choices which they view as pointless. Many report that they are simply guessing, that they “couldn’t see a darn thing,” and question what the experimenter could possibly find out from such a pointless exercise.
Basically, someone has a blind spot. The tester puts a shaped object in the blind spot and asks the subject to guess the shape. The tester gets bored/frustrated because they can’t see the shape at all, yet they guess the correct shape more than 70% of the time.
This is crazy! The brain is updating with information and the subject is unaware of the entire process.
Some version of this has to be happening constantly.
And some people think brand advertising doesn’t affect them?!
We have such a small idea of what’s going on behind the scenes: how we make decisions, why we want something, what scares us, etc.
Maybe there’s something to the idea of being careful about what you put into your mind.