I think we’re undergoing somewhat of a slow revolution in the cognitive sciences. The field is slowly coming to focus on the central role of prior expectation in cognition.
Evidence that prior expectation has a large effect on the interpretation of sensory input is by no means new, but it seems to me that people are focusing on prior expectation more and more when they theorize about the mind. For example:
* The recent post about hypnosis and the Stroop effect (the nytimes article focuses on this aspect of the work)
* The fact that most of the connections between lower-order sensory areas and higher-order areas are feedback connections from the higher to the lower
* The fact that imagining a visual image causes activation in (see , there’s a bunch of followup studies to that one too)
* This may be just a rumor, but I’ve heard that it’s been demonstrated that when you saccade, that near the end of the interim period when you cannot see, your primary visual cortical cells start firing in the patterns corresponding to what you expect to see at the new location. Does anyone have a source for that (I’ll ask the person who told me if they have a citation)?
* Jeff Hawkins’s effort to make theories of the mind centered on prediction
* The current fad in Bayesian analysis in theoretical cognitive science (which provides a mathematical framework for computing probabilities which take into account both prior expectation and evidence)
I don’t mean to imply that this potential paradigm shift is something that people are unaware of; indeed, Kosslyn, Hawkins and others have long been avid proponents of the view that sensory processing (as well as other aspects of cognition) is best understood as centered around prediction and prior expectation, not incoming sensory data.
 Kosslyn, S. M., Alpert, N. M., Thompson, W. L., Maljkovic, V., Weise, S. B., Chabris, C. F., Hamilton, S. E., Rauch, S. L., & Buonanno, F. S. (1993). Visual mental imagery activates topographically organized visual cortex: PET investigations. Journal of Cognitive Neuroscience, 5(3), 263–287.