On Nature online a news article reports about research by Cerf, M. et al. Nature 467, 1104-1108 (2010) which shows how humans can use thinking to alter perception of competing visual images
In the news Dr. Moran Cerf gives an interesting interpretation of his EXPERIMENTS:
"The environment offers some reality," he says, "but your own brain can shape it and override it with its internal deliberations."
The THEORY for this has been developed in the last 40 years within the theory of knowing called Radical Constructivism http://www.univie.ac.at/constructivism/
Antonio Damasio & Kaspar Meyer write in Nature 454, 167-168 (10 July 2008) "Convergence–Divergence Zones" (CDZs) – (‘mirror neurons’) that mirror neurons act not so much as "mirrors" but "more like puppet masters, pulling the strings of various memories."