“Your face, my thane, is as a book where men may read strange matters.” (Shakespeare, Macbeth)

A current theory describes the human brain as a “prediction machine”: It posits that our brain is constantly constructing hypotheses of what will happen next. When there is sensory input, it is quickly matched or corrected/updated by comparing it with already existing hypotheses. This process increases the efficiency of our brain – that is, our data processing and reaction abilities.

According to this theory, perception can be understood as a creative process: Besides the sensory impressions, our expectations and experiences as well as our existing knowledge play a key role for the occurrence and processing of our perceptions. But this can also lead to deceptions and distorted perceptions.