At the Univ. of Minnesota during WW II found that hungry people spend much of their time thinking or phantasizing about food, and took up hobbies and occupations that are associated with food. The evidence is weak for such a process. However, it has been found that the expectations of people affect how they interpret ambiguous social situations. Distinguish between signs, signals, and symbols. Memories tend to be reconstructive, combining elements from storage and the current circumstances of the individual.
Strong emotions produce tunnel vision and hence restrict the ability to process information.
This is one reason eye witness testimony is so untrustworthy.