The document describes three mental modes - production/expert mode, learning mode, and mixed mode - and how they affect human interactions. Production/expert mode relies heavily on prior knowledge and rejects information that does not align. Learning mode can start with little prior knowledge, caches new information, and can recycle or reject information after study. Mixed mode uses two levels of processing, preliminary scanning followed by caching, and only rejects clearly spurious information after consideration. The effectiveness of interactions depends on the mental modes of participants and their ability to switch modes as topics change.