Complex sentence: Selective retention is the process when people remember messages that are closer to their interests, values and beliefs more accurately, than those that are in contrast with their values and beliefs, selecting what to keep in the memory, narrowing the informational flow.
Split into simpler sentences: Selective retention is the process when people remember messages that are closer to their interests, values and beliefs more accurately, than those that are in contrast with their values and beliefs. Selecting what to keep in the memory, narrowing the informational flow.