APA Dictionary of Psychology

in psychodynamics, the psychological functions, collectively, that help individuals meet environmental demands, protect the ego, satisfy inner needs, and alleviate internal and external conflicts and tensions. Among them are (a) language, which enables expression of thoughts; (b) memory, which stores information needed in solving problems; and (c) perception, which involves recognition and interpretation of phenomena. In addition, in psychoanalytic and psychodynamic theory, various defense mechanisms, such as rationalization and compensation, help to prevent anxiety and protect self-esteem.