A filmmaker whose career began in the silent era and stayed strong through the advent of sound, color, and television, Alfred Hitchcock was one of the leading directors of his day. Both critically lauded and commercially successful, he had an enormous influence on the development of the thriller and the black comedy. His stylistic influence has been felt in his popularization of the expressionistic techniques he learned in Germany during the silent era, his use of special effects and dream sequences, and his use of the famous "MacGuffin" plot device. His effect on culture has been felt even outside the realm of film and television: his fascination with the criminal mind helped to introduce the general public to many of the foundational ideas in modern psychology, by portraying mentally ill criminals realistically instead of as the sheerly unpredictable madmen who had populated most films and entertainment.