Modernism emerged in the late 19th century as artists sought new styles and materials to break from historical conventions. Neo-expressionism arose in the 1970s in response to minimalism and conceptual art, bringing back traditional painting techniques. Abstract expressionism used brushstrokes and texture to convey emotion through the act of painting itself and was exemplified by artists like Pollock, Rothko, and de Kooning. Optical art exploited optical illusions through techniques like perspective illusion and chromatic tension to create the impression of movement, as seen in the works of Vasarely.