Jackson Pollock (1912 – 1956), the pioneer of Abstract Expressionism, challenged the artistic tradition of using an easel and brush by pouring and dripping paint onto canvases. His groundbreaking works had a childlike quality which belied their stunning complexity and sophistication. Driven by inner torment which compelled him to paint, Pollock attached large canvases to the floor, densely pouring, dripping and flinging paint embedded with sand or glass onto them with intense physical movement. Influenced by Picasso, Miró, and the Surrealists, Pollock also revolutionized a style of painting in which the work has no identifiable parts or point of emphasis, and is painted with a stream-of-consciousness technique called psychic automatism.