From the 1890s until his death in 1939, the Austrian physician Sigmund Freud developed a method of psychotherapy known as psychoanalysis. Freud's understanding of the mind was largely based on interpretive methods, introspection and clinical observations, and was focused in particular on resolving unconscious conflict, mental distress and psychopathology. Freud's theories became very well-known, largely because they tackled subjects such as sexuality, repression, and the unconscious mind as general aspects of psychological development. These were largely considered taboo subjects at the time, and Freud provided a catalyst for them to be openly discussed in polite society. While Freud is perhaps best known for his tripartite model of the mind, consisting of the id, ego, and superego, and his theories about the Oedipus complex, his most lasting legacy may be not the content of his theories but his clinical innovations, such as the method of free association and a clinical interest in dreams.
Freud had a significant influence on Swiss psychiatrist Carl Jung, whose analytical psychology became an alternative form of depth psychology. Other well-known psychoanalytic thinkers of the mid-twentieth century included Sigmund Freud's daughter, psychoanalyst Anna Freud; German-American psychologist Erik Erickson, Austrian-British psychoanalyst Melanie Klein, English psychoanalyst and physician D. W. Winnicott, German psychologist Karen Horney, German-born psychologist and philosopher Erich Fromm, and English psychiatrist John Bowlby. Contemporary psychoanalysis comprises diverse schools of thought, including ego psychology, object relations, interpersonal, Lacanian, and relational psychoanalysis. Modification of Jung's theories has led to the archetypal and process-oriented schools of psychological thought.
Austrian-British philosopher Karl Popper argued that Freud's psychoanalytic theories were presented in untestable form. Psychology departments in American
Links: between psychological activity and brain and nervous system function also became understood, partly due to the experimental work of people such as English neuroscientist Charles Sherrington and Canadian psychologist Donald Hebb, and partly due to studies of people with brain injury. These mind-body links are explored at length by cognitive neuropsychologists. With the development of technologies for measuring brain function, neuropsychology and cognitive neuroscience have become increasingly active areas of contemporary psychology. Cognitive psychology has been subsumed along with other disciplines, such as philosophy of mind, computer science, and neuroscience, under the umbrella discipline of cognitive science