Karl Lashley found in the 1930's that he could not localize memory in any one area in the brain. Decades later the surprising and well-known case of H.M. would show that brain damage localized to the hippocampus results in severe memory impairment. H.M. retained long term memory, but lost the ability to create new conscious memories. Unconscious memories, such as physical skills, proved to be another matter. H.M. improved at mirror-writing tests, though he retained no conscious memory of having practiced or ever tried mirror-writing before. If the hippocampus was essential to laying down, coding, and condensing long-term memory, other types of memory had an apparently independent means of functioning. Neuroimaging research has shown that working memory consists of separate phonological and visuo-spatial loops that a third, central-executive part, uses to coordinate with memory and attention. (Carter, pp. 188-191). See also Scott Carpenter's paper on working memory.