Schizophrenia and Working Memory
That problems with working memory may have a role in schizophrenia has been touched on before in this blog and now a new study indicates what that role might be. Previously scientists thought that the one problem with the disorder could be with automation processing of ordinary tasks i.e. learning by repetition to do things on auto pilot. Dutch researcher Tamar Van Raalten studied the role of working memory in automation and established that it is not the automation process but the processing of new information that was the cause of problems.
Van Raalten, using an fMRI scanner, asked subjects to perform tasks in which they had to remember a series of letters, something that would be accompished in working memory, and discovered that the more the tasks were repeated, the lower the brain activity became in the areas of the brain associated with working memory. But this activity was not compensated for by other areas of the brain involved in long term memory. By automating the letter series the subjects were releasing working memory capacity allowing it to process new information. Van Raaltlen concluded that this restructuring of incoming information was another function of working memory, a process known as chunking. For example to remember 1232673445 you would clump numbers together as you might a phone number, 113 276 3445 . This allowed working memory to be freed up to process new information. Her initial conclusion, in observing schizophrenic patients performing the same tasks, was that their working memory was less efficient and automation did not proceed as well as with healthy subjects. Van Raalten went on to observe that schizophrenic patients process less information than healthy subjects. However, the testing revealed automation proceeded as well as with healthy subjects but subsequently, working memory was not released to deal with new tasks. Further testing revealed that the working memory in schizophrenic subjects struggled with the processing of information that continually changed, leading to the conclusion that Schizophrenics may have more of a tendency to adopt automatic strategies in circumstances that demand flexible behavior.