Learning and Memory: The Remember-Know Task

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Our experience of memory is varied and complex. Sometimes we remember events in vivid detail, while other times we may only have a vague sense of familiarity. Memory researchers have made a distinction between memories that are recollected versus those that are familiar. A recollected item is one that is not only remembered, but carries with it details of the time at which it was learned or encoded. Like a recollected item, a familiar item is also remembered, but is void of any details about the circumstances surrounding its encoding. Many studies of recollection and familiarity have focused on the medial temporal lobe (MTL), specifically the hippocampus, since its involvement in memory encoding, consolidation, and retrieval is well-known and well-studied.^1-3

This video shows how to administer the Remember-Know task⁴ to compare brain activation in these two types of memory retrieval. In this context, remember is another term for recollection, while know refers to memories that are familiar but not explicitly recollected. In this version of the Remember-Know task, participants are exposed to a series of color images, and asked to remember what they see. Inside an fMRI scanner, they will be exposed to both images that were studied and to novel images, and they will make a "remember," "know," or "new" judgment about each image, indicating what kind of memory they have for that item. Following the scan, whole brain and hippocampal activity will be examined to determine differential activity related to recollection and familiarity. This study is based on a study performed by Gimbel and Brewer.⁵