Is "memory-for-when" universal? Group and individual variability in temporal position memory for words, faces, and classrooms.

Many contemporary theories of memory assume that everyone automatically stores temporal contextual information about all types of encountered information, yet most studies on this topic have used words and ignored individual differences. Five experiments accumulated evidence that explicit storage of temporal context information does not appear to occur automatically for all people and types of memoranda. We collected judgments of temporal position (memory-for-when) for words (Experiments 1 & 3), faces (Experiments 2A, 3, 4, and 5), and classrooms (Experiments 2B & 3). At the group level, for each of these memoranda memory-for-when was sensitive to the original input position and showed a temporal primacy effect reflecting better memory for position for items near the beginning of the list, indicating some automatic storage of temporal context information. However, memory-for-when was significantly better for words than classrooms, with faces in the middle. Moreover, individuals varied dramatically in their ability to indicate memory-for-when, especially for classrooms where many people performed at or near chance. Taken together, the data suggest that explicit memory-for-when may be dissociable from the more implicit use of temporal contextual information that is theorised to occur during free recall.