Remembered duration: Evidence for a contextual-change hypothesis.

Two experiments used levels-of-processing tasks to investigate hypotheses on remembered duration of relatively long intervals. In Experiment 1, level of processing (shallow or deep) of presented information did not affect remembered duration, even though it had a substantial effect on memory for individual stimulus events. In Experiment 2, an interval containing different kinds of tasks (both shallow and deep processing) was remembered as being longer than one containing a single kind of task (either shallow or deep processing). Current formulations of event-memory, attentional, and informational hypotheses on remembered duration cannot easily explain these findings. However, the findings are consistent with a contextual-change hypothesis, which emphasizes memory for the overall amount of change in cognitive context during an interval. Implications regarding contextual factors in memory are discussed.