Telling the same story twice: Output monitoring and age

When people have to remember to perform an act in the future, they must also keep a record of the act already performed so as not to repeat it. This neglected aspect of everyday memory was investigated by examining the alleged preponderance of action repetitions in old age (e.g., telling the same story over and over, taking a medicine too often, etc.). We propose that such action repetitions stem from a deficiency in the monitoring of actions performed. Although older subjects remembered fewer words from a study list than younger subjects, they were more likely to repeat them in free recall (Experiments 1 and 2). When later presented with the study words and asked to judge whether they had recalled them in a previous recall phase, older people classified more recalled words as unrecalled. In Experiment 3 subjects classified words according to (a) whether they had appeared in a study list (input monitoring) and (b) whether they had been previously classified by them on the test list (output monitoring). The older subjects were more deficient in output monitoring than in input monitoring. Their most frequent error was classifying old-output items as new-output items, the error assumed to underlie action repetition. Several interpretations of these results were proposed.