Is there a memory profit after repeated learning of subject-performed actions? Comparing direct and long-term memory performance level as a function of age.

The present two studies investigated the possibility for improvement and maintenance of episodic memory in young and older adults. In a first study, the performance-enhancing effect of two separate as well as combined learning devices, enactive encoding and repeated learning, was tested. With a time lag of one week, four different series of 30 action phrases were encoded either verbally or by enacting them symbolically. Memory was assessed in four immediate free recall tests. In a second study, the maintenance of the memory profit was tested in an unexpected fifth session half a year later. As expected, there was a steady improvement of memory performance as a function of repeated learning in study one. This holds true regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Moreover, younger adults outperformed the elderly regardless of type of encoding. The combination of the two learning devices was not efficient enough to eliminate aging effects in episodic memory. However, memory flexibility is demonstrated also in the elderly. In the long-term follow-up, maintenance of learning and memory could be found in all participant groups.