Test-retest consistency of Virtual Week: A task to investigate prospective memory

The present study reports test-retest consistency of Virtual Week, a well-known measure of prospective memory (PM) performance. PM is the memory associated with carrying out actions at a specific moment in the future. Patients with neurological disorders as well as healthy older adults often report PM dysfunctions that affect their everyday living. In Experiment 1, 19 younger and 20 older adults undertook the standard version of Virtual Week (version A). Older adults showed lower performance compared to younger participants. However, the discrepancy between groups was eliminated at retest. Experiment 2 was conducted to investigate if remembering of PM content determined the improvement observed in older adults at retest in Experiment 1. To this end we created a parallel version (version B) in which we varied the content of the PM actions. Fifty older adults were assigned to one of the two experimental conditions: Version A at test and version B at retest or vice versa (25 participants in each condition). Results showed no group differences in PM performance between version A and version B; moreover, no effect of test-retest was found. The study confirmed that Virtual Week is a reliable measure of PM performance and also provided a new parallel version that can be useful in clinical setting.