Effect of prosocial motivation on prospective memory and its different components in older adults under different attention loads

Prospective memory is the ability to remember to perform a planned activity in a future situation. Because of the strong sociability of older adults, their prospective memory performance is easily affected by prosocial motivation. The purpose of this study was to explore the influence of prosocial motivation on prospective memory and its components in older adults. Specifically, we recruited 101 older adults (aged 60-75 years) and 115 younger adults (aged 18-25 years) to participate in this experiment. We used a 2 (group) × 2 (age) × 2 (attention load) between-subjects design. Prosocial motivation was induced by instruction. The results showed that, compared with the control group, the accuracy of prospective memory and ongoing task in the prosocial motivation group was higher under different attention load and age conditions. Concurrently, the response speeds of the prospective memory and the ongoing tasks were slower. The results from the beta-MPT model analysis showed that under the condition of low attention load, the prospective component of the prosocial motivation group was higher than that of the control group. The results showed that prosocial motivation could promote prospective memory performance of both older adults and younger adults, an outcome unaffected by attention load. Prosocial motivation mainly ensures the monitoring and confirmation of prospective memory cues in high attention load condition by slowing down the response speed of both younger and older adults, thus improving prospective memory performance. The registration number is ChiCTR2500105119.