The Effect of Repeated Performance and Delay Time on Story Recall in Normal Pressure Hydrocephalus and Healthy Elderly Groups

Objectives: This study aims to analyze differences in information retrieval abilities between a normal pressure hydrocephalus (NPH) patient group and a healthy elderly (HE) group using a story recall task, and to examine the effects of performance timing (first, second) and delay intervals (5 minutes, 20 minutes) on recall performance. Methods: Thirty HE subjects and thirty-one NPH patients were randomly assigned to either a 5-minute or 20-minute interval condition and performed the story recall task. Differences between groups in event sequencing scores, information unit (IU) scores, and frequency of information-finding behaviors (revision, repetition, filler) were analyzed across performance timing and delay intervals. Results: First, the HE group had significantly higher event sequencing scores than the NPH group. Scores improved in the HE group during the second performance, while no change was observed in the NPH group. Second, the HE group had significantly higher IU scores than the NPH group. IU scores improved in the HE group during the second performance, while no change was observed in the NPH group. Third, for the filler of information-finding behaviors, no difference was observed between groups during the first performance, but during the second performance, the frequency in the HE group was significantly higher than that in the NPH group. Conclusion: These findings suggest that comparing performance on a story recall task across repeated trials is a useful assessment tool capable of sensitively distinguishing differences in cognitive and linguistic performance between NPH and HE groups.