Discussion
cognitive auditory discrimination
To the best of our knowledge, this study is the first to estimate the responsiveness and MCID of dual task performance involving cognition and hand function for older adults with and without CI after SCET. Among the sample of CH adults, there were small yet consistent intervention effects to the cognitive components of different dual task paradigms; the effect on the exercise task was stronger when paired with the cognitive mental arithmetic task than when paired with cognitive auditory discrimination task.This study suggests that the dual tasks combining cognition and hand function in the CH group show fair responsiveness to the SCET intervention. In the CH group, the dual task measures showed small responsiveness, except BBT performance when tasked with FD; in the CI group, only FD performance when tasked with BBT showed small-to-medium responsiveness. Both dual tasks may represent different levels of difficulty in successful execution. The dual task of SST and BBT required higher cognitive demand that SST involves working memory [For the CH group, there may be a ceiling effect [For participants in the CI group, the dual task of SST and BBT may be too challenging to be responsive to change and a floor effect [The estimates of distribution-based MCID are greater than those of anchor-based MCID of all dual task measures in both groups (distribution-based MCIDs: CH group: 1.20–5.99; CI group: 1.24–7.69; anchor-based MCIDs: CH group: 0.32–3.77; CI group: 0.67–1.47). The observed discrepancy between the two methods may be due to the different ways in which changes are detected. The distribution-based approach measures changes by calculating the statistical properties of the observed sample, including participants who improved or declined after the intervention. The anchor-based approach uses an external criterion is used as a reference for measuring changes [Our findings indicate that SST performance when tasked with BBT may serve as a MCID index for the CH group following SCET, while FD performance when tasked with BBT may serve as a MCID index for the CI group following SCET. Participants in the CH group achieved meaningful change along with a greater MCID estimate of SST performance when tasked with BBT (MCIDs = 2.09–2.36) than those in the CI group (MCIDs = 0.67–1.24). As noted earlier, the dual task of SST and BBT requires higher cognitive demand and is more complex than the dual task of FD and BBT. Accordingly, the findings suggest that participants in the CH group had better cognitive abilities and potential for improvement in the progress of cognitive performance and may have greater potential improvement from the SCET compared to those in the CI group. In terms of FD performance when tasked with BBT, participants in the CI group achieved meaningful change along with a greater MCID estimate (MCIDs = 1.47–2.18) than those in the CH group (MCIDs = 1.00-1.20). It is possible that the CI group had worse baseline FD performance when tasked with BBT (mean = 13.60) and more room to be improved than those in the CH group (mean = 15.79) when performing the easier dual task requiring the fundamental cognitive ability of sustained attention.Given the small responsiveness of BBT performance when tasked with SST and with FD and the huge ranges between distribution- and anchor-based MCID estimates for both groups, BBT performance when tasked with SST and with FD were not suggested to be used as a MCID index after SCET for either group. Also, considering that the SCET intervention did not demonstrate significant improvements in BBT performance among older adults with CI, it may be worthwhile to explore alternative physical tasks such as marching on the spot or performing upper/lower limb workouts with resistance in future dual task paradigms for this specific population.The results of the 12-week SCET intervention in a group-based setting, combining various cognitive tasks with multiple exercises for a total dose of 1080–1440 min, indicate improvements in attention (FD) and working memory (SST) performance during dual task conditions, as well as EFs (dual task performance) in CH older adults. These findings are aligned with previous SCET studies that employed multicomponent cognitive training (involving attention, memory, arithmetic, and language) combined with physical exercises (aerobic and resistance exercises) and reported improved attention and working memory performance in CH older adults [In the CI group, attention showed improvement, which is consistent with previous research using multicomponent SCET [