The Effects of Dual-Task Training on Global Cognitive Function, Executive Function, Working Memory, Sleep, Behavioral Disturbances, Balance, and Flexibility for People With Mild Cognitive Impairment and Mild Dementia

Sample size calculation: Investigators use the G*Power sample size calculator under an F test with an analysis of variance based on some criteria, for instance: effect size 0.2 (small), power 80%, four times measurement, four groups (cognitive training, motor training, dual-task training, and control group) and α error probability of 0.05. The sample size from the calculator yields 48 in total, considering 50% attrition rate, finally 72 participants (18 participants for each group) will be recruited.

Sample recruitment: Investigator will use a CONSORT flow diagram to describe the phases of this study. A purposive sampling technique will be used in this study to specifically select the nursing home. Following this, eligibility interviews and screening test using MMSE (The Mini Mental State Examination) and The Clinical Dementia Rating (CDR) will be used to recruit participants. The participants will be recruited in this study CDR score varies from 1 to 4, and MMSE >=18. Other inclusion criteria are complain of conscious cognitive decline, participate voluntarily and sign informed consent. However, potential participants will be excluded if they diagnosed with moderate or severe dementia, those who have received cognitive training or motor training within six months, people with severe sensory function impairment (such as vision, hearing), and with limited mobility, such as those using wheelchairs or four-legged walking aids.

Randomization and Blinding: The allocation of the group to be either the experimental (dual-task training group, cognitive training group, motor training group) or control group will be conducted using permuted block randomization design with a block size of four. Randomization was carried out using a web-based randomization tool by a third party who was not involved in the intervention team. To ensure the allocation concealment, investigators use SNOSE principle (sequentially numbered, opaque, sealed envelopes), and randomization code will not be released until the participant or interventionist has started the trial. This study adopts a single-blind approach, by blinding data collector.

Baseline Data Collection Procedure: Participants who meet the inclusion criteria and agree to participate, will be requested to complete a sociodemographic characteristic questionnaire and the seven outcome measures. However, the completion of the seven outcome measures will be conducted in two days to avoid boredom among the participants. In the first period, a sociodemographic questionnaire, WCST, DS, NPI-Q will be completed. The PSQI, ISI, SFBBS, Chair sit-and-reach test (CSR) and Back scratch test completion will be conducted later in the second day at a time agreed upon by the researcher and participants.

Intervention delivery: 1). The dual-task training is a combination of cognitive tasks and motor tasks. Motor task consist of six components, including: strength, balance, agility, gait, aerobic capacity, and flexibility. Whereas Cognitive task consists of four cognitive domains: attention, executive function, learning and memory, language, and perception motor. Both component will be delivered simultaneously or at the same time, and will be delivered in a group format, consisting of 8 to 10 participants for each group. The length of therapy is 12 weeks; sessions are 3 times per week, each session lasts 45 minutes (20 minutes first: cognitive tasks and motor tasks, 5 minutes break time (at this time, participants will be given drink and snack), 20 minutes second: cognitive tasks and motor tasks), and total sessions are 36. In this study, only one interventionist (the principal investigator) from the research team will deliver the intervention sessions. The detail description of each session are below: session 1-6: Participants initially receive one of two tasks (either a cognitive or motor task) and undergo training for each individually; session 7-12: participants receive cognitive and motor task at the same time; session 13-18: repetition of sessions 7 to 12, and session 19-36 are repetition from session 1 to 18. 2). Cognitive training= in this group, participants only receive cognitive training. 3). Motor training= in this group, participants only receive motor training. The duration are same with dual-task training.