The Effectiveness of Dual Task Training in Elderly With Cognitive Decline

Cognitive decline is the impairment of memory, execution, or language. Early detection of the individuals who manifest cognitive decline and provide appropriate interventions may help reduce the burden of their caregivers and the medical expenses of the health-care system. Many studies have found that dual-task training combining cognitive training and exercise can improve cognitive function in older adults. However, it is yet not clear the appropriate frequency of the effective dual-task training for elderly with cognitive decline. Thus, this study aims to compare the intervention effects of high frequency sequential and low frequency dual-task training for elderly with cognitive decline.

Cognitive decline is the impairment of memory, execution, or language. Early detection of the individuals who manifest cognitive decline and provide appropriate interventions may help reduce the burden of their caregivers and the medical expenses of the health-care system. Many studies have found that dual-task training combining cognitive training and exercise can improve cognitive function in older adults. However, it is yet not clear the appropriate frequency of the effective dual-task training for elderly with cognitive decline. Thus, this study aims to compare the intervention effects of high frequency sequential and low frequency dual-task training for elderly with cognitive decline. We anticipate recruiting a total of 80 participants with cognitive decline. The participants will be assigned into 2 groups: high frequency dual-task training (HF) and low frequency dual-task training (LF) groups. The participants of HF will receive a total of 36 training sessions, and each session will contain 90-120 minutes of training. The participants of LF will receive a total of 12 training sessions, and each session will contain 90-120 minutes of training. The programs are based on dual-task trainings which contain cognitive training and exercise simultaneously. For physical exercise, we will design the programs that involve balance or strength training components in the aerobic exercises. In terms of cognitive training, we will design self-made teaching aids and board games to train different domains of cognitive functions. We plan to assess the participants before and after the intervention programs. We expect that elders receiving dual-task training will improve on outcome measures, and the group with more frequency will have better performance. The results of the study will provide evidence of interventions for elderly with cognitive decline, thereby reducing the burden on their caregivers and the cost of medical resource.

The participants of HF will receive a total of 36 training sessions, and each session will contain 90-120 minutes of training.

The participants of LF will receive a total of 12 training sessions, and each session will contain 90-120 minutes of training.

The programs are based on dual-task trainings which contain cognitive training and exercise simultaneously. For physical exercise, we will design the programs that involve balance or strength training components in the aerobic exercises. In terms of cognitive training, we will design self-made teaching aids and board games to train different domains of cognitive functions. We plan to assess the participants before and after the intervention programs. We expect that elders receiving dual-task training will improve on outcome measures, and the group with more frequency will have better performance. The results of the study will provide evidence of interventions for elderly with cognitive decline, thereby reducing the burden on their caregivers and the cost of medical resource.

The Montreal Cognitive Assessment (MoCA) was designed as a rapid screening instrument for mild cognitive dysfunction. It assesses different cognitive domains: attention and concentration, executive functions, memory, language, visuoconstructional skills, conceptual thinking, calculations, and orientation. Time to administer the MoCA is approximately 10 minutes. The total possible score is 30 points; a score of 26 or above is considered normal.

The Mini-Mental State Examination (MMSE) is the most commonly administered psychometric screening assessment of cognitive functioning. The MMSE is used to screen patients for cognitive impairment, track changes in cognitive functioning over time, and often to assess the effects of therapeutic agents on cognitive function. The total score of MMSE ranged from 0 to 30. Higher values represent a better cognitive functioning.

The Stroop test will be used to assess the processing speed, inhibition, set-shifting, and selective attention abilities. The participants will be tested under 2 conditions: congruent and incongruent conditions. In the congruent condition, the color ink of a word is consistent with the written color name; while the color ink differs from the written color name under the incongruent condition.

The TUG test will be used to assess the mobility and dynamic balance ability. The participants will be required to stand up from a chair, walk 3 meters, turn around, then walk back to the chair, and sit down. The time to complete the TUG test has been shown to be a good indicator to detect potential fallers and frail elderly (Podsiadlo & Richardson, 1991). The test-retest reliability of TUG on individuals with cognitive impairment was excellent.

The dual-task tests will be assessed to determine the ability for an individual to perform 2 tasks simultaneously. The investigators will assess the dual-task performance during walking and performing box and block test. The results of the dual-task tests will provide information regarding to whether the 2 tasks compete for the same class of neural resources or one of the tasks can be carried out automatically

Subtests of the Wechsler Adult Intelligence Scale (WAIS) will be used to measure the cognitive functions of an individual. The WAIS have high reliability and validity, and is often used to differentiate individuals with cognitive deficits and those with intact cognitive functions. In addition, WAIS could be used to assess cognitive improvements after an intervention or treatment.

Assess activities of daily living. There are 8 domains of function measured with the Lawton IADL scale, including ability to use phone,shopping, food preparation, housekeeping, laundering, mode of transportation, responsibility for own medications,and ability to handle finances. A summary score ranges from 0 (low function, dependent) to 8 (high function, independent). For each category, circle the item description that most closely resembles the client's highest functional level (either 0 or 1).

The Wechsler Memory Scale (WMS) was designed to measure different memory functions. The subtests, including Word Lists, and Spatial Span will be used to assess the immediate, delayed, and working memory. Time to administer the WMS subtests is approximately 45 minutes. The total scores range from 0-48 for the immdiate memory, and 0-24 for the delayed memory. Higher values represent a better cognitive functioning.

The social participation level will be assessed with the Community Integration Questionnaire (CIQ).It contains 15 items to evaluate the degree of integration into each of the three area of family, social network, and productive activities. The total scores range from 0 to 29 with larger numbers indicating better integration.

The Geriatric Depression Scale (GDS) - 15 items version is a self-administered questionnaire used to evaluate mood and depressive symptoms. The scores range is 0-15 and a score of 5 or greater taken as a possible indicator of depression.

To detect cognitive and functional decline. The ECog shows promise as a useful tool for the measurement of general and domain-specific everyday functions in the elderly. There are six domains (Everyday Memory, Language, Visuospatial Abilities, Planning, Organization, and Divided Attention) in ECog. Lower scores represent a higher level of function in daily life.

Inclusion Criteria: able to follow instruction (MMSE>= 20) self- or informant-reported memory or cognitive complaint. Exclusion Criteria: recent myocardial infarction,heart failure,recent heart surgery, severe asthma, concomitant with other neurological disorders, or joint deformity that might prevents them performing exercise or cognitive training.