Nearly 14 million people are projected to develop Alzheimer's disease (AD) by 2050 in the USA alone, with those affected by mild cognitive impairment (MCI) being especially at risk. Therefore, interventions aimed at prevention of dementia and promotion of brain and cognitive health in older adults need to be developed. One of the most successful types of non-pharmacological intervention is cognitive training, where participants engage in mental exercises targeting one or multiple cognitive domains. A recent meta-analysis has found that both healthy older adults and older adults affected by MCI, benefit equally in cognitive health from such training. Importantly, both populations showed improvements in cognitive abilities that were beyond the trained skills, such as everyday cognition, suggesting that cognitive training has a broad impact on independence in daily activities and quality of life. The training of attentional control has proven to be the most effective type of single-component training. Attentional control is the ability to focus attention to a task while inhibiting distractors; this "core" ability is fundamental for many everyday tasks. In addition to directly training attentional control, another promising approach to reducing distractibility is mindfulness meditation. As for the neural effects of attentional control training and meditation training, alterations in resting state brain function are reported, esp. in Default Mode Network (DMN) regions that are related to memory and attentional control. DMN is found to be engaged in older adults, but is disengaged in younger adults; this overactivation is detrimental to cognitive performance. However, the combined benefits of cognitive control training and mindfulness meditation on cognition and DMN are understudied in older adults.

In this project, there is a single training arm that will train healthy older adults on a combination training composed of high attentional control and mindfulness meditation using simulation based games. Neural and cognitive changes in near and far transfer tasks will be examined immediately after the intervention. These changes will be compared with that of a previously collected group of older adults who received only cognitive control training (NCT03988829; Arms 1 and 2). Changes in overall cognition (primary cognitive outcome) and changes in DMN connectivity during task (primary neuroimaging outcome) and rest (secondary neuroimaging outcome) in this combination training group will be compared to the respective changes in Arm 1 (low attentional control training) and Arm 2 (High Attentional Control training) of the existing dataset. The protocol of participant recruitment, pre- and post- training assessments (MRI and behavioral), and training platform remain same between this study and the existing database. In this current study, participants also undergo a functional near infra-red spectroscopy (fNIRS) session, after completion of behavioral and MRI session, at pre-training and post-training. This clinical trial will result in the development of more efficient behavioral intervention tools in older adults, based on neuroimaging evidence, that can be readily used from the comfort of home.