Discussion
BRAIN, CORTEX
In this paper, we report intervention-related changes in rs-fMRI static functional connectivity in our Projecte Moviment trial, which investigates the potential neuroprotective effects of interventions (AE, CCT, COMB) in healthy physically inactive late-middle-aged adults compared to a healthy control group [In our study, the participants who followed the AE program showed positive changes in rs-fMRI functional connectivity in agreement with previous studies [For the CCT group, we reported an increased rsFC between the left hippocampus (pDMN) with the right inferior frontal gyrus (opercular part) (aDMN) and the right middle frontal gyrus (aDMN), between the right hippocampus (pDMN) with the left middle frontal gyrus (aDMN), and the left inferior frontal gyrus (opercular part) (aDMN), and between the left superior frontal gyrus (aDMN), with the left inferior parietal gyrus (pDMN). Previous studies in healthy older adults reported a combination of increased rsFC and decreased rsFC in the DMN as a consequence of a CCT program (for a review, see Ten Brinke et al. [Our study also evaluates the benefits of combining multimodal CCT and brisk walking for 12 weeks, 5 days per week in bouts of 54 min. Participants of the COMB group showed an improvement in both global and local rsFC compared to the control group. Our findings supported both the benefits of COMB intervention in terms of both local and global rsFC. The increment of global rsFC is a positive outcome of the COMB intervention by comparing the global mean of our group of old adults compared to the global mean of younger adults from the NYU dataset (see supp. material Table DMN are defined as sets of anatomically distance brain areas that showed temporal correlations of their spontaneous resting-state fluctuations which is called functional connectivity [Despite the growing amount of accumulated knowledge regarding the physiology and anatomy of DMN, the main cognitive function of this network is still poorly understood. Different parts of DMN are involved in different high-level cognitive functions. For example, the posterior cingulate cortex (PCC) is active during tasks that are associated with autobiographical episodic memory and self-referential processes [The DMN consists of cortical brain areas that are anatomically distant from input to output systems of the brain in visual and motor cortex. Previous findings suggest that the DMN consists of brain areas that are on the top of a representational hierarchy that involves the cognitive landscape of abstract terms. These terms revealed by a meta-analysis of published research articles are the “social cognition,” “verbal semantics,” and “autobiographical memory”—tasks that rely on complex representations abstracted away from specific sensory and motor processes [Mean rsFC in the whole-brain and within the DMN showed a nonlinear trajectory in healthy older adults with more rapid declines in older age and a possible increment in early stages of the aging process (Staffaroni et al., 2018). This study investigated how rsFC changes within the age spectrum (55–90 age) in normal aging in three DMN subnetworks: (1) within-DMN, (2) between anterior and posterior DMN, and (3) between medial temporal lobe network and posterior DMN. The partition of DMN in anterior and posterior parts has been previously reported in the literature [RsFC within the DMN is the most common resting-state network under investigation that has been also found to be impacted by aging [Neuroimaging findings from various task-evoked activity studies have isolated brain areas of the dorsal frontal and posterior parietal cortex to be involved in the direction of attention to spatial locations [Brain networks involved in primary information processing such as the visual network (VN) showed within-network connectivity significant positive association with older age [In moderation analyses, we did not find a significant moderation effect of age on intervention-related changes in the global mean rsFC strength estimated over the individual sFCN in any groupTo reveal the possible mechanisms that could explain the cognitive benefits in the AE group in the Executive Function (Working Memory) and Attention-Speed (Attention) and in the COMB group in the Attention-Speed (Attention and Speed) [The failure of the mediation analysis with rsFC as actual mediators could be explained due to the short duration of the intervention and/or the sample size which might not be enough to reveal such mediation effects in the cognitive functions of high variability [While there is partial consistency in neuropsychological, and structural neuroimaging findings across the studies, results based on rsFC analysis are less consistent. The reason for this inconsistency is due to a large repertoire of available analytic paths that one researcher can follow. Below, we summarize the available rsFC options: the seed-based analysis targeting one or a few seed ROIs [