The accurate diagnosis of aging-related neurocognitive disorders as early as possible, even in a phase that is characterized by the absence of clinical symptoms, is nowadays the holy grail of the neurosciences. R4Alz-R is a novel cognitive tool designed to objectively detect the subtle cognitive changes that emerge as the very first result of the aging processes and could be developed and broadened in a continuum from healthy aging to subjective cognitive impairment (SCI) and mild cognitive impairment (MCI), before reaching some type of dementia. The goal of the present study was to examine whether the R4Alz-R battery has the potential to detect these subtle changes. The study sample comprised 184 people divided into (a) cognitively healthy young adults (HCya), (b) cognitively healthy older adults (HCoa), (c) people diagnosed with SCI, and (d) people diagnosed with MCI. The R4Alz-R comprises tests examining short-term memory storage, information processing, and updating of working memory, attention in different types of it, and main dimensions of executive functioning such as set-shifting, inhibitory control, and cognitive flexibility, as well as episodic memory. The flexibility and attention score showed an excellent potential to discriminate HCya from SCI (AUC 0.936, sensitivity 89.7%, specificity 88.4%). The executive functioning score almost excellently discriminated HCoa from SCI (AUC 0.898, sensitivity 87%, specificity 76.5%), while the fluid intelligence score had also an excellent potential to discriminate HCoa from MCI (AUC 0.953, sensitivity 85.7%, specificity 94.1%). The findings show that cognitive impairment in aging may start from the frontal lobe and prefrontal cortex, areas more closely related to cognitive control rather than memory. The lack of significant differences between HCya and HCoa proves that healthy older adults can keep their cognition at almost the same level as younger adults, a finding consistent with the new theoretical models regarding aging. The R4Alz-R battery is an innovative, free-of-demographic effect, valid, and reliable tool that can provide a highly accurate diagnosis of aging-related cognitive decline in its beginnings when it could still be possible to be reversed.
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