aRisk for developing AD was stratified in the Bertens et al. study by comparing patients with mild cognitive impairment who were classified as having AD pathology if their CSF Aβ1–42 level was below 192 pg/ml and higher risk to develop AD and mild cognitive impairment with lower risk of developing AD if their CSF Aβ1–42 level was below 192 pg/ml (see text [). Abbreviations: MMSE, Mini-Mental State Examination; ADAS-cog, Alzheimer’s Disease Assessment Scale–Cognitive; APOE ε4, apoliprotein E genotype and ε4 allele; CSF, cerebrospinal fluid; AD, Alzheimer’s disease; FDG-PET uptake, fluoro-d-glucose positron emission tomography uptake normalized.The wide variation in the rate at which patients with neurocognitive disorders progress, as discussed above, is due in part to risk factors that can be divided into two groups: nonmodifiable and modifiable. Nonmodifiable risk factors cannot be mitigated by diet or lifestyle changes and are part of an individual’s potential for developing a neurocognitive disorder. For example, the rate of AD is in part determined by nonmodifiable risk factors such as older age, female gender, and apoliprotein E genotype and ε4 allele. Just as important, epidemiological studies have shown that some modifiable factors can increase or decrease the risk of developing dementia. In a recent review, Cheng described physical activity—specifically, aerobic exercise—as a modifiable behavior associated with a decreased the risk of developing dementia (). Cheng pointed to the advantages of aerobic exercise in improving cerebrovascular and respiratory function; stimulating growth factors, particularly brain-derived neurotrophic factor; and decreasing oxidative stress and the inflammatory response (). In fact, a number of longitudinal studies support an association of physical exercise with increased hippocampal (), prefrontal, and cingulate cortex volumes (); a decreased risk of dementia for older adults (–); and a decrease in gray matter volume of patients with mild cognitive impairment or dementia (, )., Neurocognitive testing, also called neuropsychological testing, assesses a variety of cognitive skills, such as memory, visual and spatial skills, language and math skills, and problem-solving abilities. This article discusses neurocognitive function, factors that affect it, how it is tested, and how deficits are treated., Neurocognitive functions are cognitive functions closely linked to the function of particular areas, neural pathways, or cortical networks in the brain, ultimately served by the substrate of the brain's neurological matrix (i.e. at the cellular and molecular level)..