2.1 Participants
The study included three groups of participants including younger adults [YA] (Total N = 29, 11 males, mean age of 21.3 ± 2.5 years, mean education of 14.2 ±1.2 years), cognitively healthy older adults [HA] (total N = 22, 5 males, mean age of 63.9 ± 6.4 years, mean education of 17 ± 1.6 years), and individuals with a diagnosis of mild cognitive impairment [MCI] (total N = 20, 10 males, mean age of 67.8 ± 8.2 years, mean education of 16 ± 2.4 years; Clinical Dementia Rating of 0.5). All participants were native English speakers with no history of learning disabilities, stroke, major psychiatric illness, alcoholism or substance abuse, or uncorrected hearing or vision loss. All MCI participants met Petersen criteria (Petersen et al., 2009), by consensus diagnosis among clinicians or research investigators, including the following: (1) cognitive concerns reported by the patient and/or corroborated by a reliable informant, (2) cognitive impairments verified by objective measures, (3) relative independence in performing daily functions, and (4) did not meet dementia criteria. Both amnestic (N = 16) and non-amnestic (N = 4) MCI patients were included. The HA and MCI groups had no statistical differences in age and education. Performance on selected neuropsychological tests for HA and MCI is presented in Table 1. Informed consent was obtained from all participants in accordance with the protocols approved by the Institutional Review Boards of The University of Texas at Dallas and The University of Texas Southwestern Medical Center. Experiments with participants were performed in accordance with the ethical standards of the Committee on Human Experimentation of these institutions and with the Helsinki Declaration of 1975.