0079 Preliminary Analysis Reveals Link Between Visual Attention and Sleep Duration in Alzheimer's Disease

Abstract Introduction Sleep disturbances have been shown to relate to the development of Alzheimer’s disease (AD) and its associated cognitive deficits, including visual attention function. Here, we investigated the potential interactive and additive effects of sleep disruption and AD on visual attention performance and its underlying neural mechanisms. Methods Preliminary analysis included 33 participants, 10 patients on the AD spectrum (mild cognitive impairment (MCI) and AD; 7 females; Mage: 70.24) and 23 cognitively-healthy older adults (17 females; Mage: 67.47). Participants completed a visual search task during magnetoencephalography (MEG). Participants also wore an Actigraph device on their non-dominant wrist for a two-week period. Actigraph data were cleaned using sleep diaries and analyzed using the Cole-Kripke algorithm. Total sleep time (TST) was calculated for each night of sleep and averaged across all nights of sleep collected. The MEG data were transformed into the time-frequency domain and significant task-related oscillatory responses were source-imaged using a beamformer. Results Behavioral analysis of the visual search task revealed a significant condition effect, such that reaction times (RT) in the conjunctive trials were significantly longer than those in the feature condition (p .001). There was a trending group-by-condition interaction on RT (p = .080), such that patients on the AD spectrum showed larger differences in reaction times between conditions than healthy controls. Additionally, there was a significant group by TST interaction on RT (p .001) showing that patients on the AD spectrum with less sleep had longer RT, while there was no such relationship in the controls. Regarding the MEG data, we observed robust neural responses in theta, alpha, and beta frequency bands. Analysis of source-imaged neural responses in the alpha range revealed significant conditional differences in the right posterior temporal lobe (p .005), a significant group-by-condition interaction in the right temporoparietal junction (TPJ; p .005), and interestingly, a group-by-TST interaction on conditional differences in alpha power (p .005) in right occipital and cerebellar regions. Conclusion Our preliminary results show key relationships between total sleep time, visual attention behavioral performance, and neural recruitment, and how these relationships may differ in AD spectrum conditions. Support (if any) R01-MH116782, R01-MH118013