Oushana, L. | Search bioRxiv

bioRxiv2026

Limited Volumetric Separation Across CDR Groups in OASIS-1

Clinical Dementia Rating (CDR) scores are used to classify the cognitive state of patients and are provided within neuroimaging datasets. This is achieved through a standardized clinical assessment that evaluates participants cognitive and functional abilities in everyday life, after which they are given a score ranging from 0 to 3. Where 0 represents no signs of dementia and three represents severe dementia1. These scores are then used to track the progression of dementia over time2. This study explored if these CDR labels within the OASIS-1 dataset produced consistent volumetric separation across the hippocampus, amygdala, and cortex.

neuroscience↗

bioRxiv2025

Posterior Cortex Isolation Enhances Detection of Alpha Desynchronization During Sustained Attention

Electroencephalography (EEG) is an essential tool for assessing the neural activity behind mental fatigue, a factor that can influence both cognitive and physical performance. Mental fatigue influences alpha-band oscillations (8-12 Hz), reflecting cortical engagement and attention stability. In this study, EEG recordings from 109 participants in the Physionet open-source EEG Motor Movement/Imagery Dataset (EEGMMIDB) were analyzed to characterize alpha power changes during sustained attention. Spectral analysis was performed across early and late task blocks to quantify alpha desynchronization over time. Participants demonstrated a consistent decrease in alpha power ({Delta} = -0.076 {+/-} 0.019 log10 units; p = 0.0001), indicating desynchronization associated with sustained attentional demand. These findings show the applicability of open-source EEG datasets for research. Furthermore, these findings support the isolation of posterior activation as a marker of mental fatigue through alpha desynchronization. One sentence overviewAlpha desynchronization is a marker for mental fatigue in EEGs. This paper illustrates that isolating the posterior cortical lobes enhances the resolution and sensitivity of alpha band changes associated with sustained attention.

neuroscience↗