0961 Range And Reproducibility Of EEG Biomarkers For Cognition Across Five Years.
Bibliographic record
Abstract
Multiple EEG markers are reported to associate with cognition and/or cognitive decline, including spindle frequency, and alpha-intrusion. Also, at similar technical settings amplitude of the EEG signal varies considerably across individuals, and an index that describes the extent of this natural amplification (overall power) was also identified as a risk factor for dementia. Here, we determined the range and reproducibility of these features over five years in a community-based sample. We utilized algorithms available in a commercial scoring system to determine EEG features in 2,647 subjects of the Sleep Heart Health Study who underwent baseline and follow-up polysomnography approximately 5 years apart. Spindles are identified using a validated detector. Their characteristics are expressed as density (sum of spindles in C3 and C4 per minute of NREM stage 2), duration (seconds), peak power (μV2), and dominant frequency (Hz). Alpha intrusion is percent of 3-second NREM epochs with alpha power >30 μV2. Overall power is the average of 7 ratios representing ratios of power in 7 frequency ranges in the subject to average power in the corresponding ranges in the entire cohort. Intra-class correlation coefficients (ICC) were calculated to evaluate feature reproducibility between baseline and follow-up. Average (Range: 5th- 95th percentile) of spindle characteristics at baseline were: Density 4.6/minute (0.8-10.2); Duration 1.33 second (1.25-1.43); Peak power 28.9 μV2 (15.6-47.0); Dominant frequency 12.0 Hz (11.1-12.9). After 5 years, density decreased 0.31±0.79/minute, power decreased 1.2±5.9 μV2, frequency decreased 0.2±0.4 Hz and duration increased 0.01±0.05 second (p<0.0001 for all). ICCs for spindle metrics were 0.83 for density, 0.63 for duration, 0.80 for power and 0.73 for frequency. Alpha intrusion index was 4.1% (0-18) at baseline, decreased 0.1±4.8% after 5 years and ICC was 0.83. Overall EEG power was 0.87 (0.47-1.44) at baseline with no significant change after 5 years and ICC was 0.77. Spindle characteristics, alpha intrusion index and overall EEG power vary over very wide ranges among individuals but show high within individual correlations across 5 years, suggesting “trait-like” properties. AASM Foundation (194-SR-18), NHLBI R24 HL114473
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".