Multiscale Dispersion Entropy of Resting‐State EEG in Older Adults with Alzheimer's Dementia, Mild Cognitive Impairment, or remitted Major Depressive Disorder
Bibliographic record
Abstract
BACKGROUND: Multiscale dispersion entropy (MDE) is a nonlinear approach for assessing the complexity of brain activity using electroencephalograms (EEGs). MDE captures EEG dynamics across biologically relevant time scales, with short-scales reflecting high-frequency oscillations and local neuronal activity, and long-scales representing low-frequency oscillations and large-scale network processes. Previous studies suggest that patients with Alzheimer's dementia (AD) have decreased complexity at short time scales compared to those with mild cognitive impairment (MCI) or healthy controls (HCs), and individuals with MCI show reduced complexity compared to HCs. There is also preliminary evidence suggesting that adult patients with acute depression -a high-risk condition for AD- have decreased complexity at a short time scale. Thus, we conducted a study in older participants with AD, MCI, HC, remitted major depressive disorder (rMDD), or rMDD+MCI, hypothesizing reduced short-scale MDE in AD vs. MCI and MCI vs. HC. We also explored MDE at short and long time scales across all diagnostic groups and their relationships with cognitive performance. METHOD: The study included 44 HC, 46 rMDD, 114 MCI, 71 rMDD+MCI, and 41 AD participants. MDE was generated using resting-state EEG with 24ms as the short time scale and 60ms as the long time scale. Cognition was assessed using the Montreal Cognitive Assessment and a cognitive composite score from a comprehensive neuropsychological battery. RESULT: MDE at 24ms was decreased in AD vs. MCI and in MCI vs. HCs. rMDD had no impact. At 60ms, only the AD group differed from the other groups. Cognitive performance was associated with MDE at 24ms but not 60ms. CONCLUSION: This study highlights the value of MDE at a short time scale, related to local neuronal activity, to separate individuals with AD vs. MCI vs. HCs. Reduced complexity in these individuals may underlie their cognitive impairment. In contrast, our study suggests that any MDD impact on complexity is likely related to active depressive symptoms.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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 source (direct Gemma or distilled Codex), 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".