Imbalance, compensation, and rigidity in brain functional connectivity and microstates among older adults with cognitive impairment
Bibliographic record
Abstract
OBJECTIVE: This study seeks to analyze the coordinated patterns of spontaneous neural activity and instantaneous electrical activity in the brain using dual-dimensional indicators of brain functional connectivity and microstates, aiming to identify potential biomarkers for early screening and precise classification. METHODS: A case-control study design was utilized, with 195 older adults suffering from cognitive impairment (with a roughly equal distribution of mild and moderate cases) serving as the case group, and 65 healthy older adults matched as the control group. Participants were required to complete a demographic questionnaire, the Montreal Cognitive Assessment Scale, the short form of the International Physical Activity Questionnaire, and the Pittsburgh Sleep Quality Index, after which 5 min of eyes-closed resting EEG signals were recorded. RESULTS: Significant differences were observed in the average strength and density of brain functional connectivity within the δ and θ frequency bands among older adults with different cognitive levels, indicating that higher average strength and density corresponded to more severe cognitive impairment (P < 0.05). Older adults with varying cognitive levels showed significant differences in both static features (Duration, Coverage, Occurrence) and dynamic features (transition probabilities) of microstates A, B, C, and D (P < 0.05). In terms of static features, stronger temporal characteristics of microstates B and D were associated with greater severity of cognitive impairment, while microstate A demonstrated the most pronounced temporal characteristics during the mild cognitive impairment stage (P < 0.05). In dynamic features, healthy older adults primarily exhibited bidirectional balanced transitions between A/C↔C/A and B/D↔D/B, while those with mild cognitive impairment displayed transitional characteristics in the paths A→B/D and C→D. In contrast, older adults with moderate to severe cognitive impairment showed significantly enhanced directed transitions from microstates B/D to A/C (P < 0.05). CONCLUSION: Older adults with mild cognitive impairment demonstrated increased abnormal and redundant brain functional connectivity, inefficiency in microstate C, and compensatory mechanisms in low-frequency connectivity in brain functions as well as microstates A, B, and D. Older adults with moderate to severe cognitive impairment displayed sustained compensatory mechanisms in brain functional connectivity and microstates, characterized by dominant abnormal and redundant connections, along with pathological hypersynchrony in microstates B and D, which persisted until rigidity set in.
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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 | 0.002 |
| 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".