P2‐069: Central auditory processing in individuals at risk for Alzheimer's dementia
Bibliographic record
Abstract
Increasingly, therapeutic efforts in Alzheimer's disease (AD) are focusing on intervention at pre-symptomatic stages to defer onset of dementia. Progress of pre-symptomatic disease may be revealed by trajectory of AD biomarkers over time. These marker trajectories may therefore be used both to identify persons at risk of subsequent symptoms and to evaluate efficacy of candidate preventive treatments. Central processing of complex auditory stimuli (Central Auditory Processing, or CAP) is impaired in AD dementia and MCI. In cognitively normal (for age) older persons, CAP impairment has also been shown recently to identify a nine-fold increase in risk of subsequent dementia (Gates, 2011). Here we explore CAP as a potential biomarker of pre-symptomatic AD. To do so, we first investigated the relationship of CAP and age. We then questioned whether this relationship differed according to presence of an e4 allele at APOE, which substantially elevates an individual's risk of AD dementia. Participants (n=63) with a first-degree family history of AD were screened for cognitive disorder using the Montreal Cognitive Assessment (>24), the Clinical Dementia Rating Scale (CDR=0), and (subsequently) a 45-minute psychometric battery. Subjects were tested using the Synthetic-Sentence-Identification-with-Ipsilateral-Competing-Message (SSI-ICM) task. This test measures ability to recognize speech in the presence of competing background noise, a key feature of CAP. We analyzed data from 57 individuals who passed a screening examination for pure-tone hearing. SSI-ICM score was inversely related to age, as expected. This was determined via robust fit regression (r2=0.154, p=0.0015). However, segregation of groups by APOE e4 status showed that age predicted test scores only for those with e4 (r2=0.442, p=0.0004; for e4-negative, r2=0.0614, p=0.165). After analysis for rate of change using a two-sample t-test, we observed a trend toward greater decline in SSI-ICM score with age among those who were APOE e4+ (t=1.48, p=0.07).
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".