| --- |
| license: mit |
| task_categories: [feature-extraction] |
| tags: [brain-alignment, fmri, rsa, developmental, null-result] |
| --- |
| |
| # Lytle et al. (2020) — LM brain-alignment results |
|
|
| Language-model / fMRI representational-alignment results for **Lytle et al. (2020)**: |
| orthographic, phonological and semantic word processing in school-aged children (8.7-15.5), auditory and visual |
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|
| OpenNeuro accession **`ds002236`** · cohort: school-aged children, ages 8.7-15.5 · modality: auditory and visual |
| · tasks: Phon, Sem · cells: 6 · rows: 924 |
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|
| Layout follows [`BrainAlign/cdl-devai-results`](https://huggingface.co/datasets/BrainAlign/cdl-devai-results): |
| `by-model/<family>/{brain_alignment,checkpoints}.csv`, `overall/`, |
| `ceiling-analysis/`, `provenance_tier_ledger.json`. |
|
|
| ## Result: alignment is not distinguishable from a random seed |
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|
| 5 trained families (pythia-1.4b-full, pythia-160m-full, pythia-1b-full, pythia-410m-full, pythia-70m-full) and 9 PARC noise-seed |
| baselines, scored identically. Cells where a real family exceeds all 9 noise |
| seeds: **0 of 30**, against **3.0 expected by chance**. |
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|
| Pooled across all three developmental datasets: 9/130 observed vs 13.0 expected |
| (p = 0.91); per-cell means of real families vs noise seeds correlate at |
| **r = +0.863**; **83.9%** of variance is cell identity and **3.2%** model family. |
|
|
| ## Interpretation |
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|
| These RDMs have real inter-subject reliability (noise ceilings in |
| `ceiling-analysis/ceilings.csv`), but the upstream pipeline's **positive controls |
| fail on this dataset**. The claim supported here is *"no LM alignment is |
| detectable by this measurement"* — **not** "language models do not align with the |
| developing brain." Read this as a result about the benchmark. |
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|
| Negative results are published here deliberately: the per-cell nulls and the |
| noise-seed baselines are the reusable part. |
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|
