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    "story_id": "mp-2026-08-13-010",
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    "headline": "Forty-Nine Thousand Brains Built a Reusable Starting Point",
    "slug": "forty-nine-thousand-brains-built-a-reusable-starting-point",
    "dek": "GenFAR trained a general MRI representation across eleven cohorts and seventeen tasks, then transferred it to new prediction problems.",
    "summary": "GenFAR trained a general MRI representation across eleven cohorts and seventeen tasks, then transferred it to new prediction problems.",
    "body_text": "The framework trained on MRIs from 49,246 people across 11 cohorts, using 17 tasks spanning cognition, diagnosis, demographics and biomarkers. An analysis of 5,000 task orderings selected six-task sequences and identified five strong donor tasks, including age and cognitive measures. The resulting representation improved accuracy and sample efficiency on secondary tasks not included in the original sequence. These are retrospective modeling results, not a clinical diagnostic system or evidence that one representation fits every population.",
    "why_it_matters": "GenFAR trained a general MRI representation across eleven cohorts and seventeen tasks, then transferred it to new prediction problems.",
    "limitations": [
      "The resulting representation improved accuracy and sample efficiency on secondary tasks not included in the original sequence.",
      "These are retrospective modeling results, not a clinical diagnostic system or evidence that one representation fits every population."
    ],
    "importance": 8,
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    "first_published_at": "2026-08-13T09:00:00.000-04:00",
    "modified_at": "2026-08-13T09:00:00.000-04:00",
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    "tags": [
      "brain MRI",
      "foundation models",
      "medical imaging"
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  "sources": [
    {
      "source_id": "source-2026-08-13-010",
      "title": "arXiv preprint 2608.12185",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2608.12185",
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      "source_type": "primary_research",
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      "published_at": "2026-08-12T11:40:29.000-04:00",
      "accessed_at": "2026-08-13T08:18:00.000-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "Forty-Nine Thousand Brains Built a Reusable Starting Point",
    "publisher": "The Machine Press",
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