## Plan: A1 SI Baseline with Protocol C Evaluation and Expanded Parcels

Implement A1 as a frozen SI baseline with Protocol C cross-subject shared-space evaluation. Keep both 7 language ROIs and expanded Harvard-Oxford symmetric parcels, and report results by fold and run condition.

**Steps**
1. Phase 0: Paper-first gate before coding
- Verify appendix details for ROI/parcellation and document any unresolved ambiguities.
- Lock assumptions and scope before implementation starts.

2. Phase 1: Data manifest and integrity QC
- Build clean derivatives manifest with strict checks: folder and filename subject consistency, run whitelist 1-4, sidecar existence, unique subject-run keys.
- Save reject log and accepted manifest.
- Validate per-run TR and scan length from BIDS sidecars.

3. Phase 2: Spatial harmonization and mask
- Resample BOLD to one canonical analysis grid.
- Build analysis mask and enforce left-right symmetry using hemisphere swap and mask intersection.
- Emit affine and shape and voxel-count QC report.

4. Phase 3: Target definition with two parcellation tracks
- Track A: 7 language ROIs from sphere masks.
- Track B: Harvard-Oxford cortical maxprob-thr0-2mm with symmetric split for expanded parcel analysis.
- Resample labels with nearest-neighbor interpolation only.
- Build left-right parcel pairing map and parcel voxel index map.

5. Phase 4: Annotation harmonization
- Build unified word-event table with run_id, condition, speaker_stream, word, onset_s, offset_s, duration_s, provenance.
- Apply approved fixed run mapping and mixed-run fallback flags.
- Validate monotonic and non-negative timing.

6. Phase 5: Frozen SI feature extraction
- Extract per-run, per-layer, per-word hidden-state features for approved models.
- Cache token-to-word aggregated embeddings and extraction metadata.
- No model fine-tuning in baseline phase.

7. Phase 6: Temporal alignment and normalization
- Convert word features to TR regressors with HRF convolution.
- Apply per-run z-score to regressors and BOLD targets.
- Enforce exact regressor-target TR length match after trimming policy.

8. Phase 7: Evaluation implementation (required)
- Protocol C: cross-subject shared-space split
- Use 21:3 subject split with 2-fold cross-validation over accepted subjects.
- Keep fold construction deterministic via a fixed seed.
- Compute metrics for both target sets: 7 ROIs and expanded parcels.
- Keep outputs clearly labeled by fold and run condition.

9. Phase 8: Outputs and reporting
- Save per-model, per-layer, per-subject, per-run, per-target, per-protocol tables.
- Save left-right asymmetry summaries and significance tables for parcel and ROI levels.
- Save Protocol C summary report across folds and run conditions.

10. Phase 9: Optional extension after baseline
- Add fine-tuning branch as a separate experiment only after frozen baseline is complete.
- Compare against frozen baseline outputs using matched protocols.

**Relevant files**
- /home/mohith/ds005345/NeurIPS-2024-fmri-predictors-based-on-language-models-of-increasing-complexity-recover-brain-left-lateralization-Paper-Conference.pdf — paper and appendix reference gate.
- /home/mohith/ds005345/llms_brain_lateralization/README.md — reference pipeline order and 7 ROI context.
- /home/mohith/ds005345/llms_brain_lateralization/create_roi_masks.py — 7 language ROI coordinates and generation pattern.
- /home/mohith/ds005345/llms_brain_lateralization/analyze_results.ipynb — expanded Harvard-Oxford symmetric atlas workflow and nearest-neighbor resampling pattern.
- /home/mohith/ds005345/llms_brain_lateralization/extract_llm_activations.py — hidden-state extraction and token-to-word aggregation pattern.
- /home/mohith/ds005345/llms_brain_lateralization/fit_individual_subject.py — run-wise HRF regressor build and ridge CV template.
- /home/mohith/ds005345/llms_brain_lateralization/resample_fmri_data.py — canonical resampling pattern.
- /home/mohith/ds005345/llms_brain_lateralization/compute_mask.py — symmetric mask computation.

**Verification**
1. Paper gate checks
- Appendix ROI and parcel assumptions logged and aligned with implementation choices.

2. Spatial checks
- Atlas and BOLD match analysis affine and shape.
- Label interpolation nearest-neighbor only.
- Symmetric mask voxel counts and left-right balance logged.

3. Feature checks
- Hidden-state files complete for each run, model, and layer.
- Token-to-word aggregation diagnostics saved.

4. Modeling checks
- Frozen baseline confirmed with no weight updates.
- Protocol C fold table uses 21 train and 3 test subjects per fold with 2 folds.
- Each canonical run condition is evaluated per fold.

5. Reporting checks
- 7 ROI and expanded parcel outputs exist for both protocols.
- Side-by-side protocol comparison produced for every model.

**Decisions**
- Baseline SI uses frozen inference plus ridge only.
- Protocol C cross-subject shared-space is the required baseline evaluation protocol.
- Random word-level 500/100 split is excluded from primary SI evaluation due temporal leakage risk after HRF convolution.
- Expanded ROI set uses Harvard-Oxford cortical maxprob-thr0-2mm with symmetric split.
- Fine-tuning remains a separate post-baseline experiment branch.

## Running On HF Jobs

For this project, use HF Jobs rather than a Space. The A1 pipeline expects one root containing:

- `project/`
- `data/`
- `derivatives/`

The launcher in `project/hf_jobs.py` reconstructs that layout inside the HF container and then runs `project/code/run_a1_end_to_end.py` unchanged.

### Required HF repos

Create two HF Dataset repos:

- one whose repo root mirrors the contents of local `data/`
- one whose repo root mirrors the contents of local `derivatives/`

Important:

- upload the folder contents, not the parent folder name
- the `data` repo should have files like `participants.tsv` and `sub-01/` at repo root
- the `derivatives` repo should have `sub-01/`, `sub-02/`, ... at repo root

### Preview The Job

```bash
cd /home/mohith/ds005345
conda activate csai
python project/hf_jobs.py \
  --code-url https://huggingface.co/spaces/Mohith202/csai.git \
  --data-repo Mohith202/ds005345-data \
  --derivatives-repo Mohith202/ds005345-derivatives \
  --results-repo Mohith202/ds005345-a1-results \
  --secret-hf-token
```

This prints the generated job script and the `hf jobs run` command without launching it.

### Launch The End-To-End Run

```bash
cd /home/mohith/ds005345
conda activate csai
python mohith/TEAM-9/hf_jobs.py \
  --code-url https://huggingface.co/spaces/Mohith202/csai.git \
  --data-repo Mohith202/ds005345-data \
  --derivatives-repo Mohith202/ds005345-derivatives \
  --results-repo Mohith202/ds005345-a1-results \
  --results-path hf_jobs/run_001 \
  --flavor a10g-small \
  --model-profile current \
  --protocols C \
  --secret-hf-token \
  --launch
```

### Notes

- `--secret-hf-token` is recommended when the dataset repos are private.
- The job keeps the CUDA-enabled PyTorch already present in the container image and installs the rest of `project/requirements.txt` separately.
- By default bootstrap artifacts go to `outputs/a1_bootstrap_hf` inside the cloned repo.
- You can forward the normal end-to-end controls such as `--model-profile`, `--model-slug`, `--protocols`, `--reuse-caches`, `--skip-bootstrap`, `--skip-fit`, and `--skip-visualize`.