This file records the run metadata, preprocessing parameters, and quality-control results.
It’s designed to make your analysis reproducible, transparent, and easy to audit.
Processing Log Example Row
Below is an example entry from a processing log:| timestamp | study_user | run_id | proc_state | subj_basename | bids_subject | task | flags | net_nbchan_orig | net_nbchan_post | proc_badchans | proc_filt_lowcutoff | proc_filt_highcutoff | proc_filt_notch | proc_filt_notch_width | proc_sRate_raw | proc_sRate1 | proc_xmax_raw | proc_xmax_post | proc_xmax_percent | epoch_length | epoch_limits | epoch_trials | epoch_badtrials | epoch_percent | proc_nComps | proc_removeComps | exclude_category |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025-09-03 04:04:03 | unknown | 01K479NCMBQRRQ8QZTGB2CKWDN | completed_files | 128_Rest_EyesOpen_D1004 | sub-451559 | RestingStateTutorial | WARNING: 8 potential reference artifacts detected | 128 | 128 | [‘E56’, ‘E128’, ‘E8’, ‘E14’, ‘E17’, ‘E2’] | 1 | 80 | [60, 120] | 5 | 1000.0 | 250.0 | 303.4 | 44.0 | 0.145 | 2.0 | [-1, 1] | 29 | 7 | 0.758 | 121 | [0, 1, 2, 3, 4, 12, 15, 17, 18, 20, 21, 28, 34, 36, 49, 74] |
Processing Log Column Reference
| Column | Example Value | Description |
|---|---|---|
| timestamp | 2025-09-03 04:04:03 | Time when the run completed |
| study_user | unknown | User ID (or unknown if not set) |
| run_id | 01K479NCMBQRRQ8QZTGB2CKWDN | Unique identifier for this run |
| proc_state | completed_files | Status of the run |
| subj_basename | 128_Rest_EyesOpen_D1004 | Original recording file name |
| bids_subject | sub-451559 | BIDS subject identifier |
| task | RestingStateTutorial | Task or condition name |
| flags | WARNING: 8 potential reference artifacts detected | Warnings or notes from preprocessing |
| net_nbchan_orig | 128 | Channels in the raw input |
| net_nbchan_post | 128 | Channels after preprocessing |
| proc_badchans | [E56, E128, E8, E14, E17, E2] | List of bad channels removed |
| proc_filt_lowcutoff | 1 | High-pass filter cutoff (Hz) |
| proc_filt_highcutoff | 80 | Low-pass filter cutoff (Hz) |
| proc_filt_notch | [60, 120] | Notch filter frequencies applied (Hz) |
| proc_filt_notch_width | 5 | Width of notch filter (Hz) |
| proc_sRate_raw | 1000.0 | Original sampling rate (Hz) |
| proc_sRate1 | 250.0 | Resampled rate (Hz) |
| proc_xmax_raw | 303.429 | Duration of raw recording (s) |
| proc_xmax_post | 44.0 | Duration after trimming/cropping (s) |
| proc_xmax_percent | 0.145 | Proportion of usable data kept |
| epoch_length | 2.0 | Epoch length (s) |
| epoch_limits | [-1, 1] | Time window per epoch (s) |
| epoch_trials | 29 | Total epochs created |
| epoch_badtrials | 7 | Rejected epochs |
| epoch_percent | 0.759 | Percentage of epochs retained |
| proc_nComps | 121 | Number of ICA components estimated |
| proc_removeComps | [0,1,2,3,4,12,15,17,18,20,21,28,34,36,49,74] | Indices of ICA components removed |
| exclude_category | — | Categories of excluded components/channels |
Why It Matters
- Traceability: Every preprocessing decision (filters, bad channels, ICA components) is logged.
- Reproducibility: Logs can be used to replicate runs with identical parameters.
- Quality Control: Flags highlight potential artifacts or reference issues for review.
Next Steps
- Check the processing log after each run to review filter settings, rejected channels, and ICA removals.
- Use logs to compare across runs (especially when rerunning tasks that generate backups).
- Keep logs with your dataset when sharing for full reproducibility.