Tool 02 — Atypicality Flagger

QC your neuroimaging cohort.

Cortex's reconstructor scores how typical each subject's connectivity looks. High reconstruction error = atypical subject = probable preprocessing artifact or rare phenotype worth review.

Upload connectivity data

CSV, Excel, or .npz with per-subject connectivity rows (4,950 cols). Cortex reconstructs each subject's connectivity from its latent; reconstruction MSE is the atypicality signal. z-scores are relative to your uploaded cohort.

Accepted shapes (any of):
(N, 4950) — N subjects, pre-extracted features
(100, 100) — single subject connectivity matrix
(T, 100) — single subject ROI time series (T ≥ 30) — we compute connectivity for you
Showing demo data. Upload your own .npz to get real Cortex predictions.

Reconstruction MSE distribution

Low MSE (typical)High MSE (atypical)

All scans(40)

Scan IDRecon MSEz-scoreP(ASD)Flag
sub-010400.5397+15.32σoutlier
sub-010390.3631+9.44σoutlier
sub-010380.3229+8.1σoutlier
sub-010370.3128+7.76σoutlier
sub-010040.1663+2.88σoutlier
sub-010020.1661+2.87σoutlier
sub-010160.165+2.83σoutlier
sub-010150.1518+2.39σborderline
sub-010070.1499+2.33σborderline
sub-010060.1468+2.23σborderline
sub-010340.144+2.13σborderline
sub-010230.1394+1.98σborderline
sub-010100.1383+1.94σborderline
sub-010190.1358+1.86σborderline
sub-010270.1339+1.8σborderline
sub-010050.1336+1.79σborderline
sub-010010.1265+1.55σborderline
sub-010300.1226+1.42σclean
sub-010130.1206+1.35σclean
sub-010290.1192+1.31σclean
sub-010310.1135+1.12σclean
sub-010260.1077+0.92σclean
sub-010080.1074+0.91σclean
sub-010210.1035+0.78σclean
sub-010220.093+0.43σclean
sub-010250.0924+0.41σclean
sub-010200.0879+0.26σclean
sub-010120.0606-0.65σclean
sub-010320.06-0.67σclean
sub-010240.0525-0.92σclean
sub-010360.0517-0.94σclean
sub-010030.05-1σclean
sub-010090.0477-1.08σclean
sub-010350.046-1.13σclean
sub-010180.0391-1.36σclean
sub-010330.0378-1.41σclean
sub-010110.0347-1.51σclean
sub-010140.031-1.63σclean
sub-010280.0287-1.71σclean
sub-010170.0238-1.87σclean

Select a scan

Click any row or bar to inspect a scan. Outliers warrant review of raw BOLD, head motion, and preprocessing logs.

What does this mean?

In plain English

Cortex has seen 1,545 brain scans during training. For each of your 40 uploaded scans, it tried to recreate the scan from its learned understanding. If a scan matches what Cortex expects, it reconstructs accurately. If the scan is unusual, Cortex struggles — and that reconstruction error is your outlier signal.

Think of it like a music teacher who has heard thousands of students play a piece. When a new student plays, the teacher can tell how "typical" the performance is. A wildly unusual performance doesn't mean bad — it might be brilliant, or it might be a technical mistake. But it warrants a closer listen.

Your cohort at a glance

23 clean 10 borderline 7 outlier — that's 43% flagged for review.

18% outliers is moderate. Worth reviewing — flagged scans likely have motion artifacts, registration issues, or novel phenotypes. Spot-check 2-3 outliers first before assuming a pipeline bug.

What to do with flagged scans

For each outlier, check in order: (1) head motion logs — framewise displacement > 0.3 mm is a red flag. (2) preprocessing — did registration complete? are there masking errors? (3) scan duration — too short (<5 min) produces unreliable connectivity. (4) phenotype — if technical checks pass, the subject may have a genuinely unusual neural pattern worth separate analysis.

Important caveats

Atypical does not equal "bad" — Cortex's training data was ABIDE (mixed autism/typical). A scan from a completely different population (e.g., stroke patients, children under 6) will look atypical because Cortex has never seen that phenotype. Outlier flags are not quality judgments; they flag differences from training distribution.

How the QC signal works

Cortex's reconstructor head reconstructs the 4,950-dim connectivity features from the 256-dim embedding. Low MSE = "connectivity matches learned distribution." High MSE = "this scan doesn't fit."

Common causes of outlier MSE: (1) preprocessing errors, (2) excessive head motion, (3) novel site-specific artifacts, (4) rare phenotype worth investigating. Cortex flags, humans triage.