diff --git a/scripts/barrier_picker_app/app.py b/scripts/barrier_picker_app/app.py
index 708af7d..d8988b7 100644
--- a/scripts/barrier_picker_app/app.py
+++ b/scripts/barrier_picker_app/app.py
@@ -72,9 +72,60 @@ class QueueItem:
     mp4_path: str
     duration_s: float | None
     done: bool
+    metadata: dict   # experimental fields aggregated from the merged TSV
 
 
 # ─── Queue building ─────────────────────────────────────────────────────
+_META_FIELDS = (
+    "species", "training_length_hr", "consolidation_length_hr",
+    "memory", "age", "training_date_time", "testing_date_time",
+)
+
+
+def _aggregate_metadata(rows: pd.DataFrame, db_filename: str) -> dict:
+    """Pull the experimental metadata for one video from its TSV rows.
+
+    Most fields are uniform across the 6 ROIs of a video so the first-row
+    value is representative. `male` is a per-fly label, so we summarise
+    counts. `session_role` flags whether this video was the training or
+    testing session for the flies in it.
+    """
+    if rows.empty:
+        return {}
+    # Reason: the merged xlsx/TSV currently has duplicate rows per
+    # (date, machine, ROI). De-dup on those keys so the male counts and
+    # any per-ROI fields aren't doubled.
+    if {"date", "machine_name", "roi"}.issubset(rows.columns):
+        rows = rows.drop_duplicates(subset=["date", "machine_name", "roi"])
+    r0 = rows.iloc[0]
+    meta = {}
+    for f in _META_FIELDS:
+        v = r0.get(f)
+        if pd.isna(v):
+            meta[f] = None
+        else:
+            meta[f] = v if isinstance(v, str) else (
+                int(v) if isinstance(v, float) and v.is_integer() else v
+            )
+    # Per-ROI tally.
+    if "male" in rows.columns:
+        m = rows["male"].dropna()
+        meta["n_trained"] = int((m == "trained").sum())
+        meta["n_naive"] = int((m == "naive").sum())
+    # Was this the training session, the testing session, or both?
+    is_training = rows["training_db_path"].astype(str).str.endswith(db_filename).any()
+    is_testing  = rows["testing_db_path"].astype(str).str.endswith(db_filename).any()
+    if is_training and is_testing:
+        meta["session_role"] = "training+testing"
+    elif is_training:
+        meta["session_role"] = "training"
+    elif is_testing:
+        meta["session_role"] = "testing"
+    else:
+        meta["session_role"] = "?"
+    return meta
+
+
 def _build_queue() -> list[QueueItem]:
     """Build the ordered queue of pickable videos."""
     if not TSV_PATH.exists():
@@ -120,6 +171,15 @@ def _build_queue() -> list[QueueItem]:
             inv_row = inv_by_key.get(key)
             if inv_row is None or not Path(inv_row["mp4_path"]).exists():
                 continue
+            # Reason: gather all TSV rows that reference this video — there
+            # are typically 6 ROI-rows per session, sometimes also rows
+            # using it as both training AND testing.
+            db_filename = db_path.name
+            related = tsv[
+                tsv["training_db_path"].astype(str).str.endswith(db_filename)
+                | tsv["testing_db_path"].astype(str).str.endswith(db_filename)
+            ]
+            metadata = _aggregate_metadata(related, db_filename)
             items.append(QueueItem(
                 idx=len(items),
                 machine_name=row.machine_name,
@@ -128,6 +188,7 @@ def _build_queue() -> list[QueueItem]:
                 mp4_path=inv_row["mp4_path"],
                 duration_s=inv_row["duration_s"],
                 done=key in done_keys,
+                metadata=metadata,
             ))
     return items
 
@@ -155,6 +216,7 @@ async def get_queue() -> JSONResponse:
             "session_time": q.session_time,
             "duration_s": q.duration_s,
             "done": q.done,
+            "metadata": q.metadata,
         }
         for q in queue
     ])
diff --git a/scripts/barrier_picker_app/static/index.html b/scripts/barrier_picker_app/static/index.html
index a427335..9374050 100644
--- a/scripts/barrier_picker_app/static/index.html
+++ b/scripts/barrier_picker_app/static/index.html
@@ -13,6 +13,14 @@
     #status { font-family: ui-monospace, "SF Mono", monospace; font-size: 0.85rem;
               color: #9aa; }
     #info { font-family: ui-monospace, monospace; font-size: 0.85rem; color: #cce; }
+    #meta { display: flex; gap: 1.5rem; flex-wrap: wrap; margin: 0.6rem 0 0.4rem;
+            font-size: 0.85rem; color: #aab; max-width: 1400px; width: 100%;
+            justify-content: center; }
+    #meta .pair { font-family: ui-monospace, monospace; }
+    #meta .pair .k { color: #678; }
+    #meta .pair .v { color: #def; margin-left: 0.25rem; }
+    #meta .role-training { color: #cd6 !important; }
+    #meta .role-testing { color: #6cd !important; }
     main { display: flex; flex-direction: column; align-items: center; padding: 1rem; }
     video { width: 100%; max-width: 1400px; height: auto; background: #000;
             border-radius: 4px; }
@@ -52,6 +60,7 @@
   </header>
 
   <main>
+    <div id="meta"></div>
     <video id="player" controls preload="auto"></video>
     <div id="controls">
       <button class="primary" data-mode="all">All barriers open <kbd>1</kbd></button>
@@ -77,6 +86,7 @@
   <script>
     const player = document.getElementById('player');
     const info   = document.getElementById('info');
+    const meta   = document.getElementById('meta');
     const progress = document.getElementById('progress');
     const flash  = document.getElementById('flash');
 
@@ -94,6 +104,33 @@
       progress.textContent = `${done}/${queue.length} done`;
     }
 
+    function renderMeta(m) {
+      meta.innerHTML = '';
+      if (!m) return;
+      const fields = [
+        ['role',           m.session_role,
+                           m.session_role === 'training' ? 'role-training'
+                         : m.session_role === 'testing'  ? 'role-testing' : ''],
+        ['species',        m.species],
+        ['memory',         m.memory],
+        ['training (hr)',  m.training_length_hr],
+        ['consol. (hr)',   m.consolidation_length_hr],
+        ['age (d)',        m.age],
+        ['flies',          (m.n_trained || m.n_naive)
+                           ? `${m.n_trained || 0} trained · ${m.n_naive || 0} naive`
+                           : null],
+        ['training time',  m.training_date_time],
+        ['testing time',   m.testing_date_time],
+      ];
+      for (const [label, value, cls] of fields) {
+        if (value === undefined || value === null || value === '') continue;
+        const span = document.createElement('span');
+        span.className = 'pair';
+        span.innerHTML = `<span class="k">${label}:</span><span class="v ${cls||''}">${value}</span>`;
+        meta.appendChild(span);
+      }
+    }
+
     function loadCursor() {
       if (queue.length === 0) {
         info.textContent = 'queue empty';
@@ -105,6 +142,7 @@
         `[${cursor + 1}/${queue.length}] ${item.machine_name} ${item.session_date} ${item.session_time} ` +
         (item.duration_s ? `(${(item.duration_s/60).toFixed(1)} min)` : '') +
         (item.done ? ' — already done' : '');
+      renderMeta(item.metadata);
       player.src = `/api/video/${item.idx}`;
       player.load();
     }