diff --git a/notebooks/be/BE_Processing.ipynb b/notebooks/be/BE_Processing.ipynb
index daafe4f..f96cb9b 100644
--- a/notebooks/be/BE_Processing.ipynb
+++ b/notebooks/be/BE_Processing.ipynb
@@ -414,6 +414,9 @@
     "if expt_type == 'BELineData' or len(pos_dims) != 2:\n",
     "    use_static_viz_func = True\n",
     "    step_chan = None\n",
+    "    vs_mode = None\n",
+    "    field_mode = None\n",
+
     "else:\n",
     "    if vs_mode not in ['AC modulation mode with time reversal', \n",
     "                                                      'DC modulation mode']:\n",