diff --git a/dataloader.py b/dataloader.py
index 7f560a88f3d3a5427a45a7990e4524f2b9efd4c2..b3c4525c69af1c8e4400832dc73814fba00d3f6d 100644
--- a/dataloader.py
+++ b/dataloader.py
@@ -315,7 +315,9 @@ class dataloader:
             ):
                 print(" " + sigpath)
                 # load all cells
-                record = grouper.concat_signal(sigpath, cutoff=0)
+                record = grouper.concat_signal(
+                    sigpath, cutoff=0, mode="mothers"
+                )
                 # keep cells only in key_index
                 new_record = self.get_key_cells(record, key_index)
                 # interpolate to remove internal NaNs for signals from mothers