fix(RHS2007): WE_dual separate mask for each target

Previously, the targets in black were lumped together, as were the targets in white. Now, each target, in each of the two stimuli, has its own mask idx

stimupy/papers/RHS2007.py

@@ -276,7 +276,7 @@ def WE_dual(ppd=PPD, pad=True):
     # Pad and stack
     stim1 = pad_dict_to_shape(stim1, shape, pad_value=v2)
     stim2 = pad_dict_to_shape(stim2, shape, pad_value=v2)
-    stim = stack_dicts(stim1, stim2, keep_mask_indices=True)
+    stim = stack_dicts(stim1, stim2, keep_mask_indices=False)
 
     params.update(
         visual_size=np.array(stim["img"].shape) / ppd,