 In half of the experiment, participants could freely use their facial mimicry whereas , in the other half, they had their facial mimicry blocked by a gel.
<fluency>  In half of the experiment, participants could freely use their facial mimicry whereas , in the other half, they had their facial mimicry blocked by a gel.
 In half of the experiment, participants could freely use their facial mimicry whereas in the other half, they had their facial mimicry blocked by a gel.