 We examined behavioral features, such as the operator gaze, head movements, and hand interactionswith hotspots, and observed significant behavioral changes as a result of continuous skill improvement.
<clarity>  We examined behavioral features, such as the operator gaze, head movements, and hand interactionswith hotspots, and observed significant behavioral changes as a result of continuous skill improvement.
 Behavioral features, such as the operator gaze, head movements, and hand interactionswith hotspots, and observed significant behavioral changes as a result of continuous skill improvement.