Electrical brain stimulation used with mildly impaired stroke survivors improved the ability to pinch (1). However, the improvement was "mostly in the online stage." A major weakness of computers is that they only create closed tasks. Unlike open tasks which can change often and unexpectedly, closed tasks limit what is allowed to happen. For example, video games change as the difficulty level increases, but once a player learns what is allowed at a particular level the options never change. Here is an example of how transferring skills learned in a closed environment to the real world can be a disaster. Self-driving cars cannot drive in the rain because visibility, wind, and road friction can change from moment to moment and day to day.
Moving a joy stick side to side and pushing buttons does not give computer designers a deep understanding of what the hand must do. I have seen 20 somethings open my folded shopping bags by pawing at them like a bear. The Velcro closure comes open by accident.
I watched a video of 20 somethings try to fly a kite by getting in a car. Holding the string while driving fast made the kite slide on the road. Minimal tension on the string did not tell their hands a kite must have a tail to pull it into a vertical position so the wind has a surface to push against. Real objects teach the hand to develop many different skills.
Finally, hand use is a visual-motor skill. Yet video games give low scores to people who stop to inspect an object to help them decide what the hand must do. Here is an example of how gathering visual information before moving prevents disasters in the real world. Vision tells us to increase muscle tone before we lift a large suitcase so it will not fall on our foot and to relax before we lift an empty glass so the glass will not fly out of our hand and break. Designers who make their hands move at lighting speed in a world where mistakes have no consequences for humans have blind spots about what stroke rehab must offer. homeafterstroke.blogspot.com
1. Harmoudi, M. et al. Transcranial direct current stimulation enhances motor skill learning but not
generalization in chronic stroke. Neuroral and Neural Repair. 2018; 32 (3).