I was one of the lab rats for this - I signed up so I could get a copy of my brain scan.
I found it quite easy to move blocks around, more complex tasks with more fine control was a bit harder but possible with even a limited amount of time. The only time I struggled was when trying to do anything with the thumb while walking on a treadmill - which should be expected when controlling a device with your toes!
I found it quite easy to move blocks around, more complex tasks with more fine control was a bit harder but possible with even a limited amount of time. The only time I struggled was when trying to do anything with the thumb while walking on a treadmill - which should be expected when controlling a device with your toes!