Repetitive Reachfail

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I don't know what else to call this, I actually discovered this was unusual a few years ago (before my diagnosis) when teaching a class on neural control of movement. I was illustrating the role of the cerebellum in attenuating error in movements, and I noted to the class...now watch while i try and pick up this item (a pen). I missed. I just completely had "targeted" the pen incorrectly. Reached for it again, and failed again. closed my fingers just short of the pen. It eventually turned into a bobbing motion where I repeatedly failed to grasp the pen, bent backward away from target, and leaned forward again. After 4 or 5 such failures, I noted that this happened to me all the time. But not anyone else. Everyone thought it was really weird.

Anyone ever experienced anything like this?

Yes, I routinely experience such issues. Some days I will find it takes at least half a dozen attempts to pick up anything dropped on the floor, that no matter how careful I am I cannot get the teaspoon clear of the sugar jar or accurately deposit its content into a mug. I keep bumping things I mean to avoid and missing things I am attempting to touch or pick up. It can be very frustrating.

the sad thing was I was trying to illustrate how the brain can overcome errors in reaching.

FAIL.

Yes, very ironic.

Still an amusing anecdote in retrospect and probably a succesful lesson in the end; I expect most of the students would have gotten the point better than if the demonstration had worked as they will probably be reminded of the incident everytime they experience their brain overcoming errors in reaching. It probably made a more memorable point than actually demonstrating such corrrection in front of them.

I've experienced it a small handful of times. My little brother, on the other hand, has this problem all the time.

I use a technique for much more complex tasks than that which I call
Successive Approximation but the best way to describe it is try to
practice doing it very slowly. Unless you have a new (recent) vision problem
you should be able to find the pen even on the first try, by watching and
correcting the position of your fingers until they are definitely ready to
grab the pen. If you do fail, then remember how far and which way you
missed it, and try again by reaching for a place that far in the opposite
direction. When you succeed , increase the speed. I'm not sure what
changed if you suddenly discovered the problem but some normal things
could have made you forget and need to relearn. People having growth
spurts may be remembering how they did it when they were shorter,
and other normal changes may have similar results.

I am not sure if I am right about this, but I believe that forensic artists
may be using what I call Successive Approximation to draw people that
witnesses describe. The image is reduced in error (becomes more accurate)
by FEEDBACK (from the witness). You want continuous feedback from
your eyes as you reach, until you grab. If you see the pen and it for
some reason (new glasses?) isn't where you see it, adjust for that,
even if you have to feel for where it really is.

I implied two feedbacks in trying to pick up the pen:
1-going slowly toward the target until it seems reachable and reached.
2-learning to compensate for a failure by offset of the target.
Offset... if you reached too low, reach higher next time
Offset... if you reached to the left, reach to the right next time

This works for me and machines. It might not work for everyone.
I used words that I think in, which I hope make sense, but may not.