TIKL: Development of a Wearable Vibrotactile Feedback Suit for Improved Human Motor Learning (Lieberman & Breazeal)

Summary:

This work is motivated by the idea of motor learning being improved by feedback over all joints, which is not available from a human instructor, especially in a large class setting. Their system includes optical tracking (based on reflecting markers on their suit), tactile actuators (vibrotactile feedback -- by pulsing a series of actuators around a joint, an order for rotation is communicated), feedback software (triggers feedback when error between the learned joint angles and current angles is high enough), and hardware for output control. Their user study compared people learning an action with only video instruction to learning it with both video and tactile feedback from the suit. They found that subjects' error in performing the motions was reduced by a statistically very significant amount (numbers around 20%).

Discussion:

I like the idea of using tactile feedback to help learn actions that involve the whole body, like dancing, but I wonder if there would be a problem with not emphasizing the important joints more than the unimportant ones. It seems to me that in dance, some amount of stylistic variation is acceptable (though I haven't spoken to any professional dancers about how important it is to have every joint bent at exactly the correct angle). Or a short person engaged in ballroom dancing with a tall person would have to position at least the arms differently than a pair of dancers of the same height. It might be possible to offset this by training the system with several different experts, and it might be slightly less of an issue with a solo activity with no props.

I also think it would be very interesting to see, as they ask when discussing future work, whether human attention can take in information from more joints of the body all at once and react effectively to it.