Studies of tracking behavior; rate and time characteristics of simple corrective movements.

"Using a simple test apparatus, Ss were required to make arm-hand corrective movements of five to 80 millimeters in extent." The results show that: "1. The maximum rate and average rate of a movement increase systematically with increasing extent of movement. The relation is approximately linear in most cases… . Reaction times are relatively independent of the distance to be moved. 2. In the situations studied, rates are highest for movements from left to right and are successively lower for forward, left, and backward movements. 3… . For movements of comparable distance in each case, rates at the pointer are slightly lower, and rates at the hand are higher at the 3:1 than at the 1:1 ratio [of control sensitivity]. In general, the operator tends to compensate for the change in sensitivity in such a way as to produce nearly the same perceived result with respect to both rate and accuracy. 4. The addition of an appreciable amount of inertia to the control knob causes the rate to be decreased for given distances of movement and the precision to be slightly improved. With additional friction… the responses are speeded up and precision is definitely lower than when minimum friction is present… ." (PsycINFO Database Record (c) 2012 APA, all rights reserved)