ON THE PSYCHOPHYSICS OF ARM-POSITIONING MOVEMENTS

The basis for the relationship between physical stimulus and magnitude of psychological response in angular movements of the upper limbs was investigated. Participants compared movements to a standard location with movements to comparison locations and movements of a standard dis tance with movements of comparison distances. The results add to the c ontroversy surrounding the explanations for the differences in psychol ogical response magnitude of movements to locations and movements acro ss distances. Data obtained from movements to locations and movements across distances indicated similar Weber ratios but different patterns for the just noticeable differences. The data of this and previous re search suggest that the application of a prothetic continuum to arm mo vements is inappropriate. An alternative explanation of the difference s in the perception of movements to locations and movements across dis tances is offered.