Four experiments utilized G. Johansson's (see record 1974-10267-001) technique for presenting biological motion as moving points of light. In Exp I, 9 23–53 yr old congenitally deaf signers were highly accurate in matching movements of lexical signs presented in point-light displays to those normally presented. Both discrimination accuracy and the pattern of errors were similar in this matching task to that obtained in a control condition in which the same signs were always presented normally. Exp II (6 Ss) showed that these results held for discrimination of morphological operations presented in point-light displays as well. In Exp III, 11 Ss were able to accurately identify signs of a constant handshape and morphological operations acting on signs presented in point-light displays. In Exp IV (8 Ss), aspects of the motion patterns that carried most of the information for sign identifiability were evaluated. Signs in point-light displays with certain lights removed were presented. It was found that the movement of the fingertips, but not of any other pair of points, is necessary for sign identification and that, in general, the more distal the joint, the more information its movement carries.(21 ref)(PsycInfo Database Record (c) 2023 APA, all rights reserved)