Abstract
Delayed-response problem was presented with WGTA to 13 Japanese macaques in an attempt to obtain the comparable data to HARLOW's (3, 5). Thirteen subjects were split into the experienced group of four and the naive group of nine. The delay intervals selected were 0, 5, 15, 30, 60, 120, 180, 240, 360, and 600 sec. These intervals were given not randomly but successively, and the direct method was used. The results obtained were (1) that Japanese macaques performed much better than 80 percent of correct responses except in a very few cases, and their results are far better than that of the other species of monkey and (2) that both groups did not demonstrate any significant differences except for 5, 15 and 30 sec-delay intervals.
