Twenty four mentally retarded children aged 9 - 13 years old (average 11.4)with IQ ranged from 38 to 67(averaged 52. 5) ,and 24 normal children aged 9-12 years old (average 10. 5)participated these experiments.

• 弱智儿童被试24 人；年龄9-13岁；平均年龄11.；4岁。 智商(IQ)38-67；平均智商52