Key points are not available for this paper at this time.
David G. Thomas, Joseph J. Campos, David W. Shucard, Douglas S. Ramsay, Janet Shucard, Semantic Comprehension in Infancy: A Signal Detection Analysis, Child Development, Vol. 52, No. 3 (Sep., 1981), pp. 798-803
Thomas et al. (Tue,) studied this question.