Key points are not available for this paper at this time.
Joanne L. Gusella, Darwin Muir, Edward Z. Tronick, The Effect of Manipulating Maternal Behavior during an Interaction on Three- and Six-Month-Olds' Affect and Attention, Child Development, Vol. 59, No. 4 (Aug., 1988), pp. 1111-1124
Gusella et al. (Mon,) studied this question.