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4-MONTH INFANTS OF DEPRESSED MOTHERS SHOW DIMINISHED VOCAL ACTIVATION IN RESPONSE TO MOTHER'S VOICE DURING FACE-TO-FACE PLAY.

Samuel Anderson, Beatrice Beebe & Joseph Jaffe. NY Psychiatric Institute 722 W 168 St Unit 108 New York NY 10032.

A systematic Markovian Partition analysis was applied to vocal data col- lected during 50 Mother-Infant play sessions that were recorded and digitized at 8 Hz. 20 of the mothers met the CES-D criterion for depression, 30 controls did not. This analysis confirmed our earlier pilot finding of no systematic evidence for reciprocally alternating vocal activation levels among either the depressed or control dyads, consistent with Stern‘s finding that a tendency toward simultaneous coaction rather than speaking in alternation is character- istic of protoconversation at this age.

A pure model of the Stern paradigm requires perfect coordination by the two partners in order to achieve simultaneous vocalizing and pausing by both -a vocal-regulatory feat unlikely to be achieved very often by either mother or infant when time is measured at a resolution of 125 msec.

And our analysis of the occasions when perfect simultaneity occurred yiel- ded no diagnostic significance. Rather, we found that only half of the infants of depressed mothers showed vocal priming: i.e., a more probable infant vocal onset when mother is already vocalizing than when she is silent. In contrast, 90% of the control infants showed the priming effect.