Associations of maternal self-report anxiety-related symptoms with mother-infant 4-month face-to-face play were investigated in 119 pairs. Attention, affect, spatial orientation, and touch were coded from split-screen videotape on a 1-s time base. Self- and interactive contingency were assessed by time-series methods. Because anxiety symptoms signal emotional dysregulation, we expected to find atypical patterns of mother-infant interactive contingencies, and of degree of stability/lability within an individual's own rhythms of behavior (self-contingencies). Consistent with our optimum midrange model, maternal anxiety-related symptoms biased the interaction toward interactive contingencies that were both heightened (vigilant) in some modalities and lowered (withdrawn) in others; both may be efforts to adapt to stress. Infant self-contingency was lowered ("destabilized") with maternal anxiety symptoms; however, maternal self-contingency was both lowered in some modalities and heightened (overly stable) in others. Interactive contingency patterns were characterized by intermodal discrepancies, confusing forms of communication. For example, mothers vigilantly monitored infants visually, but withdrew from contingently coordinating with infants emotionally, as if mothers were "looking through" them. This picture fits descriptions of mothers with anxiety symptoms as overaroused/fearful, leading to vigilance, but dealing with their fear through emotional distancing. Infants heightened facial affect coordination (vigilance), but dampened vocal affect coordination (withdrawal), with mother's face-a pattern of conflict. The maternal and infant patterns together generated a mutual ambivalence.