A Caretaker Acute Stress Paradigm: Effects on behavior and physiology of caretaker and infant.

While experimental stress paradigms of infants (arm restraint; the Still-Face) are powerful tools for infant research, no study has experimentally stressed mothers to observe its independent effects on infant stress regulation. Extant caretaker/maternal stress studies essentially are correlational and confounded by other conditions (e.g., depression). Here, we present a standard procedure, the Caregiver Acute Stress Paradigm (CASP), for stressing mothers during en face interactions with their infants. We hypothesized that infants of the stressed mothers would be more distressed than infants of non-stressed mothers. A total of 106 four-month-old infants and their mothers were randomly assigned to the experimental stress or non-stress manipulation. Confirming our hypothesis, infants of the stressed mothers were significantly more likely to become distressed and require terminating the procedure. While objective ratings of maternal behavior showed no difference between groups, mother in the stress condition self-rated the episode following the caretaker stress significantly lower than mothers in the non-stress group. The self-ratings in the maternal stress-group were reflected in infant cortisol. The findings indicate that CASP is an effective experimental paradigm for exploring the independent effects of an acute stress on caretakers, including effects of conditions, such as poverty or mental illness.