Relations between maternal sensitivity and physiological reactivity to infant crying were examined using measures of heart rate (HR) and respiratory sinus arrhythmia (RSA) in 49 mothers of second-born infants. Using the Ainsworth Sensitivity Scale, an independent assessment of maternal sensitivity was made during maternal free play and bathing of…

Using electrocardiogram data with 78 six-month-old infants, this study examined the presence or absence of brief orienting bradycardia during the onset of maternal arm-restraint and subsequent differences between infants on behavioral organization during restraint. Results showed that 45 of the infants exhibited brief episodes of bradycardia at…

This study examined both differential patterns and the stability of infants' (N = 70) distress reactivity across mother and stranger arm-restraint conditions when infants were 6 and 9 months of age. Reactivity measures included observational variables for the rise, intensity, and duration of infant distress as well as motor activities associated…

What kind of featural information do infants rely on when they are trying to recognize a previously seen object? The question of whether infants use certain features (e.g., shape or color) more than others (e.g., luminance) can only be studied legitimately if visual salience is controlled, as the magnitude of feature values--how noticeable and…

Work with infants on the "visual cliff" links avoidance of drop-offs to experience with self-produced locomotion. Adolph's (2002) research on infants' perception of slope and gap traversability suggests that learning to avoid falling down is highly specific to the postural context in which it occurs. Infants, for example, who have…

Although a large literature discusses infants' preference for infant-directed speech (IDS), few studies have examined how this preference might change over time or across listening situations. The work reported here compares infants' preference for IDS while listening in a quiet versus a noisy environment, and across 3 points in development: 4.5…

To better understand the form and recognizability of neonatal smiling, 32 newborns (14 girls; M = 25.6 hr) were videorecorded in the behavioral states of alertness, drowsiness, active sleep, and quiet sleep. Baby Facial Action Coding System coding of both lip corner raising (simple or non-Duchenne) and lip corner raising with cheek raising…

This study was aimed at sorting out conflicting results in the literature concerning 2-month-olds' sensitivity to interpersonal contingency, and investigated the potential role of infants' positive emotion in contingency detection. Infants were randomly assigned to an experimental group (EG) that was presented an uninterrupted live-replay-live…