Here Today, Gone Tomorrow? Changes in 4-Month-Olds' Physiologic and Behavioral Responses Do Not Indicate Memory for a Social Stressor.

Although much is known about early memory development, only a few studies have explored infants' memory of social stress. While these few studies suggest that infants can remember stressful interactions, limitations seen in both methodology and statistical analyses give pause. In the current study, 4-month-olds and their mothers participated in both stressful and non-stressful interactions over 2 days.

Structural differences in adult orbital and ventromedial prefrontal cortex predicted by infant temperament at 4 months of age.

Context: The term temperament refers to a biologically based predilection for a distinctive pattern of emotions, cognitions, and behaviors first observed in infancy or early childhood. High-reactive infants are characterized at age 4 months by vigorous motor activity and crying in response to unfamiliar visual, auditory, and olfactory stimuli, whereas low-reactive infants show low motor activity and low vocal distress to the same stimuli. High-reactive infants are biased to become behaviorally inhibited in the second year of life, defined by timidity with unfamiliar people, objects, and situations.

EEG asymmetry, power, and temperament in children.

Measures of EEG spectral power, lateral asymmetry in the frontal and parietal areas, and social behavior with an examiner were analyzed on 166 children, 10 to 12 years old, who were participating in a longitudinal study of the temperamental contributions to social behavior. Loss of 8- to 13-Hz power (alpha band) on the right, compared with the left, frontal area (right frontal active) was most prevalent among children who were classified as high reactive at 4 months and were highly fearful at 14 and 21 months. Second, greater frontal power in the 14- to 30-Hz band (beta) at rest was correlated with the tendency to be right frontal active.