| Description |
Mounting evidence suggests that the slope of the electrophysiological power spectrum ("spectral slope") may reveal how synchronized neuronal activity facilitates, or thwarts, dynamic neural communication essential to efficient information processing. We sought to establish the validity of the spectral slope as a measure of dynamic neural communication in infancy. A sample of mother-infant dyads drawn from an ongoing longitudinal project were invited to participate in a supplementary study that examined the electroencephalogram (EEG) when the infant was approximately 7 months old. To date, 137 infants have been eligible to participate, of whom 85 participated in the EEG procedure. Mothers provided temperament data for 100 infants. Infants watched a 60s video and completed a modified oddball task. Converging evidence supported a regression-based approach with alpha activity removed at 5-9 Hz as a valid estimator of the spectral slope in infancy. Slope estimates predicted evoked brain activity, such that a steeper spectral slope (i.e., less neural noise) was associated with a larger response to novelty and a smaller response to fearful affect. Slope estimates were, however, unrelated to parental report of infant temperament. Findings suggest that dynamic neural communication aids cognitive processing of emotional stimuli under predictable conditions but may come at a cost in an unpredictable social environment. We discuss implications for this noninvasive signature of dynamic neural communication as it relates to normative and aberrant cognitive functioning beginning in the 1st year of life. |
