Event‐related potential variability as a measure of information storage in infant development

Abstract

This article describes the concept of response variability in neuropsychological development and presents a theoretical rationale for the prediction of a decrease in variability in neural responding in the first months of life. Methods for measuring variability in brain electrical activity using event‐related potentials (ERPs) are then discussed, followed by a report of a longitudinal study that employed those methods. In that study, 24 infants heard either 64 clicks or 64 tones at 5, 8, 11, 14, and 17 weeks of age. ERP latency variability to tones decreased significantly across age with this change tending to be linear. Amplitude variability also showed a significant main effect for age in both the early and late windows of the waveform. These results were most apparent in the click ERPs, with the declining variability following clear linear trends. Tone ERPs appeared to follow age trends that were similar to click ERPs, but the former were actually quadratic in nature with variability increasing and then decreasing with age. These results are then discussed within the theoretical framework provided earlier in the article.