مفاهیم نظری و روش شناختی از تغییرات در پاسخ مغز نوزاد در طول یک پارادایم حافظه شناخت

Previously published reports have sought to elucidate the development of visual recognition memory in the human infant by investigating the modulation of infant ERPs by a familiar and novel face (e.g., de Haan and Nelson, 1997 and de Haan and Nelson, 1999. Variability in infants’ brain responses elicited under the same mnemonic condition, however, has not been previously examined. The present report undertook two separate analyses in order to examine two kinds of variability: variability in the brain’s response to a stimulus over time as a function of stimulus repetition, and variability in the brain’s response between subjects as a function of the total number of trials completed in an ERP session. There were three major findings: (a) the mid-latency negative component (Nc) and long-latency slow wave (SW) were found to dissociate cognitive processes associated with familiarity from processes associated with stimulus repetition, (b) individual differences in the number of trials an infant completes in an ERP session were observed to be associated with differences in the amplitude and latency of the Nc, and (c) individual differences in the number of trials an infant completes appear to reflect differences in the extent to which the familiar and novel faces are encoded. The implications of these results are discussed with respect to models of habituation and preferential looking, infant ERP methodology, and developmental processes.