NEURAL CORRELATES OF ATTENTION AND MEMORY IN THE 1ST YEAR OF LIFE

Our understanding of the neural correlates involved in the development of attention and memory has lagged behind our knowledge of the behavioral manifestation of these abilities. This is unfortunate, as a more complete account of the brain bases for these aspects of development would likely contribute to a more thorough understanding of cognitive development in general. In this article we review previous studies from our laboratory examining recognition memory in 4-, 6-, and 8-month-old infants, and then describe more recent work with 12-month-old infants. From these data we conclude that the development of recognition memory lags behind that of attention. Specifically, by 4 months infants show event-related potential (ERP) evidence of selectively attending to stimuli presented as briefly as 100 msec. Infants this same age are also able to distinguish a single novel stimulus from a single familiar stimulus. By 6 months, infants begin to distinguish between frequently and infrequently presented events, and between familiar and novel events presented infrequently. At 8 months, infants appear able to ignore how often events have been seen and attend instead to whether these events have been seen. Finally, 12-month-old infants once again appear to be drawn to event frequency, suggesting a shift in how attention and memory resources are allocated from 6 to 12 months. From these findings, we conclude that recognition memory is comprised of several subcomponents that are still not completely assembled by the end of the first year of life.