Memory in Early Adolescents Born Prematurely: A Functional Magnetic Resonance Imaging Investigation

Abstract

This study employed functional magnetic resonance imaging to examine the functional neuroanatomy of the hippocampus and head of the caudate nucleus during 2 different types of memory tasks in a sample of 9 early adolescent children who were born preterm (neonatal intensive care unit [NICU] sample) and a group of 9 age-matched control children who were born at term. The investigation employed delayed match to sample (DMS), delayed nonmatch to sample (DNMS), and spatial memory span tasks, as well as 2 analogous perceptuomotor tasks that placed no demands on memory. The general question examined was whether preterm children show different levels of hippocampal and caudate activation during these tasks when compared to children born at term. The findings indicated that the 2 groups did not differ in functional activation of the hippocampus during the DMS and DNMS tasks. During the encoding phase of the spatial memory span task, the DMS perceptuomotor task, and the spatial memory span perceptuomotor task, the NICU sample showed greater activation change in the right caudate nucleus, and less right caudate activation change during the test phase. During the spatial span perceptuomotor task, the preterm group showed reduced activation change in the left caudate nucleus during both the encoding and test phase. Also, during the DMS perceptuomotor task, the NICU group showed increased activation change in the left caudate nucleus during encoding and decreased activation change at test. The implications of these findings for understanding the functional neuroanatomy of memory deficits are discussed, as is the potential for distinguishing the effects of neural plasticity from those of typical brain maturational processes.