Our analyses revealed five major
findings: (1) HII and CON show similar behavioral indices of memory as indexed by VPC novelty preference across three delays, (2) PSW responses were greatest over left scalp regions, (3) over temporal electrode sites HII infants show differential patterns of Nc responses to the three faces as compared to CON, (4) at temporal electrode sites, the PSW showed largest responses to the recent familiar face condition, and (5) in examining the relation between the VPC and ERP measures, CON showed a significant positive correlation between VPC novelty preference after a 24-h delay and PSW mean amplitude. The first two findings mentioned demonstrate Romidepsin ic50 the similarities found between infants who have experienced HII and typically developing infants in the present study. With GS-1101 molecular weight regard to the VPC task, both groups exhibit a VPC novelty preference only when tested immediately after familiarization but not after a 2-min or 24-h delay. This result is similar to the findings of Morgan and Hayne (2011), who used 3D pictures of cartoon-like faces, and also showed that 1-year-olds exhibited a VPC novelty preference immediately after familiarization but not after 24-h delay. Furthermore, they
found it was not until age 2 years when their participants exhibited novelty preference after 24-h delay; their study did not evaluate a 2-min delay. In contrast to our findings, studies on younger infants using slightly different testing methods than our own found novelty preference after varying time Tyrosine-protein kinase BLK delays. One study, which similarly used pictures of female faces but differed in their familiarization methods, found that 6-month-olds exhibited a novelty preference
after both a 2-min and 24-h delay (Pascalis et al., 1998). Another study, which used pictures of black-and-white sunburst and diamond patterns, found that 4-month-olds exhibited a novelty preference after a short delay lasting approximately the length of a feeding (Geva et al., 1999). It is difficult to compare these studies, as their VPC testing methods were slightly different from one another and from our own, but based on our study and that of Morgan and Hayne (2011), 12-months-old infants appear to demonstrate visual recognition memory retention on behavioral testing of less than 2 min. A second finding that showed no group differences was greater PSW mean amplitude over the left region. For the temporal electrode sites, this meant greater PSW over the left as compared to the right region, and for the frontocentral electrode sites, greater PSW over left as compared to right and middle regions. The regionalization of PSW to the left or right hemisphere has been under debate in prior studies.