A VEP study in sleeping and awake one-month-old infants and its relation with social behavior

With the present study we aimed to analyze the relationship between infants' behavior and their visual evoked-potential (VEPs) response. Specifically, we want to verify differences regarding the VEP response in sleeping and awake infants and if an association between VEP components, in both groups, with neurobehavioral outcome could be identified. To do so, thirty-two full-term and healthy infants, approximately 1-month of age, were assessed through a VEP unpatterned flashlight stimuli paradigm, offered in two different intensities, and were assessed using a neurobehavioral scale. However, only 18 infants have both assessments, and therefore, these is the total included in both analysis. Infants displayed a mature neurobehavioral outcome, expected for their age. We observed that P2 and N3 components were present in both sleeping and awake infants. Differences between intensities were found regarding the P2 amplitude, but only in awake infants. Regression analysis showed that N3 amplitude predicted an adequate social interactive and internal regulatory behavior in infants who were awake during the stimuli presentation. Taking into account that social orientation and regulatory behaviors are fundamental keys for social-like behavior in 1-month-old infants, this study provides an important approach for assessing physiological biomarkers (VEPs) and its relation with social behavior, very early in postnatal development. Moreover, we evidence the importance of the infant's state when studying differences regarding visual threshold processing and its association with behavioral outcome.

We wouldlike to thank the families andinfants whoparticipated in this study. Also, we would like to thank Pedro Hispano Hospital, particularly to Dr. J. Lopes dos Santos, for all the kindness throughout the time that we were there for the data collection process. We thank to Maria de Góis-Eanes for all the help and knowledge entailed throughout this study. Furthermore, we thank Associac¸ ão Viver a Ciência for the Simbiontes prize in 2013. This work was supported by Fundac¸ ão Bial (grant number 42/08) and financed by Fundac¸ ão para a Ciência e Tecnologia (FCT) under a PhD grant (reference SFRH/BD/68263/2010).