Xie, W., & Richards, J.E. (2016).The Relation between Infant Covert Orienting, Sustained Attention and Brain Activity. Poster presented at the International Conference on Infant Studies, New Orleans, LA, May, 2016.(pdf )
The current study investigated the cortical activity involved in infant covert orienting, and how it would be affected by the stimulus onset asynchrony (SOA) duration. We measured infant ERPs and applied cortical source analysis to measure the current density amplitudes in brain ROIs that are likely involved in covert orienting 1,2. We used the spatial cueing paradigm and tested separate groups of infants in the short and long SOA conditions to increase the number of trials and presumably enhance the power for finding a significant difference between short and long SOA conditions. The current study also aimed to determine the effect of sustained attention on infant brain activity involved in covert orienting. We used ECG recording to define infant sustained attention and inattention periods3,4. The ECG recording was synchronized with EEG recording. We found the effect of cue-target validity on infant ERP responses differs with the SOA conditions. E.g., The P1 validity effect was only shown in the short SOA condition, which is consistent with behavioral and adult ERPs research2,5,6,7. Cortical source analysis showed that the (contralateral) inferior occipital and ventral temporal regions activated differently between the valid, invalid, and neutral conditions. Infant sustained attention was found to modulate infants’ brain responses in covert orienting by enhancing the P1 and N1 ERP responses and current density amplitude in their cortical sources during sustained attention. Conclusion: the neural mechanisms that underpin covert orienting already exist in 3- to 4.5-month-olds, and they could be facilitated by infant sustained attention.