Scott Adler¹ (), Maryam Rahimi¹; ¹York University

Search asymmetry occurs when an efficient search is exhibited for feature-present targets, but an inefficient search is exhibited for feature-absent targets. Both 3-month-old infants and adults have been found to display a search asymmetry when assessed with saccade latencies (Adler & Gallego, 2014) Additionally, C-section delivered infants exhibit slower attention and saccadic latencies than those born vaginally in an attentional cueing paradigm, implicating a detriment to bottom-up attention (Adler & Wong-Kee-You, 2015). This study was designed to confirm the relative effects of different birth experiences on attention with a different attentional task, namely, search asymmetry, and whether any differences persist to adulthood. Two visual circular arrays were presented: feature-present target among feature-absent distractors (R among Ps) or feature-absent target among feature-present distractors (P among Rs) with array set sizes of 1, 3, 5, 8. Results indicated that infants’ and adults’ saccadic latencies to feature-present targets were unaffected by set size and C-section infants and adults both had slower saccadic latencies when compared to vaginal groups. Interestingly, infants born via emergency C-section were faster when compared to a planned C-section but not different from vaginal infants. There were no differences, however, in saccadic latencies between emergency and planned C-section adults. For feature-absent targets, both infants and adults exhibited increasing saccadic latencies with set size. Further, both infants and adults across all types of birth experiences exhibited equivalent saccadic latencies. These findings further suggest that C-section birth influences bottom-up attention even into adulthood. The discrepancy between the relative difference between planned and emergency C-sections in infants compared to adults suggests that multiple mechanisms, birth process versus bacterial baptism, are likely responsible for differential pattern across ages. Regardless, this study demonstrates that the development of attentional mechanisms can be influenced by early birth experiences and that this birth impact persists into adulthood.

Acknowledgements: The Hallward Fund of the Toronto Foundation