> One aspect also not investigated here is the impact of mask-wearing by the study staff during child visits and assessments [53]. The inability of infants to s

> One aspect also not investigated here is the impact of mask-wearing by the study staff during child visits and assessments [53]. The inability of infants to see full facial expressions may have eliminated non-verbal cues, muffled instructions, or otherwise altered the understanding of the test questions and instructions. They changed their methods in 2020, so they can’t attribute this to their methods or other indirect effects of the pandemic.