This thesis investigates the nature of atypical attention in relation to autism spectrum disorders (ASD) symptoms, as well as the mechanisms by which it may relate to social impairment. First, does atypical non-social attention predict social impairment over time in the context of ASD, suggestive of a causal relationship? Second, if atypical attention plays a role in social impairments in ASD, what is the mechanism? With regards to the first question, longitudinal data with children at familial risk for ASD demonstrated a unidirectional relationship between non-social attention and social functioning at the cognitive level: 2-year-old non-social attention predicted 3- year-old face recognition, but there was no relationship between 2-year-old face popout and 3-year-old visual search. Additionally, we examined the relationships between ASD and ADHD symptoms over three years in children at high risk for both—children with fragile X syndrome. This allowed for investigating atypical non-social attention and social impairment at the symptoms level, again revealing a unidirectional relationship with ADHD symptoms predicting ASD symptoms over time but not the reverse. These findings suggest that atypical non-social attention may contribute to social impairment. With regards to the second question, a novel eye-tracking and visual search paradigm revealed how task irrelevant social stimuli in natural scenes can lead to poorer subsequent explicit spatial contextual memory and altered memory-guided attention orienting - effects that were moderated by autistic traits and social anxiety within a neurotypical population. Further, this research found cross-sectional development, comparing 6-10-year-old children to young adults, and investigated the neural markers of social stimuli's effect on memory. These studies suggest a possible mechanism whereby a reduced social attention bias could lead autistic individuals to learn and remember less about people and the social world and result in social impairment.

In 2004, Christakis and colleagues published findings that he and others used to argue for a link between early childhood television exposure and later attention problems, a claim that continues to be frequently promoted by the popular media. Using the same National Longitudinal Survey of Youth 1979 data set (N = 2,108), we conducted two multiverse analyses to examine whether the finding reported by Christakis and colleagues was robust to different analytic choices. We evaluated 848 models, including logistic regression models, linear regression models, and two forms of propensity-score analysis. If the claim were true, we would expect most of the justifiable analyses to produce significant results in the predicted direction. However, only 166 models (19.6%) yielded a statistically significant relationship, and most of these employed questionable analytic choices. We concluded that these data do not provide compelling evidence of a harmful effect of TV exposure on attention.