The use of space to represent abstract concepts is integral to how humans understand and process the world around them. This study is interested in the Western tendency to organize abstract information on a left-to-right basis. This includes the organization of temporal information (the mental timeline) as well as numerical information (the mental number line). Researchers have examined this phenomenon in conjunction with Western left-to-right writing systems and have hypothesized that the development of the mental timeline and number line is strengthened as writing and reading experiences develop. The present study seeks to examine the effects of early literacy skills on the development of the mental timeline and number line, as well as compare how children organize temporal and numerical information. Preschool-aged children (N=24, aged 3.5-4 years, data collection is ongoing) were presented with three cards that either featured events in a story (temporal activity) or different quantities (numerical activity). Participants were then asked to arrange these cards in order of first to last for the temporal activity and smallest to biggest for the numerical activity. Participants also participated in a Concepts of Print assessment to assess their early literacy skills. The number of LTR lines created was compared to Concepts of Print score. Temporal sequences were most commonly represented through left-to-right lines and numerical sequences were most commonly arranged non-linearly, with neither suggesting an association with early literacy. These findings raise further questions on the origins of the mental timeline and number line, as well as imply that literacy skills are not the sole contributor to this development. In examining how literacy skills may contribute to enhancing spatial cognitive abilities related to spatial representation prominent in STEM subjects, we can reevaluate the traditional dichotomy between the arts and STEM fields.

When recalling an event, remembering when things happened is difficult for both children and adults. Across many cultures, we get around this problem by representing time spatially. One ubiquitous way adults and older children use space to represent time is by using a mental timeline: a linear, mental model of time. However, we do not know to what extent the mental timeline might be a product of our biology versus a cultural invention. This study examines whether 6-month-old infants spontaneously map temporal order to a mental timeline. In this task, infants are first habituated to a triplet of images that are either presented sequentially from left-to-right (linearly) or non-linearly across the screen. During the testing phase, infants see the same set of triplets presented centrally in a congruent (where objects are presented in the same order as shown during habituation) and an incongruent (where objects are not presented in the same order) pattern. If infants spontaneously represent temporal order using a mental timeline, they should learn the sequence more efficiently when presented from left-to-right relative to nonlinearly and, consequently, discriminate between the congruent and incongruent sequences at test. In Experiment 1 (N=41, data collected in France), the sequences involved puppet faces. There was no effect of habituation condition on looking times at the test trials. In Experiment 2, we replicated the study using simplified stimuli. Preliminary data (N=22) suggests that again, the proposed hypothesis is not supported. Data are now being collected for an updated version of the task. These results suggest that infants do not spontaneously map time to a mental timeline, suggesting that the development of a mental timeline may be a product of cultural experiences such as exposure to written language.

Prior research has shown that parent spatial language use predicts child spatial language use, and as a result, a child’s spatial ability. In our current study, we seek to identify factors that influence differences in both parent and child spatial language use. Using a picture book called “Flashlight”, which contains no words, parents were instructed to read aloud to their children (N=75 dyads, range: 2-4 years). Parents created their own story based on the pictures. After the storybook task, the parent and child were given blocks to play with for 5 minutes. Both these tasks seek to examine what types of language are naturally produced between parents and children, such as spatial words, questions, and number words (e.g., “at”, “What animal is that?”, and “one”). The videos of these sessions were manually transcribed. Parents also completed a series of questionnaires on their beliefs about the utility of play and their child’s language, motor, and communication skills. We hypothesize that the more questions a parent poses, the more spatial language a child will produce. This study is multifaceted in that it examines total language used overall (tokens), different types of language, free play, and spatial abilities. Studying these aspects of communication and underlying factors that impact the type of language parents use can lead to a better understanding of children’s spatial development and the factors influencing it. For example, parents who believe that play offers children unique opportunities to learn spatial concepts might use more spatial language with their children during play, which could scaffold their child’s spatial development. By identifying these factors, we can develop ways to increase spatial language use between parents and children, thus facilitating spatial development.

Spatial skills are crucial for understanding and navigating the physical world around us. Previous research indicates spatial development begins in infancy, with sex differences present early on. These skills are predictors of later STEM achievement, highlighting the importance of nurturing them from a young age. Our study explores the impact of spatial language and play style on infants’ spatial development. We replicated a change detection mental rotation task for infants using an eye-tracker (N = 115, 47 girls, M age = 11.21 months). As infants preferentially look at novel stimuli, we recorded looking time as a measure of recognition of a change in stimulus. Additionally, we observed parent-infant dyads during play, and parents completed a survey on their infant's play, language, and motor skills. We hypothesized that parents would use more spatial language during spatial play than non-spatial play. We were also interested in whether play and language use varied by child sex. Infants showed no preference for the novel stimulus in the mental rotation task, suggesting it might not effectively measure mental rotation in infancy. Parent-infant dyads varied in engagement with the spatial toy, and no significant sex differences emerged from these measures. Due to the null findings in our change detection task, we will be designing and testing a new task for measuring mental rotation ability in infancy. Furthermore, we will also conduct analyses on the relationship between individual differences in spatial language and play to explore how these factors impact the development of spatial abilities. These findings provide insights to better support spatial development in early life.

To perform its function as a tumor suppressor, breast cancer 1 (BRCA1) must dimerize with BRCA1-associated RING domain protein 1 (BARD1). Due to this critical interaction, pathogenic BARD1 variants are also associated with increased breast and ovarian cancer risk. Genetic testing has identified many rare single-nucleotide variants (SNVs) that cause missense amino acid substitutions in BARD1. Currently, 93% (1,692 of 1,819) of BARD1 missense SNVs are classified as a variant of uncertain significance (VUS) in ClinVar. A VUS classification prevents clinicians from using genetic test results to guide patient care. Consequently, there is a strong need to functionally assess BARD1 SNVs to help resolve VUS. We applied a multiplex assay for variant effect called saturation genome editing (SGE) to functionally assess all possible 12,000 SNVs and 2,300 3-base deletions in BARD1. In SGE, we use CRISPR-Cas9 to edit all possible SNVs into a region of BARD1 in haploid HAP1 cells. BARD1 is essential for cell growth, therefore cells edited with loss-of-function variants become depleted from the population. We track which SNVs become depleted from the population by sequencing. We then generate functional scores for each variant by calculating the change in the abundance of a variant in the original SNV library versus its abundance in the cell population after 13 days in culture. Thus far, I have generated reagents for all 14,300 variants and 2,400 have completed the full experimental pipeline. Functional scores for the functionally critical BRCA1 interaction domain show depletion of 94% stop-gain, 48% splice-site, and 21% missense variants relative to 5% synonymous and 6% intronic variants. This ultimately demonstrates SGE’s ability to accurately identify functionally normal and loss-of-function BARD1 variants. Generating functional scores for all possible BARD1 variants will provide the functional evidence needed for reclassifying BARD1 VUS and definitive test results for providers treating patients with BARD1 variants.