Now it's your turn!: Eye blink rate in a Jenga task modulated by interaction of task wait times, effortful control, and internalizing behaviors.

Dopamine is a versatile neurotransmitter with implications in many domains, including anxiety and effortful control. Where high levels of effortful control are often regarded as adaptive, other work suggests that high levels of effortful control may be a risk factor for anxiety. Dopamine signaling may be key in understanding these relations. Eye blink rate is a non-invasive proxy metric of midbrain dopamine activity. However, much work with eye blink rate has been constrained to screen-based tasks which lack in ecological validity. We tested whether changes in eye blink rate during a naturalistic effortful control task differ as a function of parent-reported effortful control and internalizing behaviors. Children played a Jenga-like game with an experimenter, but for each trial the experimenter took an increasingly long time to take their turn. Blinks-per-second were computed during each wait period. Multilevel modeling examined the relation between duration of wait period, effortful control, and internalizing behaviors on eye blink rate. We found a significant 3-way interaction between effortful control, internalizing behaviors, and duration of the wait period. Probing this interaction revealed that for children with low reported internalizing behaviors (-1 SD) and high reported effortful control (+1 SD), eye blink rate significantly decreased as they waited longer to take their turn. These findings index task-related changes in midbrain dopamine activity in relation to naturalistic task demands, and that these changes may vary as a function of individual differences in effortful control and internalizing behaviors. We discuss possible top-down mechanisms that may underlie these differences.

Clinical Considerations From Researcher-Created Morphological Awareness Assessments.

PURPOSE: Morphological awareness develops throughout formal schooling and is positively related to later reading abilities. However, there are limited standardized measures available for speech-language pathologists (SLPs) to use when assessing morphological awareness in clinical practice. The purpose of this tutorial is to guide clinicians in choosing between researcher-created measures of morphological awareness to use with their school-aged students. METHOD: We first summarize previous morphological awareness assessment research and outline important clinical considerations when choosing a morphological awareness assessment for students in early elementary grades and beyond. Second, we highlight item characteristics regarding morpheme type, frequency, shift transparency, and imageability for students in early elementary versus later grades. Third, we discuss the type of tasks (i.e., production, decomposition, and judgment) and administration modes (i.e., oral or written and static or dynamic) available to clinicians assessing the morphological awareness skills of school-aged students. Throughout the tutorial, we reference a hypothetical case study to illustrate how SLPs might apply these suggestions and link morphological awareness assessment to treatment recommendations. CONCLUSIONS: This tutorial highlights the importance of including morphological awareness assessments in clinical practice to support oral and written language development. We provide practical guidelines to help SLPs evaluate and choose appropriate morphological awareness assessments for their school-aged students as part of their comprehensive language evaluations and to support intervention planning. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24545470.

Sequential apoptotic and multiplexed proteomic evaluation of single cancer cells.

A potential cause of cancer relapse is pretreatment chemoresistant subpopulations. Identifying targetable features of subpopulations that are poorly primed for therapy-induced cell death may improve cancer therapy. Here, we develop and validate real-time BH3 profiling, a live and functional single-cell measurement of pretreatment apoptotic sensitivity that occurs upstream of apoptotic protease activation. On the same single cells, we perform cyclic immunofluorescence, which enables multiplexed immunofluorescence of more than 30 proteins on the same cell. Using cultured cells and rapid ex vivo cultures of colon cancer patient-derived xenograft (PDX) models, we identify Bak as a univariate correlate of apoptotic priming, find that poorly primed subpopulations can correspond to specific stages of the cell cycle, and, in some PDX models, identify increased expression of Bcl-XL, Mcl-1, or Her2 in subpopulations that are poorly primed for apoptosis. Last, we generate and validate mathematical models of single-cell priming that describe how targetable proteins contribute to apoptotic priming.

Trust in and Use of COVID-19 Information Sources Differs by Health Literacy among College Students.

People's health information-seeking behaviors differ by their health literacy levels. This study assessed the relationship between health literacy and college students' levels of trust in and use of a range of health information sources of COVID-19. We collected data from August to December 2020 among college students (n = 763) through an online survey. We used a health literacy measure containing three self-reported survey questions, developed by the CDC. We assessed the extent to which participants trusted and used any of the sixteen different sources of information about COVID-19. Respondents reported high levels of trusting and using COVID-19 information from the CDC, health care providers, the WHO, state/county/city health departments, and official government websites when compared to other sources. After controlling for demographic characteristics (i.e., gender, age, race, ethnicity, and income), those who reported having lower health literacy were significantly less likely to trust and use COVID-19 information from these health authorities when compared to participants who reported having higher health literacy. Students with lower self-reported health literacy indicated not trusting or using official health authority sources for COVID-19 information. Relying on low-quality information sources could create and reinforce people's misperceptions regarding the virus, leading to low compliance with COVID-19-related public health measures and poor health outcomes.

Esophageal Epithelium and Lamina Propria Are Unevenly Involved in Eosinophilic Esophagitis.

BACKGROUND & AIMS: The nature of the involvement of esophageal tissue in eosinophilic esophagitis (EoE) is unclear. We estimated the intrabiopsy site agreements of the EoE Histologic Scoring System (EoEHSS) scores for the grade (degree) and stage (extent) of involvement of the esophageal epithelial and lamina propria and examined if the EoE activity status influenced the intrabiopsy site agreement. METHODS: Demographic, clinical, and EoEHSS scores collected as part of the prospective Outcome Measures for Eosinophilic Gastrointestinal Diseases Across Ages study were analyzed. A weighted Cohen's kappa agreement coefficient (k) was used to calculate the pairwise agreements for proximal:distal, proximal:middle, and middle:distal esophageal biopsy sites, separately for grade and stage scores, for each of the 8 components of EoEHSS. A k > 0.75 was considered uniform involvement. Inactive EoE was defined as fewer than 15 eosinophils per high-powered field. RESULTS: EoEHSS scores from 1263 esophageal biopsy specimens were analyzed. The k for the stage of involvement of the dilated intercellular spaces across all 3 sites in inactive EoE was consistently greater than 0.75 (range, 0.87-0.99). The k for lamina propria fibrosis was greater than 0.75 across some of the biopsy sites but not across all 3. Otherwise, the k for all other features, for both grade and stage, irrespective of the disease activity status, was 0.75 or less (range, 0.00-0.74). CONCLUSIONS: Except for the extent of involvement of dilated intercellular spaces in inactive EoE, the remaining epithelial features and lamina propria are involved unevenly across biopsy sites in EoE, irrespective of the disease activity status. This study enhances our understanding of the effects of EoE on esophageal tissue pathology.

One-food versus six-food elimination diet therapy for the treatment of eosinophilic oesophagitis: a multicentre, randomised, open-label trial.

BACKGROUND: Empirical elimination diets are effective for achieving histological remission in eosinophilic oesophagitis, but randomised trials comparing diet therapies are lacking. We aimed to compare a six-food elimination diet (6FED) with a one-food elimination diet (1FED) for the treatment of adults with eosinophilic oesophagitis. METHODS: We conducted a multicentre, randomised, open-label trial across ten sites of the Consortium of Eosinophilic Gastrointestinal Disease Researchers in the USA. Adults aged 18-60 years with active, symptomatic eosinophilic oesophagitis were centrally randomly allocated (1:1; block size of four) to 1FED (animal milk) or 6FED (animal milk, wheat, egg, soy, fish and shellfish, and peanut and tree nuts) for 6 weeks. Randomisation was stratified by age, enrolling site, and gender. The primary endpoint was the proportion of patients with histological remission (peak oesophageal count <15 eosinophils per high-power field [eos/hpf]). Key secondary endpoints were the proportions with complete histological remission (peak count ≤1 eos/hpf) and partial remission (peak counts ≤10 and ≤6 eos/hpf) and changes from baseline in peak eosinophil count and scores on the Eosinophilic Esophagitis Histology Scoring System (EoEHSS), Eosinophilic Esophagitis Endoscopic Reference Score (EREFS), Eosinophilic Esophagitis Activity Index (EEsAI), and quality of life (Adult Eosinophilic Esophagitis Quality-of-Life and Patient Reported Outcome Measurement Information System Global Health questionnaires). Individuals without histological response to 1FED could proceed to 6FED, and those without histological response to 6FED could proceed to swallowed topical fluticasone propionate 880 µg twice per day (with unrestricted diet), for 6 weeks. Histological remission after switching therapy was assessed as a secondary endpoint. Efficacy and safety analyses were done in the intention-to-treat (ITT) population. This trial is registered on ClinicalTrials.gov, NCT02778867, and is completed. FINDINGS: Between May 23, 2016, and March 6, 2019, 129 patients (70 [54%] men and 59 [46%] women; mean age 37·0 years [SD 10·3]) were enrolled, randomly assigned to 1FED (n=67) or 6FED (n=62), and included in the ITT population. At 6 weeks, 25 (40%) of 62 patients in the 6FED group had histological remission compared with 23 (34%) of 67 in the 1FED group (difference 6% [95% CI -11 to 23]; p=0·58). We found no significant difference between the groups at stricter thresholds for partial remission (≤10 eos/hpf, difference 7% [-9 to 24], p=0·46; ≤6 eos/hpf, 14% [-0 to 29], p=0·069); the proportion with complete remission was significantly higher in the 6FED group than in the 1FED group (difference 13% [2 to 25]; p=0·031). Peak eosinophil counts decreased in both groups (geometric mean ratio 0·72 [0·43 to 1·20]; p=0·21). For 6FED versus 1FED, mean changes from baseline in EoEHSS (-0·23 vs -0·15; difference -0·08 [-0·21 to 0·05]; p=0·23), EREFS (-1·0 vs -0·6; difference -0·4 [-1·1 to 0·3]; p=0·28), and EEsAI (-8·2 vs -3·0; difference -5·2 [-11·2 to 0·8]; p=0·091) were not significantly different. Changes in quality-of-life scores were small and similar between the groups. No adverse event was observed in more than 5% of patients in either diet group. For patients without histological response to 1FED who proceeded to 6FED, nine (43%) of 21 reached histological remission; for patients without histological response to 6FED who proceeded to fluticasone propionate, nine (82%) of 11 reached histological remission. INTERPRETATION: Histological remission rates and improvements in histological and endoscopic features were similar after 1FED and 6FED in adults with eosinophilic oesophagitis. 6FED had efficacy in just less than half of 1FED non-responders and steroids had efficacy in most 6FED non-responders. Our findings indicate that eliminating animal milk alone is an acceptable initial dietary therapy for eosinophilic oesophagitis. FUNDING: US National Institutes of Health.

Relations Between Executive Functioning and Internalizing Symptoms Vary as a Function of Frontoparietal-amygdala Resting State Connectivity.

The prefrontal cortex and the frontoparietal network are associated with a variety of regulatory behaviors. Functional connections between these brain regions and the amygdala are implicated in risk for anxiety disorders. The prefrontal cortex and frontoparietal network are also linked to executive functioning, or behaviors that help orient action towards higher order goals. Where much research has been focused on deleterious effects of under-controlled behavior, a body of work suggests that over-controlled behavior may also pose a risk for internalizing problems. Indeed, while work suggests that high levels of attention shifting may still be protective against internalizing problems, there is evidence that high levels of inhibitory control may be a risk factor for socioemotional difficulties. In the ABCD sample, which offers large sample sizes as well as sociodemographic diversity, we test the interaction between frontoparietal network-amygdala resting state functional connectivity and executive functioning behaviors on longitudinal changes in internalizing symptoms from approximately 10 to 12 years of age. We found that higher proficiency in attention shifting indeed predicts fewer internalizing behaviors over time. In addition, higher proficiency in inhibitory control predicts fewer internalizing symptoms over time, but only for children showing resting state connectivity moderately above the sample average between the frontoparietal network and amygdala. This finding supports the idea that top-down control may not be adaptive for all children, and relations between executive functioning and anxiety risk may vary as a function of trait-level regulation.

Social Model Hospice Homes: Bridging the Gap in End-of-Life Care Delivery.

Background: People prefer to die at home, if given a choice. However, data show that less than half of hospice patients get to do so, as many lack the social resources needed for end-of-life (EOL) care to be supported at home. The Social Model Hospice Home (SMHh) is an emerging model of care and offers an option for individuals whose EOL care cannot be fully supported by their available social network. An SMHh is a community-supported home staffed with round the clock caregivers dedicated to closing this social gap in EOL care delivery. Objective: This study aimed to enhance and clarify the reasons for successful outcomes of the SMHh concept. Methods: This study used a qualitative descriptive approach. Twenty-three semistructured interviews were conducted with the participants. Located throughout North America, participants consisted of staff, volunteers, guests, family members of previous guests, board members, and administrators of SMHh programs. Results: Over the course of the study, five major themes were developed: (1) physical attributes of the home, (2) volunteer base, (3) attention to detail, (4) structure of accountability, and (5) practice of compassionate honesty. These themes reveal the beginning of an explanatory theory of why the SMHh concept can support the delivery of effective, high-quality EOL care. Conclusions: The result of this study substantiates SMHh as a viable alternative to traditional in-home or institution-based EOL care. As the SMHh movement develops, more research is needed to explore and understand how this emerging model of care can be implemented on a larger scale.

Assessing bidirectional relations between infant temperamental negative affect, maternal anxiety symptoms and infant affect-biased attention across the first 24-months of life.

Developmental theories suggest affect-biased attention, preferential attention to emotionally salient stimuli, emerges during infancy through coordinating individual differences. Here we examined bidirectional relations between infant affect-biased attention, temperamental negative affect, and maternal anxiety symptoms using a Random Intercepts Cross-Lagged Panel model (RI-CLPM). Infant-mother pairs from Central Pennsylvania and Northern New Jersey (N = 342; 52% White; 50% reported as assigned female at birth) participated when infants were 4, 8, 12, 18 and 24 months of age. Infants completed the overlap task while eye-tracking data were collected. Mothers reported their infant's negative affect and their own anxiety symptoms. In an RI-CLPM, after accounting for between-person variance (random intercepts representing the latent average of a construct), it is possible to assess within-person variance (individual deviations from the latent average of a construct). Positive relations represent stability in constructs (smaller within-person deviations). Negative relations represent fluctuation in constructs (larger within-person deviations). At the between-person level (random intercepts), mothers with greater anxiety symptoms had infants with greater affect-biased attention. However, at the within-person level (deviations), greater fluctuation in maternal anxiety symptoms at 12- and 18 months prospectively related to greater stability in attention to angry facial configurations. Additionally, greater fluctuation in maternal anxiety symptoms at 18 months prospectively related to greater stability in attention to happy facial configurations. Finally, greater fluctuation in maternal anxiety symptoms at 4- and 12 months prospectively related to greater stability in infant negative affect. These results suggest that environmental uncertainty, linked to fluctuating maternal anxiety, may shape early socioemotional development. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Sexual Function and Help-Seeking Behaviors following Childbirth: A Cross-Sectional Study.

This study examined 573 postpartum women's perceptions of changes in their sexual function and their help-seeking behaviors. Women residing in Ohio, Michigan, or Pennsylvania, USA, completed an online survey. Most women reported decreased postpartum sexual desire and/or arousal. Among women reporting decreased sexual function, most did not seek help from informal sources of support or health care professions (HCPs). Of those who did seek help from an HCP, in each domain of sexual function, only around half received helpful treatment. Women who did not seek help for their decreased sexual desire or arousal reported greater negative perceived impact of pregnancy/childbirth on their sexual function than women who did seek help.

Variability in caregiver attention bias to threat: A Goldilocks effect in infant emotional development?

Attention biases to threat are considered part of the etiology of anxiety disorders. Attention bias variability (ABV) quantifies intraindividual fluctuations in attention biases and may better capture the relation between attention biases and psychopathology risk versus mean levels of attention bias. ABV to threat has been associated with attentional control and emotion regulation, which may impact how caregivers interact with their child. In a relatively diverse sample of infants (50% White, 50.7% female), we asked how caregiver ABV to threat related to trajectories of infant negative affect across the first 2 years of life. Families were part of a multi-site longitudinal study, and data were collected from 4 to 24 months of age. Multilevel modeling examined the effect of average caregiver attention biases on changes in negative affect. We found a significant interaction between infant age and caregiver ABV to threat. Probing this interaction revealed that infants of caregivers with high ABV showed decreases in negative affect over time, while infants of caregivers with low-to-average ABV showed potentiated increases in negative affect. We discuss how both high and extreme patterns of ABV may relate to deviations in developmental trajectories.

Priority Areas for Child Diaper Access: Low-Income Neighborhoods with Limited Retail Access to the Basic Need of Diapers.

Introduction: Although a requirement for the health and hygiene of young children, millions of US families with low-incomes have unmet needs for diapers. The present study explored retail options in Durham County, NC for purchasing diapers in low-income neighborhoods in effort to increase our understanding of the overall context of diaper need. Methods: During June 2018, we visited 63 retailers selling 2460 child diaper products in 29 census tracts with a median household income ≤200% of the federal poverty guideline. Corner stores were the only retailers to sell products without original packaging, including one corner store selling loose diapers for $1.49 each. Next, we calculated bus routes to determine accessibility of the retailer with the lowest prices and greatest selection. One-way bus travel from all other census tracts to a big-box store required taking two buses combined with an average of 11 min walking for an average travel time of 43 min. We deemed census tracts as "priority areas for diaper access" when they were characterized as: (1) low income and (2) low access with no retailer selling all of the 10 most common child diaper sizes. Results: Nearly half (n=13) of the census tracts in our sample met our criteria for priority areas. We compared neighborhood characteristics of priority areas with all other county census tracts. Families living in priority areas were statistically significantly more likely to: identify as Black or African American, face challenges affording housing costs, have homes or automobiles in need of repair, experience neighborhood violence, and have less educational attainment.

A Deep Multi-Label Segmentation Network For Eosinophilic Esophagitis Whole Slide Biopsy Diagnostics.

Eosinophilic esophagitis (EoE) is an allergic inflammatory condition of the esophagus associated with elevated numbers of eosinophils. Disease diagnosis and monitoring require determining the concentration of eosinophils in esophageal biopsies, a time-consuming, tedious and somewhat subjective task currently performed by pathologists. Here, we developed a machine learning pipeline to identify, quantitate and diagnose EoE patients' at the whole slide image level. We propose a platform that combines multi-label segmentation deep network decision support system with dynamics convolution that is able to process whole biopsy slide. Our network is able to segment both intact and not-intact eosinophils with a mean intersection over union (mIoU) of 0.93. This segmentation enables the local quantification of intact eosinophils with a mean absolute error of 0.611 eosinophils. We examined a cohort of 1066 whole slide images from 400 patients derived from multiple institutions. Using this set, our model achieved a global accuracy of 94.75%, sensitivity of 94.13%, and specificity of 95.25% in reporting EoE disease activity. Our work provides state-of-the-art performances on the largest EoE cohort to date, and successfully addresses two of the main challenges in EoE diagnostics and digital pathology, the need to detect several types of small features simultaneously, and the ability to analyze whole slides efficiently. Our results pave the way for an automated diagnosis of EoE and can be utilized for other conditions with similar challenges.

Bi-directional relations between attention and social fear across the first two years of life.

This study examined longitudinal relations between attention and social fear across the first two years of life. Our sample consisted of 357 infants and their caregivers across three sites. Data was collected at 4, 8, 12, 18, and 24 months of age. At all 5 assessments, the infants participated in 2 eye-tracking tasks (Vigilance and Overlap) which measured different components of attention bias (orientation, engagement, and disengagement), and parents completed questionnaires assessing infant temperament. For the first three assessments, social fear was measured using the Infant Behavioral Questionnaire-Revised (IBQ-R; Gartstein & Rothbart, 2003) focused on interactions with strangers, and for the final two time points, we used the social fearfulness subscale on the Toddler Behavior Assessment Questionnaire (TBAQ; Goldsmith, 1996). The results of a random intercept cross-lagged panel model showed intermittent evidence of uni-directional and reciprocal relations between attention to both threatening and positive emotion facial configurations and social fear. Our findings suggest that characteristics of behaviorally inhibited temperament-in this case, social fear-begin to interact with attention biases to emotion in the very first year of life, which carries implications for the timing of future interventions designed to mitigate the early development of maladaptive patterns of attention.

Structural Brain Correlates of Childhood Inhibited Temperament: An ENIGMA-Anxiety Mega-analysis.

Temperament involves stable behavioral and emotional tendencies that differ between individuals, which can be first observed in infancy or early childhood and relate to behavior in many contexts and over many years.1 One of the most rigorously characterized temperament classifications relates to the tendency of individuals to avoid the unfamiliar and to withdraw from unfamiliar people, objects, and unexpected events. This temperament is referred to as behavioral inhibition or inhibited temperament (IT).2 IT is a moderately heritable trait1 that can be measured in multiple species.3 In humans, levels of IT can be quantified from the first year of life through direct behavioral observations or reports by caregivers or teachers. Similar approaches as well as self-report questionnaires on current and/or retrospective levels of IT1 can be used later in life.

Heterogeneity in PFC-amygdala connectivity in middle childhood, and concurrent interrelations with inhibitory control and anxiety symptoms.

The prefrontal cortex (PFC) is a key brain area in considering adaptive regulatory behaviors. This includes regulatory projections to regions of the limbic system such as the amygdala, where the nature of functional connections may confer lower risk for anxiety disorders. The PFC is also associated with behaviors like executive functioning. Inhibitory control is a behavior encompassed by executive functioning and is generally viewed favorably for adaptive socioemotional development. Yet, some research suggests that high levels of inhibitory control may actually be a risk factor for some maladaptive developmental outcomes, like anxiety disorders. In a sample of 51 children ranging from 7 to 9 years old, we examined resting state functional connectivity between regions of the PFC and the amygdala. We used Subgrouping Group Iterative Multiple Model Estimation (S-GIMME) to identify and characterize data-driven subgroups of individuals with similar networks of connectivity between these brain regions. Generated subgroups were collapsed into children characterized by the presence or absence of recovered connections between the PFC and amygdala. For subsets of children with available data (N = 38-44), we then tested whether inhibitory control, as measured by a stop signal task, moderated the relation between these subgroups and child-reported anxiety symptoms. We found an inverse relation between stop-signal reaction times and reported count of anxiety symptoms when covarying for connectivity group, suggesting that greater inhibitory control was actually related to greater anxiety symptoms, but only when accounting for patterns of PFC-amygdala connectivity. These data suggest that there is a great deal of heterogeneity in the nature of functional connections between the PFC and amygdala during this stage of development. The findings also provide support for the notion of high levels of inhibitory control as a risk factor for anxiety, but trait-level biopsychosocial factors may be important to consider in assessing the nature of risk.

Developmental patterns of affective attention across the first 2 years of life.

This study examined patterns of attention toward affective stimuli in a longitudinal sample of typically developing infants (N = 357, 147 females, 50% White, 22% Latinx, 16% African American/Black, 3% Asian, 8% mixed race, 1% not reported) using two eye-tracking tasks that measure vigilance to (rapid detection), engagement with (total looking toward), and disengagement from (latency to looking away) emotional facial configurations. Infants completed each task at 4, 8, 12, 18, and 24 months of age from 2016 to 2020. Multilevel growth models demonstrate that, over the first 2 years of life, infants became faster at detecting and spent more time engaging with angry over neutral faces. These results have implications for our understanding of the development of affect-biased attention.

A Qualitative Study Documenting Black Birthing Individuals' Perspectives on the Disproportionate Rate of Preterm Birth in the Black Community.

Background: Compared with all other racial and ethnic groups, the rate of preterm birth (PTB) is 50% higher among non-Hispanic Blacks (NHB). There are limited published data focused on the etiology of the racial disparity in PTB from the perspective of Black birthing individuals who have had a lived experience with PTB. Methods: To gain insights into the etiology of the race disparity in PTB from the NHB patient's perspective, we conducted a qualitative descriptive study with NHBs who have a history of PTB. We conducted both focus group discussions (FGDs), in-depth interviews (IDIs), and used applied thematic analysis to analyze the data. Results: Seven individuals participated in 3 FGDs and 15 individuals participated in an IDI. The majority of participants named stress as a contributor to PTB among NHBs. Participants described that stress becomes an ongoing cycle with a cumulative effect on health. Three primary sources of stress were identified: (1) individual including stress from lack of personal wellness, (2) relational stress from intimate partner and familial relationships, and (3) community-level stress from occupations and societal expectations. Conclusion: Uncovering NHB patient's perspectives on the etiology of PTB is a critical step to develop interventions that mitigate the disparity impacting the Black community. Our findings suggest that multilevel interventions targeting individual-, relational-, and community-level stress may be necessary to reduce rates of PTB among NHB individuals.

Relations between social attention, expressed positive affect and behavioral inhibition during play.

Flexible social attention, including visually attending to social interaction partners, coupled with positive affect may facilitate adaptive social functioning. However, most research assessing social attention relies on static computer-based paradigms, overlooking the dynamics of social interactions and limiting understanding of individual differences in the deployment of naturalistic attention. The current study used mobile eye-tracking to examine relations between social attention, expressed affect, and behavioral inhibition during naturalistic play in young children. Children (N = 28, Mage = 6.12, 46.4% girls, 92.9% White) participated in a 5-min free play with a novel age- and sex-matched peer while mobile eye-tracking data were collected. Interactions were coded for social attention and expressed affect and modeled second-by-second, generating 4,399 observations. Children spent more time dwelling on toys than on peers or anywhere else in the room. Further analyses demonstrated children were almost twice as likely to gaze at their peer when simultaneously self-expressing positive affect. Additionally, children were more than twice as likely and more than three times as likely to self-express positive affect when dwelling on peer or in the presence of peer-expressed positive affect, respectively. Behavioral inhibition was not significantly related to social attention. However, children higher in behavioral inhibition were less likely to self-express positive affect in the presence of peer-expressed positive affect. The current results provide a snapshot of relations between social attention, expressed affect and individual differences during play and provide guidance for future work assessing the roles of social attention and positive affect in facilitating positive social interactions. (PsycInfo Database Record (c) 2022 APA, all rights reserved).