Measuring Quantitative Cerebral Blood Flow in Healthy Children: A Systematic Review of Neuroimaging Techniques.

Cerebral blood flow (CBF) is an important hemodynamic parameter to evaluate brain health. It can be obtained quantitatively using medical imaging modalities such as magnetic resonance imaging and positron emission tomography (PET). Although CBF in adults has been widely studied and linked with cerebrovascular and neurodegenerative diseases, CBF data in healthy children are sparse due to the challenges in pediatric neuroimaging. An understanding of the factors affecting pediatric CBF and its normal range is crucial to determine the optimal CBF measuring techniques in pediatric neuroradiology. This review focuses on pediatric CBF studies using neuroimaging techniques in 32 articles including 2668 normal subjects ranging from birth to 18 years old. A systematic literature search was conducted in PubMed, Embase, and Scopus and reported following the preferred reporting items for systematic reviews and meta-analyses (PRISMA). We identified factors (such as age, gender, mood, sedation, and fitness) that have significant effects on pediatric CBF quantification. We also investigated factors influencing the CBF measurements in infants. Based on this review, we recommend best practices to improve CBF measurements in pediatric neuroimaging. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.

Hypodescent or ingroup overexclusion?: Children's and adults' racial categorization of ambiguous black/white biracial faces.

Two processes describe racially ambiguous Black/White Biracial categorization-the one-drop rule, or hypodescent, whereby racially ambiguous people are categorized as members of their socially subordinated racial group (i.e., Black/White Biracial faces categorized as Black) and the ingroup overexclusion effect, whereby racially ambiguous people are categorized as members of a salient outgroup, regardless of the group's status. Without developmental research with racially diverse samples, it is unclear when these categorization patterns emerge. Study 1 included White, Black, and racially diverse Biracial children (aged 3- to 7-years) and their parents to test how racial group membership and social context influence face categorization biases. To provide the clearest test of hypodescent and ingroup overexclusion, White participants came from majority White neighborhoods and Black participants from majority Black neighborhoods (with Biracial participants from more racially diverse neighborhoods)-two samples with prominent racial ingroups. Study 2 aimed to replicate the parent findings with a separate sample of White, Black, Black/White Biracial, and Asian adults. Results suggest the ingroup overexclusion effect is present across populations early in development and persists into adulthood. Additionally, categorization was meaningfully related to parental context, pinpointing a pathway that potentially contributes to ingroup overexclusion. RESEARCH HIGHLIGHTS: White, Black, and racially diverse Biracial children and adults tended to categorize racially ambiguous Black/White Biracial faces as racial outgroup members, even if the outgroup was White. This contradicts most work arguing Black/White Biracial racially ambiguous people are more often seen as Black. Children and parents' categorizations were related, though children's categorizations were not related to socialization above and beyond parents' categorizations. Children showed similar categorization patterns across dichotomous and continuous measures.

Children's social wariness toward a different-race stranger relates to individual differences in temperament.

When children first meet a stranger, there is great variation in how much they will approach and engage with the stranger. While individual differences in this type of behavior-called social wariness-are well-documented in temperament research, surprisingly little attention has been paid to the social groups (such as race) of the stranger and how these characteristics might influence children's social wariness. In contrast, research on children's social bias and interracial friendships rarely examines individual differences in temperament and how temperament might influence cross-group interactions. The current study bridges the gap across these different fields of research by examining whether the racial group of an unfamiliar peer or adult moderates the association between temperament and the social wariness that children display. Utilizing a longitudinal dataset that collected multiple measurements of children's temperament and behaviors (including parent-reported shyness and social wariness toward unfamiliar adults and peers) across early childhood, we found that 2- to 7-year-old children with high parent-reported shyness showed greater social wariness toward a different-race stranger compared to a same-race stranger, whereas children with low parent-reported shyness did not. These results point to the importance of considering racial group membership in temperament research and the potential role that temperament might play in children's cross-race interactions. RESEARCH HIGHLIGHTS: Previous research on temperament has not considered how the race of strangers could influence children's social wariness. We find evidence that 2- to 7-year-old children with high parent-reported shyness show greater social wariness toward a different-race stranger compared to a same-race stranger. These results point to the importance of considering racial group membership in temperament research. Our findings also suggest temperament may play a role in children's cross-race interactions.

Action experience in infancy predicts visual-motor functional connectivity during action anticipation.

Despite substantial evidence indicating a close link between action production and perception in early child development, less is known about how action experience shapes the processes of perceiving and anticipating others' actions. Here, we developed a novel approach to capture functional connectivity specific to certain brain areas to investigate how action experience changes the networks involved in action perception and anticipation. Nine- and-12-month-old infants observed familiar (grasping) and novel (tool-use) actions while their brain activity was measured using EEG. Infants' motor competence of both actions was assessed. A link between action experience and connectivity patterns was found, particularly during the anticipation period. During action anticipation, greater motor competence in grasping predicted greater functional connectivity between visual (occipital alpha) and motor (central alpha) regions relative to global levels of whole-brain EEG connectivity. Furthermore, visual and motor regions tended to be more coordinated in response to familiar versus novel actions and for older than younger participants. Critically, these effects were not found in the control networks (frontal-central; frontal-occipital; parietal-central; parietal-occipital), suggesting a unique role of visual-motor networks on the link between motor skills and action encoding. HIGHLIGHTS: Infants' motor development predicted functional connectivity patterns during action anticipation. Faster graspers, and older infants, showed a stronger ratio of visual-motor neural coherence. Overall whole-brain connectivity was modulated by age and familiarity with the actions. Measuring inter-site relative to whole-brain connectivity can capture specific brain-behavior links. Measures of phase-based connectivity over time are sensitive to anticipatory action.

Do preschoolers track and evaluate social includers and excluders?

Social exclusion is harmful and leads to negative consequences across the lifespan. Based on studies primarily with adults, psychologists have characterized a highly sensitive "ostracism detection system" that acts quickly and automatically to detect exclusion and mitigate its effects. However, research with children has not fully explored whether a system with similar characteristics is operational in early childhood, and prior work probing children's responses to exclusion has produced mixed findings. We investigated 4- to 6-year-old children's abilities to negatively evaluate those who have excluded them as well as to use these experiences for prosocial gossip. Children engaged one pair of play partners in an inclusive game and engaged another pair in an exclusive game. Nearly one third (n = 28 of 96) did not accurately recall who had excluded them. Yet those who did recall their game experiences evaluated excluders more negatively than includers, and they were less likely to recommend excluders as play partners to others. These findings indicate that not all children sensitively track their excluders' identities-but those who do so will evaluate excluders negatively. More work is needed to understand developments in how and when children recognize their own exclusion and whether the underlying processes should be viewed as homologous to adults' ostracism detection system.

Toddlers' action learning and memory from active and observed instructions.

From early in life, children learn to perform actions on the objects in their environments. Although children learn from observing others' actions, actively engaging with the material to be learned can be important for learning. This study tested whether instruction that included opportunities for children to be active supported toddlers' action learning. In a within-participants design, 46 22- to 26-month-old toddlers (average age = 23.3 months; 21 male) were introduced to target actions for which instruction was either active or observed (instruction order counterbalanced across children). During active instruction, toddlers were coached to perform a set of target actions. During observed instruction, toddlers saw a teacher perform the actions. Toddlers were then tested on their action learning and generalization. Surprisingly, action learning and generalization did not differ between instruction conditions. However, toddlers' cognitive maturity supported their learning from both types of instruction. One year later, children from the original sample were tested on their long-term memory for information learned from active and observed instructions. Of this sample, 26 children provided usable data for the follow-up memory task (average age = 36.7 months, range = 33-41; 12 male). Children demonstrated better memory for information learned from active instruction than for information learned from observed instruction (odds ratio = 5.23) 1 year after instruction. Active experience during instruction appears to be pivotal for supporting children's long-term memory.

Neural correlates of familiar and unfamiliar action in infancy.

Behavioral evidence shows that experience with an action shapes action perception. Neural mirroring has been suggested as a mechanism underlying this behavioral phenomenon. Suppression of electroencephalogram (EEG) power in the mu frequency band, an index of motor activation, typically reflects neural mirroring. However, contradictory findings exist regarding the association between mu suppression and motor familiarity in infant EEG studies. In this study, we investigated the neural underpinnings reflecting the role of familiarity in action perception. We measured neural processing of familiar (grasp) and novel (tool-use) actions in 9- and 12-month-old infants. Specifically, we measured infants' distinct motor/visual activity and explored functional connectivity associated with these processes. Mu suppression was stronger for grasping than for tool use, whereas significant mu and occipital alpha (indexing visual activity) suppression were evident for both actions. Interestingly, selective motor-visual functional connectivity was found during observation of familiar action, a pattern not observed for novel action. Thus, the neural correlates of perception of familiar actions may be best understood in terms of a functional neural network rather than isolated regional activity. Our findings provide novel insights on analytic approaches for identifying motor-specific neural activity while also considering neural networks involved in observing motorically familiar versus unfamiliar actions.

Social context shapes neural processing of others' actions in 9-month-old infants.

From infancy, neural processes for perceiving others' actions and producing one's own actions overlap (neural mirroring). Adults and children show enhanced mirroring in social interactions. Yet, whether social context affects mirroring in infancy, a time when processing others' actions is crucial for action learning, remains unclear. We examined whether turn-taking, an early form of social interaction, enhanced 9-month-olds' neural mirroring. We recorded electroencephalography while 9-month-olds were grasping (execution) and observing live grasps (observation). In this design, half of the infants observed and acted in alternation (turn-taking condition), whereas the other half observed several times in a row before acting (blocked condition). Replicating previous findings, infants showed significant 6- to 9-Hz mu suppression (indicating motor activation) during execution and observation (n = 24). In addition, a condition (turn-taking or blocked) by time (action start or end) interaction indicated that infants engaged in turn-taking (n = 9), but not in the blocked context (n = 15), showed more mirroring when observing the action start compared with the action end. Exploratory analyses further suggest that (a) there is higher visual-motor functional connectivity in turn-taking toward the action's end, (b) mirroring relates to later visual-motor connectivity, and (c) visual attention as indexed by occipital alpha is enhanced in turn-taking compared with the blocked context. Together, this suggests that the neural processing of others' actions is modulated by the social context in infancy and that turn-taking may be particularly effective in engaging infants' action perception system.

Opportunities and pitfalls of social media research in rare genetic diseases: a systematic review.

PURPOSE: Social media may be particularly valuable in research in rare genetic diseases because of the low numbers of patients and the rare disease community's robust online presence. The goal of this systematic review was to understand how social media is currently used in rare disease research and the characteristics of the participants in these studies. METHODS: We conducted a systematic review of six databases to identify studies published in English between January 2004 and November 2020, of which 120 met inclusion criteria. RESULTS: Most studies were observational (n = 114, 95.0%) and cross-sectional (n = 107, 89.2%), and more than half (n = 69, 57.5%) utilized only surveys. Only 101 rare diseases were included across all studies. Participant demographics, when reported, were predominantly female (70.1% ± 22.5%) and white (85.0% ± 11.0%) adult patients and caregivers. CONCLUSION: Despite its potential benefits in rare disease research, the use of social media is still methodologically limited and the participants reached may not be representative of the rare disease population by gender, race, age, or rare disease type. As scholars explore using social media for rare disease research, careful attention should be paid to representativeness when studying this diverse patient community.

Systematic Review and Meta-Analysis of Hardware Failure in Surgical Stabilization of Rib Fractures: Who, What, When, Where, and Why?

BACKGROUND: Surgical stabilization of rib fractures (SSRF) is increasingly used to reduce pulmonary complications and death among patients with rib fractures. However, the five Ws of hardware failure -who, what, when, where, and why- remains unclear. We aimed to synthesize available evidence on the five Ws and outline future research agenda for mitigating hardware failure. METHODS: Experimental and observational studies published between 2009 and 2020 evaluating adults undergoing SSRF for traumatic rib fractures underwent evidence synthesis. We performed random effects meta-analysis of cohort/consecutive case studies. We calculated pooled prevalence of SSRF hardware failures using Freeman-Tukey double arcsine transformation and assessed study heterogeneity using DerSimonian-Laird estimation. We performed meta-regression with rib fracture acuity (acute or chronic) and hardware type (metal plate or not metal plate) as moderators. RESULTS: Twenty-nine studies underwent qualitative synthesis and 24 studies (2404 SSRF patients) underwent quantitative synthesis. Pooled prevalence of hardware failure was 4(3-7)%. Meta-regression showed fracture acuity was a significant moderator (P = 0.002) of hardware failure but hardware type was not (P = 0.23). Approximately 60% of patients underwent hardware removal after hardware failure. Mechanical failures were the most common type of hardware failure, followed by hardware infections, pain/discomfort, and non-union. Timing of hardware failure after surgery was highly variable, but 87% of failures occurred after initial hospitalization. Mechanical failures was attributed to technical shortcomings (i.e. short plate length) or excessive force on the thoracic cavity. CONCLUSIONS: SSRF hardware failure is an uncommon complication. Not all hardware failures are consequential, but insufficient individual patient data precluded characterizing where and why hardware failures occur. Minimizing SSRF hardware failure requires concerted research agenda to expand on the paucity of existing evidence.

Neighborhood racial demographics predict infants' neural responses to people of different races.

Early in life, greater exposure to diverse people can change the tendency to prefer one's own social group. For instance, infants from racially diverse environments show less preference for their own-race (ingroup) over other-race (outgroup) faces than infants from racially homogeneous environments. Yet how social environment changes ingroup versus outgroup demarcation in infancy remains unclear. A commonly held assumption is that early emerging ingroup preference is based on an affective process: feeling more comfortable with familiar ingroup than unfamiliar outgroup members. However, other processes may also underlie ingroup preference: Infants may attend more to ingroup than outgroup members and/or mirror the actions of ingroup over outgroup individuals. By aggregating 7- to 12-month-old infants' electroencephalography (EEG) activity across three studies, we disambiguate these different processes in the EEG oscillations of preverbal infants according to social environment. White infants from more racially diverse neighborhoods exhibited greater frontal theta oscillation (an index of top-down attention) and more mu rhythm desynchronization (an index of motor system activation and potentially neural mirroring) to racial outgroup individuals than White infants from less racially diverse neighborhoods. Neighborhood racial demographics did not relate to White infants' frontal alpha asymmetry (a measure of approach-withdrawal motivation) toward racial outgroup individuals. Racial minority infants showed no effects of neighborhood racial demographics in their neural responses to racial outgroup individuals. These results indicate that neural mechanisms that may underlie social bias and prejudices are related to neighborhood racial demographics in the first year of life.

Everyday interactions support toddlers' learning of conventional actions on artifacts.

Children learn to perform actions on artifacts in their environments from infancy, but the ways caregivers support this learning during everyday interactions are relatively unexplored. This study investigated how naturalistic caregiver-child teaching interactions promoted conventional action learning in toddlers. Caregivers of 32 24- to 26-month-old children taught their children to perform novel target actions on toys. Afterward, an experimenter blind to the toys children had been taught tested children's action learning. Results indicated that children's propensities to assemble objects and vocabularies were positively associated with learning. Whereas caregivers' speech did not directly support learning, caregivers' action performance negatively related to children's learning. Importantly, children's own actions related to learning: Children who performed proportionally more actions relative to their caregivers with higher action accuracy demonstrated better learning of the taught material. Thus, children who "drove" the teaching session and were more accurate in their actions learned more. Caregivers contributed by supporting their children's actions: Caregivers who provided more specific instructions and praise had children who were more active during instruction. Importantly, analyses controlled for child-level individual differences, showing that beyond children's own skills, active experience supported by caregiver guidance related to conventional action learning. These findings highlight children as central agents in the learning process and suggest that caregivers contributed by coaching children's actions.

Effect of transitional care stroke case management interventions on caregiver outcomes: the MISTT randomized trial.

This study reports on outcomes for 169 caregivers enrolled in the Michigan Stroke Transitions Trial (MISTT), an RCT of social work case management for stroke patients returning home. A mixed-model approach examined the mean change from 7- to 90-days post-discharge with group-by-time interactions for differences between treatment groups. Caregivers reported few life changes or depressive symptoms from caregiving. There was no significant change over time or treatment effects. Negative aspects of stroke caregiving may take longer to develop. Focused caregiver assessment at discharge and a better understanding of how caregiving develops over time may improve the type and timing of support.

Neural correlates of infant action processing relate to theory of mind in early childhood.

The mechanisms that support infant action processing are thought to be involved in the development of later social cognition. While a growing body of research demonstrates longitudinal links between action processing and explicit theory of mind (TOM), it remains unclear why this link emerges in some measures of action encoding and not others. In this paper, we recruit neural measures as a unique lens into which aspects of human infant action processing (i.e., action encoding and action execution; age 7 months) are related to preschool TOM (age 3 years; n = 31). We test whether individual differences in recruiting the sensorimotor system or attention processes during action encoding predict individual differences in TOM. Results indicate that reduced occipital alpha during action encoding predicts TOM at age 3. This finding converges with behavioral work and suggests that attentional processes involved in action encoding may support TOM. We also test whether neural processing during action execution draws on the proto-substrates of effortful control (EC). Results indicate that frontal alpha oscillatory activity during action execution predicted EC at age 3-providing strong novel evidence that infant brain activity is longitudinally linked to EC. Further, we demonstrate that EC mediates the link between the frontal alpha response and TOM. This indirect effect is specific in terms of direction, neural response, and behavior. Together, these findings converge with behavioral research and demonstrate that domain general processes show strong links to early infant action processing and TOM.

Learning From Others: The Effects of Agency on Event Memory in Young Children.

Little is known about the influence of social context on children's event memory. Across four studies, we examined whether learning that could occur in the absence of a person was more robust when a person was present. Three-year-old children (N = 125) viewed sequential events that either included or excluded an acting agent. In Experiment 1, children who viewed an agent recalled more than children who did not. Experiments 2a and 2b utilized an eye tracker to demonstrate this effect was not due to differences in attention. Experiment 3 used a combined behavioral and event-related potential paradigm to show that condition effects were present in memory-related components. These converging results indicate a particular role for social knowledge in supporting memory for events.

Young children and adults associate social power with indifference to others' needs.

In hierarchical societies, what do we expect from people at the top? Early in life, children use horizontal relationships (e.g., affiliation) to predict selectivity in others' prosocial behavior. But it is unknown whether children also view asymmetries in prosocial behavior as characteristic of vertical relationships (e.g., differences in social power). In two experiments, we investigated 4- to 7-year-old children's and adults' (N = 192) intuitions about links among relative authority status, helpful action, and unhelpful inaction. In Experiment 1, participants at all ages viewed a character who chose not to help another person as holding a position of authority over them; participants also viewed this unhelpful character as being less nice than the person in need. However, no age group made consistent inferences about the relative authority of a helper and a helpee. In Experiment 2, children had mixed intuitions when separately predicting whether high- and low-authority characters would be helpful in the future. However, older children and adults consistently indicated that a subordinate would be more likely than an authority to help a third party. These findings establish that children's social theories include expectations for links between power and prosociality by at least the preschool years. Whereas some judgments in this domain are stable from 4 years of age onward, others emerge gradually. Whether consistent responses occurred early or only later in development, however, all measures converged on a single intuition: People more easily associate authority with indifference to others' needs.

Unmet Needs of US Acute Stroke Survivors Enrolled in a Transitional Care Intervention Trial.

BACKGROUND: Needs of patients that go unmet after a stroke can compromise the speed and extent of recovery. While unmet needs in long-term survivors has been studied, less is known about the unmet needs of acute stroke survivors. We examine unmet needs in the immediate postdischarge period among 160 participants in the (blinded for review) a transitional care intervention conducted in (blinded for review [1 US state]) during 2016 and 2017. METHODS: Bivariate and multivariate analyses using Poisson models were used to examine the relationship between total number of unmet needs and demographics, stroke type and severity, stroke effects, and stroke risk factors. RESULTS: The mean number of unmet needs was 4.55; number of unmet needs ranged from 2 to9; all participants had some unmet need. The most common unmet needs were stroke education (73.8%), financial (33.8%), and health-related (29.4%). In the final multivariate model income and education were inversely associated with number of unmet needs. As total number of stroke effects increased, so did number of unmet needs. Demographic variables (age, gender, and race), stroke risk factors, stroke type, and stroke severity were not statistically significantly associated with the number of unmet needs. CONCLUSIONS: These results identify that in the acute post discharge period stroke survivors have many unmet needs that range from physical to psychosocial. Targeting interventions to those with the potential for greater numbers of unmet needs might be a salient clinical approach to improving stroke recovery and rehabilitation.

Professional service use among older African Americans, Black Caribbeans, and Non-Hispanic Whites for serious health and emotional problems.

This study examined racial and ethnic differences in professional service use by older African Americans, Black Caribbeans, and Non-Hispanic Whites in response to a serious personal problem. The analytic sample (N = 862) was drawn from the National Survey of American Life. Findings indicated that African Americans and Black Caribbeans were less likely to use services than Whites. Type and race of providers seen varied by respondents' race and ethnicity. Among respondents who did not seek professional help, reasons for not seeking help varied by ethnicity. Study findings are discussed in relation to practice implications.

Lung-protective ventilation for the surgical patient: international expert panel-based consensus recommendations.

Postoperative pulmonary complications (PPCs) occur frequently and are associated with substantial morbidity and mortality. Evidence suggests that reduction of PPCs can be accomplished by using lung-protective ventilation strategies intraoperatively, but a consensus on perioperative management has not been established. We sought to determine recommendations for lung protection for the surgical patient at an international consensus development conference. Seven experts produced 24 questions concerning preoperative assessment and intraoperative mechanical ventilation for patients at risk of developing PPCs. Six researchers assessed the literature using questions as a framework for their review. The modified Delphi method was utilised by a team of experts to produce recommendations and statements from study questions. An expert consensus was reached for 22 recommendations and four statements. The following are the highlights: (i) a dedicated score should be used for preoperative pulmonary risk evaluation; and (ii) an individualised mechanical ventilation may improve the mechanics of breathing and respiratory function, and prevent PPCs. The ventilator should initially be set to a tidal volume of 6-8 ml kg-1 predicted body weight and positive end-expiratory pressure (PEEP) 5 cm H2O. PEEP should be individualised thereafter. When recruitment manoeuvres are performed, the lowest effective pressure and shortest effective time or fewest number of breaths should be used.

Early emerging system for reasoning about the social nature of food.

Selecting appropriate foods is a complex and evolutionarily ancient problem, yet past studies have revealed little evidence of adaptations present in infancy that support sophisticated reasoning about perceptual properties of food. We propose that humans have an early-emerging system for reasoning about the social nature of food selection. Specifically, infants' reasoning about food choice is tied to their thinking about agents' intentions and social relationships. Whereas infants do not expect people to like the same objects, infants view food preferences as meaningfully shared across individuals. Infants' reasoning about food preferences is fundamentally social: They generalize food preferences across individuals who affiliate, or who speak a common language, but not across individuals who socially disengage or who speak different languages. Importantly, infants' reasoning about food preferences is flexibly calibrated to their own experiences: Tests of bilingual babies reveal that an infant's sociolinguistic background influences whether she will constrain her generalization of food preferences to people who speak the same language. Additionally, infants' systems for reasoning about food is differentially responsive to positive and negative information. Infants generalize information about food disgust across all people, regardless of those people's social identities. Thus, whereas food preferences are seen as embedded within social groups, disgust is interpreted as socially universal, which could help infants avoid potentially dangerous foods. These studies reveal an early-emerging system for thinking about food that incorporates social reasoning about agents and their relationships, and allows infants to make abstract, flexible, adaptive inferences to interpret others' food choices.