The importance of using multiple outcome measures in infant research

An examination of measures of young children's interest in natural object categories

Developmental research utilizes various different methodologies and measures to study the cognitive development of young children; however, the reliability and validity of such measures have been a critical issue in all areas of research practices. To address this problem, particularly in the area of research on infants' interests, we examined the convergent validity of previously reported measures of children's interests in natural object categories, as indexed by (1) parents' estimation of their child's interest in the categories, (2) extrinsic (overt choices in a task), (3) intrinsic (looking time toward objects), and (4) physiological (pupil dilation) responses to objects of different categories. Additionally, we also examined the discriminant validity of all the aforementioned measures against the well-established and validated measure of parents' estimations of children's vocabulary knowledge. Children completed two tasks: (a) an eye-tracking task, where they were presented with images from a range of defined categories, which collected indices of looking time and pupillary activity; (b) a sticker-choice task, where they were asked to choose between two sticker-images from two different categories belonging to the range of categories assessed in the previous task. Parents completed two questionnaires to estimate (i) their child's interests and (ii) vocabulary knowledge in the categories presented. We first analyzed the discriminant validity between the two parent measures, and found a significant positive association between them. Our successive analyses showed no strong or significant associations between any of our measures, apart from a significant positive association between children's looking time and parents' estimations of children's vocabulary knowledge. From our findings, we conclude that measures of infants' interests thus far may not have sufficient reliability to adequately capture any potential relationship between these measures, or index different components of interest in young children. We suggest next steps for further validation studies in infant research.

Differential effects of attachment security on visual fixation to facial expressions of emotion in 14-month-old infants: an eye-tracking study

Introduction

Models of attachment and information processing suggest that the attention infants allocate to social information might occur in a schema-driven processing manner according to their attachment pattern. A major source of social information for infants consists of facial expressions of emotion. We tested for differences in attention to facial expressions and emotional discrimination between infants classified as securely attached (B), insecure-avoidant (A), and insecure-resistant (C).

Methods

Sixty-one 14-month-old infants participated in the Strange Situation Procedure and an experimental task of Visual Habituation and Visual Paired-Comparison Task (VPC). In the Habituation phase, a Low-Arousal Happy face (habituation face) was presented followed by a VPC task of 6 trials composed of two contrasting emotional faces always involving the same actress: the one used in habituation (trial old face) and a new one (trial new face) portraying changes in valence (Low-Arousal Angry face), arousal (High-Arousal Happy face), or valence + arousal (High-Arousal Angry face). Measures of fixation time (FT) and number of fixations (FC) were obtained for the habituation face, the trial old face, the trial new face, and the difference between the trial old face and the trial new face using an eye-tracking system.

Results

We found a higher FT and FC for the trial new face when compared with the trial old face, regardless of the emotional condition (valence, arousal, valence + arousal contrasts), suggesting that 14-month-old infants were able to discriminate different emotional faces. However, this effect differed according to attachment pattern: resistant-attached infants (C) had significantly higher FT and FC for the new face than patterns B and A, indicating they may remain hypervigilant toward emotional change. On the contrary, avoidant infants (A) revealed significantly longer looking times to the trial old face, suggesting overall avoidance of novel expressions and thus less sensitivity to emotional change.

Discussion

Overall, these findings corroborate that attachment is associated with infants' social information processing.

Processing Speed Deficit and Its Relationship with Math Fluency in Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVES

(1) To determine the processing speed (PS) deficit in children with ADHD; and (2) To investigate if PS deficit was the primary cause of daily dysfunction in ADHD by testing the direct and indirect effects via working memory (WM) of PS on math fluency (MF).

METHOD

Seventy-eight children (52 children with ADHD and 26 controls) were tested on their motor, perceptual, cognitive, and verbal PS, WM, and MF.

RESULTS

Children with ADHD performed worse than controls on all PS, suggesting a general PS deficit. Moreover, cognitive PS was a significant predictor for MF. Mediation analysis showed that cognitive PS had direct and indirect effects via WM on MF, suggesting PS deficit might be the primary cause of MF difficulties in ADHD.

CONCLUSION

Findings of this study suggested a general PS deficit in ADHD. Due to the importance of PS in MF, interventions for MF underachievers should include assessment and training of PS.

Pitfall or pratfall? Behavioral differences in infant learning from falling

Researchers routinely infer learning and other unobservable psychological functions based on observable behavior. But what behavioral changes constitute evidence of learning? The standard approach is to infer learning based on a single behavior across individuals, including assumptions about the direction and magnitude of change (e.g., everyone should avoid falling repeatedly on a treacherous obstacle). Here we illustrate the benefits of an alternative "multiexpression, relativist, agnostic, individualized" approach. We assessed infant learning from falling based on multiple behaviors relative to each individual's baseline, agnostic about the direction and magnitude of behavioral change. We tested infants longitudinally (10.5-15 months of age) over the transition from crawling to walking. At each session, infants were repeatedly encouraged to crawl or walk over a fall-inducing foam pit interspersed with no-fall baseline trials on a rigid platform. Our approach revealed two learning profiles. Like adults in previous work, "pit-avoid" infants consistently avoided falling. In contrast, "pit-go" infants fell repeatedly across trials and sessions. However, individualized comparisons to baseline across multiple locomotor, exploratory, and social-emotional behaviors showed that pit-go infants also learned at every session. But they treated falling as an unimpactful "pratfall" rather than an aversive "pitfall." Pit-avoid infants displayed enhanced learning across sessions and partial transfer of learning from crawling to walking, whereas pit-go infants displayed neither. Thus, reliance on a predetermined, "one-size-fits-all" behavioral expression of a psychological function can obscure different behavioral profiles and lead to erroneous inferences. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Do face-to-face interactions support 6-month-olds' understanding of the communicative function of speech?

Infants by 6 months recognize that speech communicates information between third parties. We investigated whether 6-month-olds always expect speech to communicate or whether they also consider social features of communication, like how interlocutors engage with one another. A small sample of infants watched an actor (the Speaker) choose one of two objects to play with (the target). When the Speaker could no longer reach her target object, she turned to a new actor (the Listener) and said a nonsense word. During speech, the actors were either face-to-face, the Speaker was facing away from the Listener, or the reverse. When the actors had been face-to-face, infants looked longer when the Listener selected the non-target object compared to the target. Infants looked equally regardless of what the Listener chose when either actor had been disengaged. Area-of-interest gaze coding suggests that infants were similarly interested in the interaction across conditions, but their pattern of attention to Speaker and Listener differed when the Listener was disengaged during speech. Although these experiments should be replicated with a larger sample, the findings provide initial evidence that 6-month-olds do not expect speech alone to communicate, but also attend to the social context in which speech is produced.

The Operations Triad Model and Youth Mental Health Assessments: Catalyzing a Paradigm Shift in Measurement Validation

Researchers strategically assess youth mental health by soliciting reports from multiple informants. Typically, these informants (e.g., parents, teachers, youth themselves) vary in the social contexts where they observe youth. Decades of research reveal that the most common data conditions produced with this approach consist of discrepancies across informants' reports (i.e., informant discrepancies). Researchers should arguably treat these informant discrepancies as domain-relevant information: data relevant to understanding youth mental health domains (e.g., anxiety, depression, aggression). Yet, historically, in youth mental health research as in many other research areas, one set of paradigms has guided interpretations of informant discrepancies: Converging Operations and the Multi-Trait Multi-Method Matrix (MTMM). These paradigms (a) emphasize shared or common variance observed in multivariate data, and (b) inspire research practices that treat unique variance (i.e., informant discrepancies) as measurement confounds, namely random error and/or rater biases. Several yearsw ago, the Operations Triad Model emerged to address a conceptual problem that Converging Operations does not address: Some informant discrepancies might reflect measurement confounds, whereas others reflect domain-relevant information. However, addressing this problem requires more than a conceptual paradigm shift beyond Converging Operations. This problem necessitates a paradigm shift in measurement validation. We advance a paradigm (Classifying Observations Necessitates Theory, Epistemology, and Testing [CONTEXT]) that addresses problems with using the MTMM in youth mental health research. CONTEXT optimizes measurement validity by guiding researchers to leverage (a) informants that produce domain-relevant informant discrepancies, (b) analytic procedures that retain domain-relevant informant discrepancies, and (c) study designs that facilitate detecting domain-relevant informant discrepancies.

Face processing in the infant brain after pandemic lockdown

The role of visual experience in the development of face processing has long been debated. We present a new angle on this question through a serendipitous study that cannot easily be repeated. Infants viewed short blocks of faces during fMRI in a repetition suppression task. The same identity was presented multiple times in half of the blocks (repeat condition) and different identities were presented once each in the other half (novel condition). In adults, the fusiform face area (FFA) tends to show greater neural activity for novel versus repeat blocks in such designs, suggesting that it can distinguish same versus different face identities. As part of an ongoing study, we collected data before the COVID-19 pandemic and after an initial local lockdown was lifted. The resulting sample of 12 infants (9-24 months) divided equally into pre- and post-lockdown groups with matching ages and data quantity/quality. The groups had strikingly different FFA responses: pre-lockdown infants showed repetition suppression (novel > repeat), whereas post-lockdown infants showed the opposite (repeat > novel), often referred to as repetition enhancement. These findings provide speculative evidence that altered visual experience during the lockdown, or other correlated environmental changes, may have affected face processing in the infant brain.

The kleineWeltentdecker App - A smartphone-based developmental diary

Today, a vast number of tools exist to measure development in early childhood in a variety of domains such as cognition, language, or motor, cognition. These tools vary in different aspects. Either children are examined by a trained experimenter, or caregivers fill out questionnaires. The tools are applied in the controlled setting of a laboratory or in the children's natural environment. While these tools provide a detailed picture of the current state of children's development, they are at the same time subject to several constraints. Furthermore, the measurement of an individual child's change of different skills over time requires not only one measurement but high-density longitudinal assessments. These assessments are time-consuming, and the breadth of developmental domains assessed remains limited. In this paper, we present a novel tool to assess the development of skills in different domains, a smartphone-based developmental diary app (the kleineWeltentdecker App, henceforth referred to as the APP (The German expression "kleine Weltentdecker" can be translated as "young world explorers".)). By using the APP, caregivers can track changes in their children's skills during development. Here, we report the construction and validation of the questionnaires embedded in the APP as well as the technical details. Empirical validations with children of different age groups confirmed the robustness of the different measures implemented in the APP. In addition, we report preliminary findings, for example, on children's communicative development by using existing APP data. This substantiates the validity of the assessment. With the APP, we put a portable tool for the longitudinal documentation of individual children's development in every caregiver's pocket, worldwide.

Show your work: Tools for open developmental science

Since grade school, students of many subjects have learned to "show their work" in order to receive full credit for assignments. Many of the reasons for students to show their work extend to the conduct of scientific research. And yet multiple barriers make it challenging to share and show the products of scientific work beyond published findings. This chapter discusses some of these barriers and how web-based data repositories help overcome them. The focus is on Databrary.org, a data library specialized for storing and sharing video data with a restricted community of institutionally approved investigators. Databrary was designed by and for developmental researchers, and so its features and policies reflect many of the specific challenges faced by this community, especially those associated with sharing video and related identifiable data. The chapter argues that developmental science poses some of the most interesting, challenging, and important questions in all of science, and that by openly sharing much more of the products and processes of our work, developmental scientists can accelerate discovery while making our scholarship much more robust and reproducible.

The social learning of threat and safety in the family: Parent-to-child transmission of social fears via verbal information

Parental verbal threat (vs. safety) information regarding the social world may impact a child's fear responses, evident in subjective, behavioral, cognitive, and physiological indices of fear. In this study, primary caregivers provided standardized verbal threat or safety information to their child (N = 68, M = 5.27 years; 34 girls) regarding two strangers in the lab. Following this manipulation, children reported fear beliefs for each stranger. Physiological and behavioral reactions were recorded as children engaged with the two strangers (who were blind to their characterization) in a social interaction task. Child attention to the strangers was measured in a visual search task. Parents also reported their own, and their child's, social anxiety symptoms. Children reported more fear for the stranger paired with threat information, but no significant differences were found in observed child fear, attention, or heart rate. Higher social anxiety symptoms on the side of the parents and the children exacerbated the effect of parental verbal threat on observed fear. Our findings reveal a causal influence of parental verbal threat information only for child-reported fear and highlight the need to further refine the conditions under which acquired fear beliefs persist and generalize to behavior/physiology or get overruled by nonaversive real-life encounters.

Mother's engagement with infant linked to infant's responding to threat

The early development of threat perception in infancy might be dependent on caregiver context, but this link has not yet been studied in human infants. This study examined the emergence of the young infant's response to threat in the context of variations in caregiving behavior. Eighty infant-caregiver dyads (39 female infants, all of western European descent) visited the laboratory when the infant was 5 months old. Each dyad completed a free-play task, from which we coded for the mother's level of engagement: the amount of talking, close proximity, positive affect, and attention directed toward the infant. When the infant was 7 months old, they came back to the laboratory and we used functional near infrared spectroscopy and eye tracking to measure infants' neural and attentional responses to threatening angry faces. In response to threat, infants of more-engaged mothers showed increased brain responses in the left dorsolateral prefrontal cortex-a brain region associated with emotion regulation and cognitive control among adults-and reduced attentional avoidance. These results point to a role for caregiver behavioral context in the early development of brain systems involved in human threat responding.

Violations of expectation trigger infants to search for explanations

Infants look longer and explore more following violations-of-expectation, but the reasons for these surprise-induced behaviors are unclear. One possibility is that expectancy violations heighten arousal generally, thereby increasing infants' post-surprise activity. Another possibility is that infants' exploration reflects the search for an explanation for the surprising event. We tested these alternatives in three experiments. First in Experiment 1 we confirmed that seeing an object violate expectations (by passing through a solid wall) increased infants' exploration of the surprising object, relative to when no expectancy violation was seen. Then in Experiment 2 we measured infants' exploration after they had seen the same violation event, but then an explanation for the event was provided (the wall was revealed to have a large hole in it). We found that providing this explanation abolished infants' surprise-induced exploration. In Experiment 3 we replicated this effect. Furthermore, we found that the longer infants looked at the explanation, the greater their reversal in exploratory preference (i.e., the more they ignored the surprising object). These findings demonstrate that preverbal infants both seek and recognize explanations for surprising events.

Home-based early stimulation program targeting visual and motor functions for preterm infants with delayed tracking: Feasibility of a Randomized Clinical Trial

AIMS

To verify the feasibility of a home-based early stimulation program targeting visual and motor functions in preterm infants with delayed visual tracking.

METHOD

We applied a randomized controlled trial. We included thirty low-risk preterm infants, from both genders, with delayed visual tracking, gestational between 28-37 weeks, and age at entrance between 1-2 months of corrected age, and absence of visual impairments. Infants were divided into two groups as follows: a) standard care group (SC) that received general orientation about sensory and motor development (16 infants); b) experimental group, that received a four-week home-based early stimulation program targeting visual and motor functions (ESPVM) applied by the caregivers (14 infants). The feasibility outcomes were retention and loss rates, adherence, adverse events, and stress signals. We obtained preliminary data by comparing visual tracking, motor development, and sensory behavior between groups at the end of the intervention.

RESULTS

Retention rate was high, 90 % of the caregivers provided ESPVM at least 22 days, and 70 % provided SC at least 17 days. No adverse events were reported. At the end of intervention, the ESPVM group presented higher frequencies of complete visual tracking for cards 7 (ESPVM = 57.3 %, SC = 6.3 %, p = 0.006) and 8 (ESPVM = 64.3 %, SC = 12.2 %, p = 0.013), and lower scores for total sensory profile (ESPVM: median = 58, range = 46-69; SC: median = 71, range = 54-90; p = 0.016). The groups were similar for motor development.

CONCLUSIONS

The protocol was feasible, and the results encourage a larger randomized controlled trial.

Symbolic play provides a fertile context for language development

In this study, we test the hypothesis that symbolic play represents a fertile context for language acquisition because its inherent ambiguity elicits communicative behaviors that positively influence development. Infant-caregiver dyads (N = 54) participated in two 20-minute play sessions six months apart (Time 1 = 18 months, Time 2 = 24 months). During each session, the dyads played with two sets of toys that elicited either symbolic or functional play. The sessions were transcribed and coded for several features of dyadic interaction and language; infants' linguistic proficiency was measured via parental report. The two contexts elicited different communicative and linguistic behaviors. Notably, the symbolic play condition resulted in significantly greater conversational turn-taking than functional play, and also resulted in the greater use of questions and mimetics in infant-directed speech (IDS). In contrast, caregivers used more imperative clauses in functional play. Correlational and regression analyses showed that frequent properties of symbolic play (i.e., turn-taking, yes-no questions, mimetics) were positively related to infants' language proficiency, whereas frequent features of functional play (i.e., imperatives in IDS) were negatively related. The results provide evidence supporting the hypothesis that symbolic play is a fertile context for language development, driven by the need to negotiate meaning.

Variable- and person-centered approaches to affect-biased attention in infancy reveal unique relations with infant negative affect and maternal anxiety

Affect-biased attention is an automatic process that prioritizes emotionally or motivationally salient stimuli. Several models of affect-biased attention and its development suggest that it comprises an individual's ability to both engage with and disengage from emotional stimuli. Researchers typically rely on singular tasks to measure affect-biased attention, which may lead to inconsistent results across studies. Here we examined affect-biased attention across three tasks in a unique sample of 193 infants, using both variable-centered (factor analysis; FA) and person-centered (latent profile analysis; LPA) approaches. Using exploratory FA, we found evidence for two factors of affect-biased attention: an Engagement factor and a Disengagement factor, where greater maternal anxiety was related to less engagement with faces. Using LPA, we found two groups of infants with different patterns of affect-biased attention: a Vigilant group and an Avoidant group. A significant interaction noted that infants higher in negative affect who also had more anxious mothers were most likely to be in the Vigilant group. Overall, these results suggest that both FA and LPA are viable approaches for studying distinct questions related to the development of affect-biased attention, and set the stage for future longitudinal work examining the role of infant negative affect and maternal anxiety in the emergence of affect-biased attention.

Study Protocol: Longitudinal Attention and Temperament Study

Background: Attention processes may play a central role in shaping trajectories of socioemotional development. Individuals who are clinically anxious or have high levels of trait anxiety sometimes show attention biases to threat. There is emerging evidence that young children also demonstrate a link between attention bias to salient stimuli and broad socioemotional profiles. However, we do not have a systematic and comprehensive assessment of how attention biases, and associated neural and behavioral correlates, emerge and change from infancy through toddlerhood. This paper describes the Longitudinal Attention and Temperament study (LAnTs), which is designed to target these open questions. Method: The current study examines core components of attention across the first 2 years of life, as well as measures of temperament, parental psychosocial functioning, and biological markers of emotion regulation and anxiety risk. The demographically diverse sample (N = 357) was recruited from the area surrounding State College, PA, Harrisburg, PA, and Newark, NJ. Infants and parents are assessed at 4, 8, 12, 18, and 24 months. Assessments include repeated measures of attention bias (via eye-tracking) in both infants and parents, and measures of temperament (reactivity, negative affect), parental traits (e.g., anxiety and depression), biological markers (electrophysiology, EEG, and respiratory sinus arrythmia, RSA), and the environment (geocoding, neighborhood characteristics, perceived stress). Outcomes include temperamental behavioral inhibition, social behavior, early symptom profiles, and cellular aging (e.g., telomere length). Discussion: This multi-method study aims to identify biomarkers and behavioral indicators of attentional and socioemotional trajectories. The current study brought together innovative measurement techniques to capture the earliest mechanisms that may be causally linked to a pervasive set of problem behaviors. The analyses the emerge from the study will address important questions of socioemotional development and help shape future research. Analyses systematically assessing attention bias patterns, as well as socioemotional profiles, will allow us to delineate the time course of any emerging interrelations. Finally, this study is the first to directly assess competing models of the role attention may play in socioemotional development in the first years of life.

Navigating through the experienced environment: Insights from mobile eye tracking

Researchers are acutely interested in how people engage in social interactions and navigate their environment. However, in striving for experimental or laboratory control, we often instead present individuals with representations of social and environmental constructs and infer how they would behave in more dynamic and contingent interactions. Mobile eye-tracking (MET) is one approach to connecting the laboratory to the experienced environment. MET superimposes gaze patterns captured through head or eye-glass mounted cameras pointed at the eyes onto a separate camera that captures the visual field. As a result, MET allows researchers to examine the world from the point of view of the individual in action. This review touches on the methods and questions that can be asked with this approach, illustrating how MET can provide new insight into social, behavioral, and cognitive processes from infancy through old age.