The structure and development of explore-exploit decision making.

A critical component of human learning reflects the balance people must achieve between focusing on the utility of what they know versus openness to what they have yet to experience. How individuals decide whether to explore new options versus exploit known options has garnered growing interest in recent years. Yet, the component processes underlying decisions to explore and whether these processes change across development remain poorly understood. By contrasting a variety of tasks that measure exploration in slightly different ways, we found that decisions about whether to explore reflect (a) random exploration that is not explicitly goal-directed and (b) directed exploration to purposefully reduce uncertainty. While these components similarly characterized the decision-making of both youth and adults, younger participants made decisions that were less strategic, but more exploratory and flexible, than those of adults. These findings are discussed in terms of how people adapt to and learn from changing environments over time.Data has been made available in the Open Science Foundation platform (osf.io).

The representation of emotion knowledge across development.

The present study examined how children spontaneously represent facial cues associated with emotion. 106 three- to six-year-old children (48 male, 58 female; 9.4% Asian, 84.0% White, 6.6% more than one race) and 40 adults (10 male, 30 female; 10% Hispanic, 30% Asian, 2.5% Black, 57.5% White) were recruited from a Midwestern city (2019-2020), and sorted emotion cues in a spatial arrangement method that assesses emotion knowledge without reliance on emotion vocabulary. Using supervised and unsupervised analyses, the study found evidence for continuities and gradual changes in children's emotion knowledge compared to adults. Emotion knowledge develops through an incremental learning process in which children change their representations using combinations of factors-particularly valence-that are weighted differently across development.

Taking your own path: Individual differences in executive function and language processing skills in child learners.

Children as old as 5 or 6 years display selective difficulties in revising initial interpretive commitments, as indicated by both online and offline measures of sentence comprehension. It is likely, however, that individual children differ in how well they can recover from misinterpretations and in the age at which they become adult-like in these abilities. To better understand the cognitive functions that support sentence processing and revision, the current work investigated how individual differences in children's ability to interpret temporarily ambiguous sentences relate to individual differences in other linguistic and domain-general cognitive abilities. Children were tested over 2 days on a battery of executive function, working memory, and language comprehension tasks. Performance on these tasks was then used to predict online and offline measures of children's ability to revise initial misinterpretations of temporarily ambiguous sentences. We found two measures of children's cognitive flexibility to be related to their ambiguity resolution abilities. These results provide converging evidence for the hypothesis that the ability to revise initial interpretive commitments is supported by domain-general executive function abilities, which are highly variable and not fully developed in children.

Category Flexibility in Emotion Learning.

Learners flexibly update category boundaries to adjust to the range of experiences they encounter. However, little is known about whether the degree of flexibility is consistent across domains. We examined whether categorization of social input, specifically emotions, is afforded more flexibility as compared to other biological input. To address this question, children (6-12 years; 32 female, 37 male; 7 Hispanic or Latino, 62 not Hispanic or Latino; 8 Black or African American, 14 multiracial, 46 White, 1 selected "other") categorized faces morphed from calm to upset and animals morphed from a horse to a cow across task phases that differed in the distribution of stimuli presented. Learners flexibly adjusted both emotion and animal category boundaries according to distributional information, yet children showed more flexibility when updating their category boundaries for emotions. These results provide support for the idea that children-who must adjust to the vast and varied emotional signals of their social partners-respond to social signals dynamically in order to make predictions about the internal states and future behaviors of others.

Children track probabilistic distributions of facial cues across individuals.

Children face a difficult task in learning how to reason about other people's emotions. How intensely facial configurations are displayed can vary not only according to what and how much emotion people are experiencing, but also across individuals based on differences in personality, gender, and culture. To navigate these sources of variability, children may use statistical information about other's facial cues to make interpretations about perceived emotions in others. We examined this possibility by testing children's ability to adjust to differences in the intensity of facial cues across different individuals. In the present study, children (6- to 10-year-olds) categorized the information communicated by facial configurations of emotion varying continuously from "calm" to "upset," with differences in the intensity of each actor's facial movements. We found that children's threshold for categorizing a facial configuration as "upset" shifted depending on the statistical information encountered about each of the different individuals. These results suggest that children are able to track individual differences in facial behavior and use these differences to flexibly update their interpretations of facial cues associated with emotion. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Categorization of Vocal Emotion Cues Depends on Distributions of Input.

Learners use the distributional properties of stimuli to identify environmentally relevant categories in a range of perceptual domains, including words, shapes, faces, and colors. We examined whether similar processes may also operate on affective information conveyed through the voice. In Experiment 1, we tested how adults (18-22-year-olds) and children (8-10-year-olds) categorized affective states communicated by vocalizations varying continuously from "calm" to "upset." We found that the threshold for categorizing both verbal (i.e., spoken word) and nonverbal (i.e., a yell) vocalizations as "upset" depended on the statistical distribution of the stimuli participants encountered. In Experiment 2, we replicated and extended these findings in adults using vocalizations that conveyed multiple negative affect states. These results suggest perceivers' flexibly and rapidly update their interpretation of affective vocal cues based upon context. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42761-021-00038-w.

Is there evidence for sensitive periods in emotional development?

During sensitive periods an individual's development is especially receptive to information from the environment in ways that it is not at earlier and later developmental stages. Here, we describe challenges in applying the concept of sensitive periods to the domain of socio-emotional development, review what applications of this approach have accomplished, and point to promising future directions. We also argue that since emotional development consists of higher-order cognitive processes, it likely involves multiple and overlapping sensitive periods tied to different mechanisms (e.g., facial recognition, reward processing, fear conditioning). Moreover, we note a distinction between the construct of a sensitive period versus the identification of an effect of early experience-two ideas that are often confused in the literature. Progress in the study of emotion will require understanding the mechanisms involved in developmental change and models that predict children's behavior based on their prior experience.

Probabilistic learning of emotion categories.

Although the configurations of facial muscles that humans perceive vary continuously, we often represent emotions as categories. This suggests that, as in other domains of categorical perception such as speech and color perception, humans become attuned to features of emotion cues that map onto meaningful thresholds for these signals given their environments. However, little is known about the learning processes underlying the representation of these salient social signals. In Experiment 1 we test the role of statistical distributions of facial cues in the maintenance of an emotion category in both children (6-8 years old) and adults (18-22 years old). Children and adults learned the boundary between neutral and angry when provided with explicit feedback (supervised learning). However, after we exposed participants to different statistical distributions of facial cues, they rapidly shifted their category boundaries for each emotion during a testing phase. In Experiments 2 and 3, we replicated this finding and also tested the extent to which learners are able to track statistical distributions for multiple actors. Not only did participants form actor-specific categories, but the distributions of facial cues also influenced participants' trait judgments about the actors. Taken together, these data are consistent with the view that the way humans construe emotion (in this case, anger) is not only flexible, but reflects complex learning about the distributions of the myriad cues individuals experience in their social environments. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Two- and three-year-olds track a single meaning during word learning: Evidence for Propose-but-verify.

A child word-learning experiment is reported that examines 2- and 3-year-olds' ability to learn the meanings of novel words across multiple, referentially ambiguous, word occurrences. Children were told they were going on an animal safari in which they would learn the names of unfamiliar animals. Critical trial sequences began with hearing a novel word (e.g., "I see a dax! Point to the dax!") while seeing photos of two unfamiliar animals. After responding and performing on two filler trials with known animals, participants encountered the novel word again ("I see another dax! Point to the dax!") in one of two experimental conditions. In the Same condition, participants saw the animal they pointed to previously when hearing "dax" alongside another unfamiliar animal that had been seen before but not paired with "dax". In the Switch condition, participants saw the animal they had not pointed to previously alongside the unfamiliar animal. Children were well above chance on Same trials, but at chance on Switch trials. Thus, although children could remember a previously selected referent and use it to inform later referent selection (Same condition), a potential referent that was not previously selected and merely co-occurred with the target word (Switch condition) was either not remembered, or simply deemed irrelevant to word meaning. This finding suggests young children do not store multiple possible meanings from a single word occurrence, but rather restrict learning to what they deemed to be the unique referent of the novel word in the moment, testing that word-meaning hypothesis on the next occurrence.

Consequences of cathodal stimulation for behavior: when does it help and when does it hurt performance?

Cathodal Transcranial Direct Current Stimulation (C-tDCS) has been reported, across different studies, to facilitate or hinder performance, or simply to have no tangible effect on behavior. This discrepancy is most prominent when C-tDCS is used to alter a cognitive function, questioning the assumption that cathodal stimulation always compromises performance. In this study, we aimed to study the effect of two variables on performance in a simple cognitive task (letter Flanker), when C-tDCS was applied to the left prefrontal cortex (PFC): (1) the time of testing relative to stimulation (during or after), and (2) the nature of the cognitive activity during stimulation in case of post-tDCS testing. In three experiments, we had participants either perform the Flanker task during C-tDCS (Experiment 1), or after C-tDCS. When the Flanker task was administered after C-tDCS, we varied whether during stimulation subjects were engaged in activities that posed low (Experiment 2) or high (Experiment 3) demands on the PFC. Our findings show that the nature of the task during C-tDCS has a systematic influence on the outcome, while timing per se does not.