Children as old as five to six years of age display selective difficulties revising initial interpretive commitments, as indicated by both online and offline measures of sentence comprehension (Trueswell, Sekerina, Hill & Logrip, 1999). It is likely though that individual children differ in how well they can recover from misinterpretations and at the age they become adult-like in these abilities. To better understand the cognitive functions that support sentence processing and revision, the present work investigates 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 two 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 interpretative commitments is supported by domain-general executive function (EF) abilities (Novick, Trueswell & Thompson-Schill, 2005), which are highly variable and not fully developed in children (Anderson 2002; Davidson, Amso, Anderson & Diamond, 2006).

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.

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.

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.

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