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When learners are exposed to multiple languages, semantic categories have been shown to undergo a process of convergence wherein concepts that overlap across natural languages come to be represented more similarly. Recently, we replicated this convergence effect using a simulated bilingual language learning paradigm in which participants learn one language (i.e., category boundary and associated labels) before then learning a second language with a shifted category boundary. This work, however, only assessed English-speaking monolinguals. In the present study, we extend this paradigm to bilinguals—asking whether extensive experience maintaining different label mapping systems modulates degree of semantic convergence when learners face two novel (artificial) languages. We first assessed the language experience of Polish-English bilinguals then measured representational change via the simulated bilingual language learning paradigm. We report on evidence that language history moderates the extent, and direction, of representational change, and we conclude with implications for theories of bilingual representation.

The atmospheric history of molecular hydrogen (H2) from 1852 to 2003 was reconstructed from measurements of firn air collected at Megadunes, Antarctica. The reconstruction shows that H2 levels in the southern hemisphere were roughly constant near 330 parts per billion (ppb; nmol H2 mol-1 air) during the mid to late 1800s. Over the twentieth century, H2 levels rose by about 70% to 550 ppb. The reconstruction shows good agreement with the H2 atmospheric history based on firn air measurements from the South Pole. The broad trends in atmospheric H2 over the twentieth century can be explained by increased methane oxidation and anthropogenic emissions. The H2 rise shows no evidence of deceleration during the last quarter of the twentieth century despite an expected reduction in automotive emissions following more stringent regulations. During the late twentieth century, atmospheric CO levels decreased due to a reduction in automotive emissions. It is surprising that atmospheric H2 did not respond similarly as automotive exhaust is thought to be the dominant source of anthropogenic H2. The monotonic late twentieth century rise in H2 levels is consistent with late twentieth-century flask air measurements from high southern latitudes. An additional unknown source of H2 is needed to explain twentieth-century trends in atmospheric H2 and to resolve the discrepancy between bottom-up and top-down estimates of the anthropogenic source term. The firn air-based atmospheric history of H2 provides a baseline from which to assess human impact on the H2 cycle over the last 150 y and validate models that will be used to project future trends in atmospheric composition as H2 becomes a more common energy source.

In bilinguals, certain concepts across languages come to be represented similarly—a semantic convergence effect that reflects interactivity between languages. The causal factors that affect semantic convergence are not fully understood; this gap may be due to limitations of the correlative methods used in extant work, which assesses the representations of real-world bilinguals. Here, we utilize an artificial language learning paradigm—inspired by the study of category learning—to elucidate causal influences on semantic convergence. We contrast simulated simultaneous bilingual learners with simulated sequential bilingual learners before assessing the representations of both. Bilingual groups are additionally compared to simulated monolingual controls from each language. We report on the pattern of semantic convergence and conclude with implications for theories of bilingual representation.

Research on active category learning—i.e., where the learnermanipulates continuous feature dimensions of novel objects andreceives labels for their self-generated exemplars—has routinelyshown that people prefer to sample from regions of the space withhigh class uncertainty (near category boundaries). Prevailingaccounts suggest that this strategy facilitates an understanding of thesubtle distinctions between categories. However, prior work hasfocused on situations where category boundaries are rigid. Inactuality, the boundaries between natural categories are often fuzzyor unclear. Here, we ask: do learners pursue uncertainty samplingwhen labels at the boundary are themselves uncertain? To answerthis question, we introduce a fuzzy buffer around a target categorywhere conflicting labels are returned from two ‘teachers,’ then weevaluate how sampling and representation are affected. We find that,relative to the rigid boundary case, learners avoid uncertainty,opting to sample densely from highly certain regions of the targetcategory as opposed to its boundary. Subsequent generalization testsreveal that the sampling strategies encouraged by the fuzzyboundary negatively affected participants' grasp of categorystructure, even outside the fuzzy buffer zone.

In accord with structural alignment theory, same-category comparison opportunities within a classification learning task should promote relational category acquisition. However, a straightforward merging of the classification paradigm with copresentation of same-category item pairs does not yield an advantage relative to an equal number of single-item exposures. In 3 experiments, we explore the hypothesis that the traditional classification learning mode (guess-and-correct) and comparison have a previously unforeseen incompatibility. In Experiment 1, we test this hypothesis by contrasting classification with supervised observational learning (passive study of labeled examples) under 3 presentation formats: same-category pairs, mixed pairs, and single-item. We find an observational advantage with same-category pairs and produce the elusive advantage over single-item exposures. In Experiment 2, we assess the generality of the learning mode effect by testing both same- and different-category comparison. The observational advantage replicates and extends to different-category comparison--although, we do not find a significant difference between the 2 types of comparison. In Experiment 3, relative to the classification mode, we find enhanced performance in an intermediate learning mode between classification and observation in which participants are instructed to make a covert category guess (without making an actual response) before seeing the correct category label. Implications and interpretations--including our interpretation that the performance emphasis inherent in classification learning undermines the benefits that arise from comparison opportunities--are discussed.

Research has shown that 1D category representations acquired through supervision change after unsupervised exposuresthat suggest a different boundary. However, it is unclear whether this effect generalizes to categories in which multipledimensions are relevant. To address this question, we trained participants on a 2D information integration structure (adiagonal boundary) under supervision. Participants then classified unsupervised items that implied either a steeper orflatter boundary than that established by supervision creating a conflict region where items should switch membership.Participants classified a grid of the stimulus space both immediately before (pretest) and after (posttest) unsupervisedlearning to assess for differences. We found that conflict-region items were more likely to be classified as members ofthe opposite class on the posttest, relative to pretest in a manner consistent with the unsupervised learning condition.Implications of these findings for semi-supervised learning research and theories of category learning are discussed.

A plurality of the categories we hold exhibit familyresemblance (FR; i.e., many characteristic but few definingfeatures), suggesting FR may occupy a central role in humancategory formation. However, research in unsupervisedlearning has shown that when people are asked to sort anarray of novel items into categories, they ubiquitously use aunidimensional (UNI) rule – despite the availability of a FRsolution. This work suggests that, perhaps, FR similarity isnot a core tendency in category formation. Here, we questionwhether the UNI bias is a result of the sorting paradigm.Specifically, we speculate the paradigm conflates twocomponents vital for category formation: production andevaluation. Across three experiments we show that whenevaluation is separated from generation – by using a novelforced-choice task that pits different category organizationalschemes against one another – people exhibit a FR over UNIpreference. The implications of these results are discussed.

Research on semi-supervised category learning has beensparse despite its representativeness of naturalistic categorylearning and potential applications. Most of the semi-supervised literature to date has focused on establishing thephenomenon. These efforts have produced mixed results andhave explored a relatively limited set of learningcircumstances. In the current work, we contribute a novelinvestigation of semi-supervised learning by extending theparadigm to relational category learning and evaluating therole that item similarity plays in the effectiveness ofunsupervised learning opportunities. Our results show first-ever evidence of semi-supervised learning in the induction ofrelational categories and, further, that the similarity betweensupervised and unsupervised examples critically dictateswhether benefits of unsupervised exposures accrue. Weconclude with implications and future directions.

A central goal of education is to provide students with knowledge they: (a) can successfully apply within the domain of learning and (b) can transfer, as appropriate, to new and different domains. Yet, much research has shown that learners frequently fail to access and use applicable stored knowledge when the circumstances at retrieval differ from those at encoding. Recent laboratory studies have revealed that encoding instances of a concept as members of a relational category considerably attenuates such failures of access. In the present work, we evaluate the efficacy of one such technique (category construction) applied in conjunction with direct instruction in the authentic educational setting of middle-school classrooms. Across two experiments, category construction is evaluated relative to a standard classroom practice of a worksheet with comprehension questions in order to assess how well each promotes mastery and transfer of a target concept. In addition, potential supports to improve learning outcomes are assessed: practice with category construction (Experiment 1) and partial precompletion of the category construction task (Experiment 2). Overall, we find favorable evidence that category construction leads to greater sensitivity to the underlying conceptual structure of targeted concepts and delivers transfer advantages over a worksheet control. Educational Impact and Implications Statement: A key goal of education is not only to support mastery of complex content but also to enable students to access and apply what has been learned to new settings and domains. Results from multiple inclass experiments show that supporting initial learning through category construction can enhance performance relative to a control group on assessments of mastery and transfer. This work highlights a lightweight classroom activity that could be implemented broadly to enhance educational outcomes. [ABSTRACT FROM AUTHOR]

A key goal in both education and higher-order cognitionresearch is to understand how relational concepts are bestlearned. In the current work, we present a novel approach forlearning complex relational categories – a low-support,interactive discovery interface. The platform, which allowslearners to make modifications to exemplars and see thecorresponding effects on membership, holds the potential toaugment relational learning by facilitating self-directed,alignably-different comparisons that explore what the learnerdoes not yet understand. We compared interactive learning to anidentification learning task. Participants were assessed on theirability to generalize category knowledge to novel exemplarsfrom the same domain. Although identification learners wereprovided with seven times as many positive examples of thecategory during training, interactive learners demonstratedenhanced generalization accuracy and knowledge of specificmembership constraints. Moreover, the data suggest thatidentification learners tended to overgeneralize categoryknowledge to non-members – a problem that interactive learnersexhibited to a significantly lesser degree. Overall, the resultsshow interactive training to be a powerful tool forsupplementing relational category learning, with particularutility for refining category knowledge. We conclude withimplications of these findings and promising future directions.

An important objective in higher-order cognition research isto understand how relational categories are acquired andapplied. Much of the research on relational category learninghas investigated the role of within-category comparisonopportunities in category acquisition and transfer – guided bypredictions from structure mapping theory that alignmentleads to highlighting and abstraction of shared relationalstructure (Gentner, 1983). Recent research has yielded awithin-category comparison advantage under the supervisedobservational learning mode (relative to twice as many single-item trials), but not under the supervised classification mode(Patterson & Kurtz, 2015). In the present study we investigatethe role that pressure to succeed at the training task – a criticaldifference between the two learning modes – plays in theapparent ineffectiveness of learning by comparison within theclassification mode. In a 2x2 between-subjects design wecrossed two levels of performance pressure (elevated andstandard) with two presentation formats (single-item andwithin-category pairs). The main findings are: (1) asignificant interaction showing a negative impact of increasedperformance pressure for single-item learners, but not forcomparison learners; and (2) a theoretically predicted, butempirically elusive effect of comparison over single-item inthe classification mode. We conclude that: (1) performancepressure exerts a deleterious effect on relational categorylearning (in accord with findings in the attribute categoryliterature) that opportunities to compare may compensate for;and (2) pressure to perform does not appear to underlielackluster comparison + classification performance (relativeto observational learning). Further, we offer new evidence onthe role that within-category comparison plays in relationalcategory learning.

An important goal in the study of higher-order cognition is tounderstand how relational categories are acquired andapplied. Previous work has explored the potential of withincategorycomparison opportunities to promote relationalcategory learning and transfer. This follows from predictionsof structure mapping theory (Gentner, 1983, 2003) thatalignment leads to highlighting and abstraction of commonrelational structure. However, a straightforward merging oftraditional classification learning with comparison (i.e., trialspresenting two same-category items) has not been effective.We explore the hypothesis that classification and comparisonhave an unforeseen incompatibility. In a 3x2 betweensubjectsdesign we tested three presentation conditions(unconstrained item pairs, category-matched items pairs,single items) in two supervised category learning modes:classification and observation. The major finding is aninteraction driven by highly accurate categorization for theobservational learners with same-category pairs. Theintroduction of the observational mode yielded the predicted,but elusive result of an advantage for within-category pairsover twice as many single-item trials. We conclude thatwithin-category comparison can be an effective means topromote relational category learning and discuss the apparentimpediment of the guess-and-correct cycle

BACKGROUND: Proteostasis is defined by the orchestrated control of anabolic and catabolic protein pathways. Disruption of proteostasis results in cell stress and adaptation to proteostasis imbalance is mediated by adaptive pathways such as the Heat Shock Response (including heat-shock proteins) or the unfolded protein response (UPR). The BCR-ABL1 kinase (Philadelphia chromosome) is the hallmark of chronic myeloid leukemia (CML) and defines a historically poor subset in acute lymphoblastic leukemia (Ph(+) ALL). We previously demonstrated the importance of the UPR and particularly of the IRE1/XBP1 signaling axis in Ph(+) ALL, while others demonstrated the therapeutic relevance of HSP70 in ALL. In this regard, HSP70 is regulated by smaller HSP40 s, whose function is so far poorly characterized. RESULTS: Herein, we characterize the expression of HSP40 s in Ph(+) ALL and CML. We show that these genes are not regulated in a pan-class manner and identify a homologous gene pair, namely Auxilin-1 (DNAJC6) and Auxilin-2 (GAK) with a unique expression profile. Overexpression of Auxilin-2, the ubiquitously expressed homologue of Auxilin-1 correlated with superior clinical outcome in ALL and was tightly linked to both IRE1 RNase and BCR-ABL1 kinase activities. CONCLUSIONS: Our findings suggest that HSP40 gens are uniquely regulated and provide a rationale for further studies between BCR-ABL1/IRE1-based therapies in combination with HSP40 inhibitors, thus opening potentially novel therapeutic avenues.