Reentrant semiconducting behavior in polymerized fullerite structures with increasing sp3-carbon content.

The electronic behavior of polymerized fullerite structures, ranging from one-dimensional to three-dimensional polymers, was studied using density functional theory with the hybrid Heyd-Scuseria-Ernzerhof functional and a 6-31G(d,p) basis set. The bandgap across these structures decreases with the rise of sp3-carbon content until metallic behavior is observed. A further increase induces a reopening of the bandgap, revealing a reentrant semiconducting behavior in this class of materials. This behavior is understood in terms of the new electronic states originated by polymeric bonding and the effect of the volume reduction on the dispersion of sp2-states. This study highlights the fullerite polymers as a magnificent platform to tune electronic properties.

Greater traditionalism predicts COVID-19 precautionary behaviors across 27 societies.

People vary both in their embrace of their society's traditions, and in their perception of hazards as salient and necessitating a response. Over evolutionary time, traditions have offered avenues for addressing hazards, plausibly resulting in linkages between orientations toward tradition and orientations toward danger. Emerging research documents connections between traditionalism and threat responsivity, including pathogen-avoidance motivations. Additionally, because hazard-mitigating behaviors can conflict with competing priorities, associations between traditionalism and pathogen avoidance may hinge on contextually contingent tradeoffs. The COVID-19 pandemic provides a real-world test of the posited relationship between traditionalism and hazard avoidance. Across 27 societies (N = 7844), we find that, in a majority of countries, individuals' endorsement of tradition positively correlates with their adherence to costly COVID-19-avoidance behaviors; accounting for some of the conflicts that arise between public health precautions and other objectives further strengthens this evidence that traditionalism is associated with greater attention to hazards.

Can we learn from errors? Retrieval facilitates the correction of false memories for pragmatic inferences.

Errorful learning suggests that, when perfect learning has not yet been attained, errors can enhance future learning if followed by corrective feedback. Research on memory updating has shown that after retrieval, memory becomes more malleable and prone to change. Thus, retrieval of a wrong answer might provide a good context for the incorporation of feedback. Here, we tested this hypothesis using sentences including pragmatic sentence implications, commonly used for the study of false memories. Across two experiments with young adults, we hypothesized that corrective feedback would be more efficient at reducing false memories if provided immediately after retrieval, when memory is more malleable than after being exposed to the material. Participants' memory was assessed as a function of the type of learning task (Experiment 1: retrieval vs. restudy; and Experiment 2: active vs. passive recognition); and whether participants received corrective feedback or not. In both experiments, we observed that retrieval not only improved correct recall (replicating the testing effect) but also promoted the correction of false memories. Notably, corrective feedback was more effective when given after errors that were committed during retrieval rather than after restudy (Experiment 1) or after passive recognition (Experiment 2). Our results suggest that the benefits of retrieval go beyond the testing effect since it also facilitates false memories correction. Retrieval seems to enhance memory malleability, thus improving the incorporation of feedback, compared to the mere presentation of the information. Our results support the use of learning strategies that engage in active and explicit retrieval because, even if the retrieved information is wrong-when immediate feedback is provided-memory updating is promoted and errors are more likely to be corrected.

Incidental exposure to hedonic and healthy food features affects food preferences one day later.

Memories acquired incidentally from exposure to food information in the environment may often become active to later affect food preferences. Because conscious use of these memories is not requested or required, these incidental learning effects constitute a form of indirect memory. In an experiment using a novel food preference paradigm (n = 617), we found that brief incidental exposure to hedonic versus healthy food features indirectly affected food preferences a day later, explaining approximately 10% of the variance in preferences for tasty versus healthy foods. It follows that brief incidental exposure to food information can affect food preferences indirectly for at least a day. When hedonic and health exposure were each compared to a no-exposure baseline, a general effect of hedonic exposure emerged across individuals, whereas health exposure only affected food preferences for high-BMI individuals. This pattern suggests that focusing attention on hedonic food features engages common affective processes across the general population, whereas focusing attention on healthy food features engages eating restraint goals associated with high BMI. Additionally, incidental exposure to food features primarily changed preferences for infrequently consumed foods, having less impact on habitually consumed foods. These findings offer insight into how hedonic information in the obesogenic food environment contributes to unhealthy eating behavior that leads to overweight and obesity. These findings further motivate the development of interventions that counteract the effects of exposure to hedonic food information and that broaden the effects of exposure to healthy food information.

Imagination Reduces False Memories for Everyday Action Sentences: Evidence From Pragmatic Inferences.

Human memory can be unreliable, and when reading a sentence with a pragmatic implication, such as "the karate champion hit the cinder block," people often falsely remember that the karate champion "broke" the cinder block. Yet, research has shown that encoding instructions affect the false memories we form. On the one hand, instructing participants to imagine themselves manipulating the to-be-recalled items increase false memories (imagination inflation effect). But on the other hand, instructions to imagine have reduced false memories in the DRM paradigm (imagination facilitation effect). Here, we explored the effect of imaginal encoding with pragmatic inferences, a way to study false memories for information about everyday actions. Across two experiments, we manipulated imaginal encoding through the instructions given to participants and the after-item filler task (none vs. math operations). In Experiment 1, participants were either assigned to the encoding condition of imagine+no filler; pay attention+math; or memorize+math. In Experiment 2, the encoding instructions (imagine vs. memorize) and the filler task (none vs. math) were compared across four separate conditions. Results from the two experiments showed that imagination instructions lead to better memory, by showing a higher proportion of correct responses and better performance in a memory benefit index. Similarly, a significant reduction of false memories was observed across both experiments, even though a complementary Bayesian analysis only supported this conclusion for Experiment 1. The findings show that imaginal encoding improves memory, suggesting the engagement of a distinctiveness heuristic and source-monitoring process.

3D phonon microscopy with sub-micron axial-resolution.

Brillouin light scattering (BLS) is an emerging method for cell imaging and characterisation. It allows elasticity-related contrast, optical resolution and label-free operation. Phonon microscopy detects BLS from laser generated coherent phonon fields to offer an attractive route for imaging since, at GHz frequencies, the phonon wavelength is sub-optical. Using phonon fields to image single cells is challenging as the signal to noise ratio and acquisition time are often poor. However, recent advances in the instrumentation have enabled imaging of fixed and living cells. This work presents the first experimental characterisation of phonon-based axial resolution provided by the response to a sharp edge. The obtained axial resolution is up to 10 times higher than that of the optical system used to take the measurements. Validation of the results are obtained with various polymer objects, which are in good agreement with those obtained using atomic force microscopy. Edge localisation, and hence profilometry, of a phantom boundary is measured with accuracy and precision of approximately 60 nm and 100 nm respectively. Finally, 3D imaging of fixed cells in culture medium is demonstrated.

Break the Ice: a Survey on Socially Aware Engagement for Human-Robot First Encounters.

Society is starting to come up with exciting applications for social robots like butlers, coaches, and waiters. However, these robots face a challenging task: to meet people during a first encounter. This survey explores the literature that contributes to this task. We define a taxonomy based on psychology and sociology models: Kendon's greeting model and Greenspan's model of social competence. We use Kendon's model as a framework to compare and analyze works that describe robotic systems that engage with people. To categorize individual skills, we use three components of Social Awareness that belong to Greenspan's model: Social Sensitivity, Social Insight, and Communication. Under each section, we highlight some research gaps and propose research directions to address them. Through our analysis, we suggest significant research directions for enhanced first encounters. First, social scripts need to be evaluated under equal conditions. Second, interaction management and tracking for first encounters should consider state and observation uncertainties. Third, perception methods need lighter and robust integration in mobile platforms. Fourth, methods to explicitly define social norms are still scarce. Finally, research on social feedback and interaction recovery may fill the gaps of imperfect first encounters.

Characterising the size and shape of metallic nano-structures by their acoustic vibrations.

The characterisation of metallic nano-structures is of great importance as their optical properties are strongly dependent on their size and shape. Inaccurate size or shape characterisation can result in misleading measurements in applications such as bio-imaging and sensing. Characterisation techniques such as dynamic light scattering, electron microscopy or atomic force microscopy are commonly used; however, performing sub-surface measurements (inside semi-transparent objects) or in liquid media are very challenging. Here, we use time-resolved pump-probe spectroscopy to characterise the size and shape of metallic nano-structures in a water surrounding medium by using their vibrational modes. We show that this technique can achieve size measurements with a precision of 3 nm for the largest nano-structures which are in agreement with electron microscopy images. Furthermore, we demonstrate the ability to probe individual nano-structures despite being located in the same optical point spread function (PSF). Combining the high precision and sub-optical measurements provided by this technique with the ability to insert metallic nano-structures inside biological samples might open a way to perform 3D characterisation measurements.

Learning what to inhibit: The influence of repeated testing on the encoding of gender and age information.

Psychological research has devoted considerable attention to the relationship between the multiple category dimensions that can be extracted from faces. In the present studies, we investigated the role of experience and learning on the way the social perceiver deals with multiple category dimensions. Specifically, we tested whether learning which of 2 dimensions is the most relevant to the task at hand influences the encoding and retrieval of both task-relevant and irrelevant dimensions. In our studies, participants went through several cycles, each consisting of a study and a test phase. We manipulated the structure of the tests such that participants were probed on only 1 category dimension (age or gender), despite viewing faces of both category dimensions in all study phases. We hypothesized that when participants were repeatedly tested on 1 dimension, they would proactively control their attention toward that specific dimension and away from the nonrelevant dimension. Five studies demonstrated that: (a) participants learned which dimension was test-relevant such that they gradually became faster and more accurate on that dimension; (b) when the gender dimension was test-relevant, participants were faster and more accurate retrieving information concerning the target faces' gender than age, while the opposite did not happen when the age dimension was test-relevant; and (c) this dominance of the gender dimension is mainly caused by the inhibition of the age dimension. Implications about the importance of previous experience and control for research on social categorization in general and research examining the interplay between gender and age are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

How Your Power Affects My Impression of You.

In the present article, we investigate how a person's power affects the way we infer traits from their behavior. In Experiment 1, our results suggest that, when faced with behavioral descriptions about others, participants infer both positive and negative traits about powerless actors, whereas for powerful and control (power irrelevant) actors, only positive but no negative traits are inferred, an effect we call the benevolence bias. In the second experiment, (a) we replicate this effect, (b) we show that it does not depend on the specific traits used in Experiment 1, and (c) we show that it is also detected when an implicit measure of inferences is used. Experiment 3 further shows that this effect generalizes to a more generic power manipulation. Theoretical explanations for these findings are discussed.

Memory and conceptual learning of relevant and non-relevant items in item-method directed forgetting.

The present research investigates the fate of non-target information when people are trying to either intentionally memorise or forget target information. By using an object-based attentional manipulation within a directed forgetting paradigm (item-method), we show a directed forgetting effect (DFE, i.e., better memory for to-be-remembered (TBR) than for to-be-forgotten (TBF) items) for items that participants are explicitly instructed to attend but not for irrelevant items that happen to be part of the context. Alongside the classic DFE, we investigate how the category of the attended and unattended items are learned. The results obtained in three experiments, show that people can successfully learn only the category of the TBR attended items and that the DFE extends to new items that are related to the old TBR and TBF items (an effect that we call conceptual DFE). These results give us new insight about how TBR and TBF items are processed and conceptually learned.

Off the top of my head: Malleability and stability in natural categories.

Previous research has found that category representations are highly malleable knowledge structures, varying widely across different contexts and individuals. However, it has also been found that such malleability does not apply equally to all types of category information. The present research further investigates the representational malleability versus stability of natural taxonomic categories. Using perceptual fluency as means to induce malleability, we explored whether malleability is moderated by the degree of typicality of category information. In the first experiment, we found that fluency-based malleability only occurs for non-typical category information. In follow-up experiments, we investigated the boundary conditions under which such fluency-based malleability occurs. Namely, in Experiment 2, we showed that the effect of fluency on non-typical features disappeared when there is a sensory modality mismatch between study and test phases. Finally, in Experiment 3, we demonstrated that this effect reappears in the modality mismatch condition when participants are given a response deadline. The implications of these findings to current theories of category representation and the perceptual fluency literature are discussed.

The future is now: the impact of present fluency in judgments about the future.

Recent research has emphasised the role of episodic memory in both remembering past events and in envisaging future events. On the other hand, it has been repeatedly shown that judgments about past events are affected by the fluency with which retrieval cues are processed. In this paper we investigate whether perceptual fluency also plays a role in judgments about future events. For this purpose we conducted four experiments. The first experiment replicated recent findings showing that stimuli that are processed fluently tend to be wrongly recognised as having been encountered in the past outside the laboratory walls [Brown, A. S., & Marsh, E. J. (2009). Creating illusions of past encounter through brief exposure. Psychological Science, 20, 534-538. doi: 10.1111/j.1467-9280.2009.02337.x ]. Two follow-up experiments using Brown and Marsh's [(2009). Creating illusions of past encounter through brief exposure. Psychological Science, 20, 534-538. doi: 10.1111/j.1467-9280.2009.02337 ] task tested the influence of perceptual fluency on future judgments. The fourth and last experiment was designed to rule out a potential confounding factor in the two previous experiments. Across experiments, we found that people rely on fluency when making judgments about events that are yet to come. These results suggest that fluency is an equally valid cue for past and future judgments.

Inferential Costs of Trait Centrality in Impression Formation: Organization in Memory and Misremembering.

An extension of the DRM paradigm was used to study the impact of central traits (Asch, 1946) in impression formation. Traits corresponding to the four clusters of the implicit theory of personality-intellectual, positive and negative; and social, positive and negative (Rosenberg et al., 1968)-were used to develop lists containing several traits of one cluster and one central trait prototypical of the opposite cluster. Participants engaging in impression formation relative to participants engaging in memorization not only produced higher levels of false memories corresponding to the same cluster of the list traits but, under response time pressure at retrieval, also produced more false memories of the cluster corresponding to the central trait. We argue that the importance of central traits stems from their ability to activate their corresponding semantic space within a specialized associative memory structure underlying the implicit theory of personality.

"To-be-forgotten" statements become less true: Memory processes involved in selection and forgetting lead to truthfulness changes of ambiguous sentences.

What happens when people try to forget something? What are the consequences of instructing people to intentionally forget a sentence? Recent studies employing the item-method directed forgetting paradigm have shown that to-be-forgotten (TBF) items are, in a subsequent task, emotionally devaluated relative to to-be-remembered (TBR) items, an aftereffect of memory selection (Vivas, Marful, Panagiotidou & Bajo, 2016). As such, distractor devaluation by attentional selection generalizes to memory selection. In this study, we use the item-method directed forgetting paradigm to test the effects of memory selection and inhibition on truth judgments of ambiguous sentences. We expected the relative standing of an item in the task (i.e., whether it was instructed to be remembered or forgotten) to affect the truthfulness value of that item, making TBF items less valid/truthful than TBR items. As predicted, ambiguous sentences associated with a "Forget" cue were subsequently judged as less true than sentences associated with a "Remember" cue, suggesting that instructions to intentionally forget a statement can produce changes in the validity/truthfulness of that statement. To our knowledge, this is the first study to show an influence of memory processes involved in selection and forgetting on the perceived truthfulness of sentences.

Explaining the persistence of false memories: a proposal based on associative activation and thematic extraction.

This study aimed to analyse the effect of retention intervals on associative and thematic false memories. Two experiments, using two types of critical items that were either associatively or thematically related to studied material, were conducted. In both experiments, one group of participants performed a recognition test immediately after the presentation of lists, and another group performed the task one week later. In Experiment 1, the recognition test consisted of pairs of items with four response alternatives (both items had been presented, only the left item had been presented, only the right item had been presented or none of the items had been presented). Critical items were also manipulated so that they were either presented in or absent from the list. In Experiment 2, a standard recognition test that differed in the mode of presentation was used: self-paced or speeded response. Both experiments showed that associative critical items were more recognised than thematic critical items in the immediate condition. However, whereas associative critical items decayed after a one-week delay, thematic critical items were similarly recognised at both retention intervals. The findings of the present study suggest that each type of process - associative and thematic - behave differently over time.

The memory of what we do not recall: dissociations and theoretical debates in the study of implicit memory

Implicit memory reflects itself on situations in which previously acquired information is expressed, without awareness or intention. The study of implicit memory has had a profound impact on how researchers have investigated the human memory. In this paper, we review the main studies which have revealed dissociations between direct and indirect tests of memory, and address the two main theoretical approaches used to explain these dissociations: the processing view and the multiple systems view. We then describe recent neuroscience studies and discuss its contributions to help clarify the debate about the mechanisms involved in explicit and implicit memory. Finally, we critically analyze some questions and controversies surrounding this literature, such as (a) the transparency assumption and the contamination issue; and (b) the theoretical utility of the dissociations. We emphasize that the biggest challenge for future research is to develop comprehensive theories that integrate behavioral and neuroscience findings (AU)

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High resolution 3D imaging of living cells with sub-optical wavelength phonons.

Label-free imaging of living cells below the optical diffraction limit poses great challenges for optical microscopy. Biologically relevant structural information remains below the Rayleigh limit and beyond the reach of conventional microscopes. Super-resolution techniques are typically based on the non-linear and stochastic response of fluorescent labels which can be toxic and interfere with cell function. In this paper we present, for the first time, imaging of live cells using sub-optical wavelength phonons. The axial imaging resolution of our system is determined by the acoustic wavelength (λa = λprobe/2n) and not on the NA of the optics allowing sub-optical wavelength acoustic sectioning of samples using the time of flight. The transverse resolution is currently limited to the optical spot size. The contrast mechanism is significantly determined by the mechanical properties of the cells and requires no additional contrast agent, stain or label to image the cell structure. The ability to breach the optical diffraction limit to image living cells acoustically promises to bring a new suite of imaging technologies to bear in answering exigent questions in cell biology and biomedicine.

Evaluating young and old faces on social dimensions: trustworthiness and dominance

In the present study we provide measures of dominance and trustworthiness of a subset of faces from the Productive Aging Laboratory (PAL) Face Database (Minear & Park, 2004). Recent research has shown that dominance and trustworthiness are central to social perception, and that they can be inferred from faces in milliseconds (Oosterhof & Todorov, 2008). A total of 286 faces from four age groups (18-29; 30-49; 50-69; 70-94) were presented and evaluated in dominance and trustworthiness. The same faces were also evaluated on other four dimensions: likeability, perceived age, attractiveness, and gender typicality. This information enriches the PAL Face Database, making it more valuable for researchers investigating faceprocessing mechanisms across the lifespan. The collected norms are available for download as supplemental materials (AU)

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