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People's negative attitudes to vaccines can be motivated by psychological factors—such as fears, ideological beliefs, and cognitive patterns—known as 'attitude roots'. This study had two primary objectives: (1) to identify which of 11 known attitude roots are featured in individuals' self-expressed reasons for negative vaccine attitudes (i.e., a linguistic analysis); (2) to explore how attitude roots present in self-expressed texts are linked to specific psychological measures. To achieve Objective 1, our study collected data from December 2022 to January 2023 from 556 participants from the US, who wrote texts to explain the reasons for their negative vaccine attitudes. The texts encompassed 2327 conceptually independent units of anti-vaccination argumentation, that were each coded for its attitude root(s) by at least two psychological experts. By allowing participants to spontaneously express their attitudes in their own words, we were able to observe how this differed from what participants reported to endorse when presented with a list of arguments. We found that there were four groups of attitude roots based on linguistic similarity in self-expression. In addition, latent class analysis of participants' coded texts identified three distinct groups of participants that were characterised by their tendency to express combinations of arguments related to (1) fears, (2) anti-scientific conceptions, and (3) politicised perspectives. To achieve Objective 2, we collected participants' responses to 11 validated measures of psychological constructs expected to underlie the respective 11 attitude roots, and used a correlational design to investigate how participants' self-expressed attitude roots were linked to these measures. Logistic regressions showed that an expected psychological construct was the strongest, and significant, predictor for expression of three out of the four attitude root groups. We discuss the implications of these findings for health communicators and practitioners. [ABSTRACT FROM AUTHOR]

In today’s polarized political climate, researchers who combat mistruths have come under attack and been labelled as unelected arbiters of truth. But the fight against misinformation is valid, warranted and urgently required. [ABSTRACT FROM AUTHOR]

The proliferation of anti-vaccination arguments online can threaten immunisation programmes, including those targeting COVID-19. To effectively refute misinformed views about vaccination, communicators need to go beyond providing correct information and debunking of misconceptions, and must consider the underlying motivations of people who hold contrarian views. Drawing on a taxonomy of anti-vaccination arguments that identified 11 "attitude roots"—i.e., psychological attributes—that motivate an individual's vaccine-hesitant attitude, we assessed whether these attitude roots were identifiable in argument endorsements and responses to psychological construct measures corresponding to the presumed attitude roots. In two UK samples (total n = 1250), we found that participants exhibited monological belief patterns in their highly correlated endorsements of anti-vaccination arguments drawn from different attitude roots, and that psychological constructs representing the attitude roots significantly predicted argument endorsement strength and vaccine hesitancy. We identified four different latent anti-vaccination profiles amongst our participants' responses. We conclude that endorsement of anti-vaccination arguments meaningfully dovetails with attitude roots clustering around anti-scientific beliefs and partisan ideologies, but that the balance between those attitudes differs considerably between people. Communicators must be aware of those individual differences. [ABSTRACT FROM AUTHOR]

This Comment piece summarises current challenges regarding routine vaccine uptake in the context of the COVID-19 pandemic and provides recommendations on how to increase uptake. To implement these recommendations, the article points to evidence-based resources that can support health-care workers, policy makers and communicators. [ABSTRACT FROM AUTHOR]

Given that being misinformed can have negative ramifications, finding optimal corrective techniques has become a key focus of research. In recent years, several divergent correction formats have been proposed as superior based on distinct theoretical frameworks. However, these correction formats have not been compared in controlled settings, so the suggested superiority of each format remains speculative. Across four experiments, the current paper investigated how altering the format of corrections influences people's subsequent reliance on misinformation. We examined whether myth-first, fact-first, fact-only, or myth-only correction formats were most effective, using a range of different materials and participant pools. Experiments 1 and 2 focused on climate change misconceptions; participants were Qualtrics online panel members and students taking part in a massive open online course, respectively. Experiments 3 and 4 used misconceptions from a diverse set of topics, with Amazon Mechanical Turk crowdworkers and university student participants. We found that the impact of a correction on beliefs and inferential reasoning was largely independent of the specific format used. The clearest evidence for any potential relative superiority emerged in Experiment 4, which found that the myth-first format was more effective at myth correction than the fact-first format after a delayed retention interval. However, in general it appeared that as long as the key ingredients of a correction were presented, format did not make a considerable difference. This suggests that simply providing corrective information, regardless of format, is far more important than how the correction is presented. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has seen one of the first large-scale uses of digital contact tracing to track a chain of infection and contain the spread of a virus. The new technology has posed challenges both for governments aiming at high and effective uptake and for citizens weighing its benefits (e.g., protecting others' health) against the potential risks (e.g., loss of data privacy). Our cross-sectional survey with repeated measures across four samples in Germany ( N = 4357 ) focused on psychological factors contributing to the public adoption of digital contact tracing. We found that public acceptance of privacy-encroaching measures (e.g., granting the government emergency access to people's medical records or location tracking data) decreased over the course of the pandemic. Intentions to use contact tracing apps—hypothetical ones or the Corona-Warn-App launched in Germany in June 2020—were high. Users and non-users of the Corona-Warn-App differed in their assessment of its risks and benefits, in their knowledge of the underlying technology, and in their reasons to download or not to download the app. Trust in the app's perceived security and belief in its effectiveness emerged as psychological factors playing a key role in its adoption. We incorporate our findings into a behavioral framework for digital contact tracing and provide policy recommendations. [ABSTRACT FROM AUTHOR]

We report the results of a preregistered study that tested the effectiveness of inoculating participants against Islamophobic and radical-Islamist disinformation. Participants in the experimental (inoculation) condition watched a video that explained common rhetorical markers of radical-Islamist and Islamophobic disinformation that had been identified in an analysis of YouTube content. The information was presented in a neutral context not involving Islam and focused on analysis of the misleading argumentation. The control group watched a video about an unrelated topic. Participants were then exposed to target videos with "gateway" content that constituted an entry point to potential Islamist or Islamophobic radicalization. Both videos contained numerous items of disinformation. Participants then answered a variety of questions such as how likely they were to share the video, their level of agreement, and their perceived accuracy of the video. Participants who had received the inoculation displayed less agreement with the video content, perceived the video as less reliable, and were less likely to share it in comparison with participants in the control group. The study provides support for the use of argument-based inoculation in combatting extremist messages. [ABSTRACT FROM AUTHOR]

Online platforms' data give advertisers the ability to "microtarget" recipients' personal vulnerabilities by tailoring different messages for the same thing, such as a product or political candidate. One possible response is to raise awareness for and resilience against such manipulative strategies through psychological inoculation. Two online experiments (total N = 828 ) demonstrated that a short, simple intervention prompting participants to reflect on an attribute of their own personality—by completing a short personality questionnaire—boosted their ability to accurately identify ads that were targeted at them by up to 26 percentage points. Accuracy increased even without personalized feedback, but merely providing a description of the targeted personality dimension did not improve accuracy. We argue that such a "boosting approach," which here aims to improve people's competence to detect manipulative strategies themselves, should be part of a policy mix aiming to increase platforms' transparency and user autonomy. [ABSTRACT FROM AUTHOR]

Political scientists have conventionally assumed that achieving democracy is a one-way ratchet. Only very recently has the question of "democratic backsliding" attracted any research attention. We argue that democratic instability is best understood with tools from complexity science. The explanatory power of complexity science arises from several features of complex systems. Their relevance in the context of democracy is discussed. Several policy recommendations are offered to help (re)stabilize current systems of representative democracy. [ABSTRACT FROM AUTHOR]

There is a broad agreement that psychology is facing a replication crisis. Even some seemingly well-established findings have failed to replicate. Numerous causes of the crisis have been identified, such as underpowered studies, publication bias, imprecise theories, and inadequate statistical procedures. The replication crisis is real, but it is less clear how it should be resolved. Here we examine potential solutions by modeling a scientific community under various different replication regimes. In one regime, all findings are replicated before publication to guard against subsequent replication failures. In an alternative regime, individual studies are published and are replicated after publication, but only if they attract the community's interest. We find that the publication of potentially non-replicable studies minimizes cost and maximizes efficiency of knowledge gain for the scientific community under a variety of assumptions. Provided it is properly managed, our findings suggest that low replicability can support robust and efficient science. There has been much concern about the "replication crisis" in psychology and other disciplines. Here the authors show that an efficient solution to the crisis would not insist on replication before publication, and would instead encourage publication before replication, with the findings marked as preliminary. [ABSTRACT FROM AUTHOR]

Internet blogs have become an important platform for the discussion of many scientific issues, including climate change. Blogs, and in particular the comment sections of blogs, also play a major role in the dissemination of contrarian positions that question mainstream climate science. The effect of this content on people's attitudes is not fully understood. In particular, it is unknown how the interaction between the content of blog posts and blog comments affects readers' attitudes. We report an experiment that orthogonally varied those two variables using blog posts and comments that either did, or did not, support the scientific consensus on climate change. We find that beliefs are partially shaped by readers' perception of how widely an opinion expressed in a blog post appears to be shared by other readers. The perceived social consensus among readers, in turn, is determined by whether blog comments endorse or reject the contents of a post. When comments reject the content, perceived reader consensus is lower than when comments endorse the content. The results underscore the importance of perceived social consensus on opinion formation. [ABSTRACT FROM AUTHOR]

A worrying number of psychological findings are not replicable. Diagnoses of the causes of this "replication crisis," and recommendations to address it, have nearly exclusively focused on methods of data collection, analysis, and reporting. We argue that a further cause of poor replicability is the often weak logical link between theories and their empirical tests. We propose a distinction between discovery-oriented and theory-testing research. In discovery-oriented research, theories do not strongly imply hypotheses by which they can be tested, but rather define a search space for the discovery of effects that would support them. Failures to find these effects do not question the theory. This endeavor necessarily engenders a high risk of Type I errors—that is, publication of findings that will not replicate. Theory-testing research, by contrast, relies on theories that strongly imply hypotheses, such that disconfirmation of the hypothesis provides evidence against the theory. Theory-testing research engenders a smaller risk of Type I errors. A strong link between theories and hypotheses is best achieved by formalizing theories as computational models. We critically revisit recommendations for addressing the "replication crisis," including the proposal to distinguish exploratory from confirmatory research, and the preregistration of hypotheses and analysis plans. [ABSTRACT FROM AUTHOR]

Science strives for coherence. For example, the findings from climate science form a highly coherent body of knowledge that is supported by many independent lines of evidence: greenhouse gas (GHG) emissions from human economic activities are causing the global climate to warm and unless GHG emissions are drastically reduced in the near future, the risks from climate change will continue to grow and major adverse consequences will become unavoidable. People who oppose this scientific body of knowledge because the implications of cutting GHG emissions-such as regulation or increased taxation-threaten their worldview or livelihood cannot provide an alternative view that is coherent by the standards of conventional scientific thinking. Instead, we suggest that people who reject the fact that the Earth's climate is changing due to greenhouse gas emissions (or any other body of well-established scientific knowledge) oppose whatever inconvenient finding they are confronting in piece-meal fashion, rather than systematically, and without considering the implications of this rejection to the rest of the relevant scientific theory and findings. Hence, claims that the globe 'is cooling' can coexist with claims that the 'observed warming is natural' and that 'the human influence does not matter because warming is good for us.' Coherence between these mutually contradictory opinions can only be achieved at a highly abstract level, namely that 'something must be wrong' with the scientific evidence in order to justify a political position against climate change mitigation. This high-level coherence accompanied by contradictory subordinate propositions is a known attribute of conspiracist ideation, and conspiracism may be implicated when people reject well-established scientific propositions. [ABSTRACT FROM AUTHOR]

Among papers stating a position on anthropogenic global warming (AGW), 97 % endorse AGW. What is happening with the 2 % of papers that reject AGW? We examine a selection of papers rejecting AGW. An analytical tool has been developed to replicate and test the results and methods used in these studies; our replication reveals a number of methodological flaws, and a pattern of common mistakes emerges that is not visible when looking at single isolated cases. Thus, real-life scientific disputes in some cases can be resolved, and we can learn from mistakes. A common denominator seems to be missing contextual information or ignoring information that does not fit the conclusions, be it other relevant work or related geophysical data. In many cases, shortcomings are due to insufficient model evaluation, leading to results that are not universally valid but rather are an artifact of a particular experimental setup. Other typical weaknesses include false dichotomies, inappropriate statistical methods, or basing conclusions on misconceived or incomplete physics. We also argue that science is never settled and that both mainstream and contrarian papers must be subject to sustained scrutiny. The merit of replication is highlighted and we discuss how the quality of the scientific literature may benefit from replication. [ABSTRACT FROM AUTHOR]

The Hebb repetition effect refers to the finding that immediate serial recall is improved over trials for memory lists that are surreptitiously repeated across trials, relative to new lists. We show in four experiments that the Hebb repetition effect is also observed with a complex-span task, in which encoding or retrieval of list items alternates with an unrelated processing task. The interruption of encoding or retrieval by the processing task did not reduce the size of the Hebb effect, demonstrating that incidental long-term learning forms integrated representations of lists, excluding the interleaved processing events. Contrary to the assumption that complex-span performance relies more on long-term memory than standard immediate serial recall (simple span), the Hebb effect was not larger in complex-span than in simple-span performance. The Hebb effect in complex span was also not modulated by the opportunity for refreshing list items, questioning a role of refreshing for the acquisition of the long-term memory representations underlying the effect. [ABSTRACT FROM AUTHOR]

The question of how climate model projections have tracked the actual evolution of global mean surface air temperature is important in establishing the credibility of their projections. Some studies and the IPCC Fifth Assessment Report suggest that the recent 15-year period (1998-2012) provides evidence that models are overestimating current temperature evolution. Such comparisons are not evidence against model trends because they represent only one realization where the decadal natural variability component of the model climate is generally not in phase with observations. We present a more appropriate test of models where only those models with natural variability (represented by El Niño/Southern Oscillation) largely in phase with observations are selected from multi-model ensembles for comparison with observations. These tests show that climate models have provided good estimates of 15-year trends, including for recent periods and for Pacific spatial trend patterns. [ABSTRACT FROM AUTHOR]

Uncertainty forms an integral part of climate science, and it is often used to argue against mitigative action. This article presents an analysis of uncertainty in climate sensitivity that is robust to a range of assumptions. We show that increasing uncertainty is necessarily associated with greater expected damages from warming, provided the function relating warming to damages is convex. This constraint is unaffected by subjective or cultural risk-perception factors, it is unlikely to be overcome by the discount rate, and it is independent of the presumed magnitude of climate sensitivity. The analysis also extends to 'second-order' uncertainty; that is, situations in which experts disagree. Greater disagreement among experts increases the likelihood that the risk of exceeding a global temperature threshold is greater. Likewise, increasing uncertainty requires increasingly greater protective measures against sea level rise. This constraint derives directly from the statistical properties of extreme values. We conclude that any appeal to uncertainty compels a stronger, rather than weaker, concern about unabated warming than in the absence of uncertainty. [ABSTRACT FROM AUTHOR]

In public debate surrounding climate change, scientific uncertainty is often cited in connection with arguments against mitigative action. This article examines the role of uncertainty about future climate change in determining the likely success or failure of mitigative action. We show by Monte Carlo simulation that greater uncertainty translates into a greater likelihood that mitigation efforts will fail to limit global warming to a target (e.g., 2 °C). The effect of uncertainty can be reduced by limiting greenhouse gas emissions. Taken together with the fact that greater uncertainty also increases the potential damages arising from unabated emissions (Lewandowsky et al. ), any appeal to uncertainty implies a stronger, rather than weaker, need to cut greenhouse gas emissions than in the absence of uncertainty. [ABSTRACT FROM AUTHOR]

Misinformation-defined as information that is initially assumed to be valid but is later corrected or retracted-often has an ongoing effect on people's memory and reasoning. We tested the hypotheses that (a) reliance on misinformation is affected by people's preexisting attitudes and (b) attitudes determine the effectiveness of retractions. In two experiments, participants scoring higher and lower on a racial prejudice scale read a news report regarding a robbery. In one scenario, the suspects were initially presented as being Australian Aboriginals, whereas in a second scenario, a hero preventing the robbery was introduced as an Aboriginal person. Later, these critical, race-related pieces of information were or were not retracted. We measured participants' reliance on misinformation in response to inferential reasoning questions. The results showed that preexisting attitudes influence people's use of attitude-related information but not the way in which a retraction of that information is processed. [ABSTRACT FROM AUTHOR]

Sequential dependencies can provide valuable information about the processes supporting memory, particularly memory for serial order. Earlier analyses have suggested that anticipation errors-reporting items ahead of their correct position in the sequence-tend to be followed by recall of the displaced item, consistent with primacy gradient models of serial recall. However, a more recent analysis instead suggests that anticipation errors are followed by further anticipation errors, consistent with chaining models. We report analyses of 21 conditions from published serial recall data sets, in which we observed a systematic pattern whereby anticipations tended to be followed by the 'filling in' of displaced items. We note that cases where a different pattern held tended to apply to recall of longer lists under serial learning conditions or to conditions where participants were free to skip over items. Although the different patterns that can be observed might imply a dissociation (e.g., between short- and long-term memory), we show that these different patterns are naturally predicted by Farrell's (Psychological Review 119:223-271, ) model of short-term and episodic memory and relate to whether or not spontaneously formed groups of items can be skipped over during recall. [ABSTRACT FROM AUTHOR]

Although most experts agree that CO2 emissions are causing anthropogenic global warming (AGW), public concern has been declining. One reason for this decline is the 'manufacture of doubt' by political and vested interests, which often challenge the existence of the scientific consensus. The role of perceived consensus in shaping public opinion is therefore of considerable interest: in particular, it is unknown whether consensus determines people's beliefs causally. It is also unclear whether perception of consensus can override people's 'worldviews', which are known to foster rejection of AGW. Study 1 shows that acceptance of several scientific propositions-from HIV/AIDS to AGW-is captured by a common factor that is correlated with another factor that captures perceived scientific consensus. Study 2 reveals a causal role of perceived consensus by showing that acceptance of AGW increases when consensus is highlighted. Consensus information also neutralizes the effect of worldview. [ABSTRACT FROM AUTHOR]

This article introduces a new computational model for the complex-span task, the most popular task for studying working memory. SOB-CS is a two-layer neural network that associates distributed item representations with distributed, overlapping position markers. Memory capacity limits are explained by interference from a superposition of associations. Concurrent processing interferes with memory through involuntary encoding of distractors. Free time in-between distractors is used to remove irrelevant representations, thereby reducing interference. The model accounts for benchmark findings in four areas: (1) effects of processing pace, processing difficulty, and number of processing steps; (2) effects of serial position and error patterns; (3) effects of different kinds of item-distractor similarity; and (4) correlations between span tasks. The model makes several new predictions in these areas, which were confirmed experimentally. [ABSTRACT FROM AUTHOR]

Serial recall is often assumed to involve response suppression: the removal or inhibition of items already recalled so that they are not recalled again. Evidence for response suppression includes repetition inhibition and the separation of erroneous repetitions. Some theorists have suggested that response suppression, by eliminating competing responses, also contributes to recency in forward serial recall. We present experiments in which performance on the final item was examined as a function of whether or not the preceding retrievals entailed suppression of potential response competitors. In line with the predictions of response suppression, recency was found to be reduced when the earlier recall errors consisted of intrusion errors (which leave list items unsuppressed) rather than transposition errors (which involve suppression). [ABSTRACT FROM AUTHOR]

Information that is presumed to be true at encoding but later on turns out to be false (i.e., misinformation) often continues to influence memory and reasoning. In the present study, we investigated how the strength of encoding and the strength of a later retraction of the misinformation affect this continued influence effect. Participants read an event report containing misinformation and a subsequent correction. Encoding strength of the misinformation and correction were orthogonally manipulated either via repetition (Experiment 1) or by imposing a cognitive load during reading (Experiment 2). Results suggest that stronger retractions are effective in reducing the continued influence effects associated with strong misinformation encoding, but that even strong retractions fail to eliminate continued influence effects associated with relatively weak encoding. We present a simple computational model based on random sampling that captures this effect pattern, and conclude that the continued influence effect seems to defy most attempts to eliminate it. [ABSTRACT FROM AUTHOR]

Working memory is a core concept in cognition, predicting about 50% of the variance in IQ and reasoning tasks. A popular test of working memory is the complex span task, in which encoding of memoranda alternates with processing of distractors. A recent model of complex span performance, the Time-Based-Resource-Sharing (TBRS) model of Barrouillet and colleagues, has seemingly accounted for several crucial findings, in particular the intricate trade-off between deterioration and restoration of memory in the complex span task. According to the TBRS, memory traces decay during processing of the distractors, and they are restored by attentional refreshing during brief pauses in between processing steps. However, to date, the theory has been formulated only at a verbal level, which renders it difficult to test and to be certain of its intuited predictions. We present a computational instantiation of the TBRS and show that it can handle most of the findings on which the verbal model was based. We also show that there are potential challenges to the model that await future resolution. This instantiated model, TBRS*, is the first comprehensive computational model of performance in the complex span paradigm. The Matlab model code is available as a supplementary material of this article. [ABSTRACT FROM AUTHOR]

Information that initially is presumed to be correct, but that is later retracted or corrected, often continues to influence memory and reasoning. This occurs even if the retraction itself is well remembered. The present study investigated whether the continued influence of misinformation can be reduced by explicitly warning people at the outset that they may be misled. A specific warning--giving detailed information about the continued influence effect (CIE)--succeeded in reducing the continued reliance on outdated information but did not eliminate it. A more general warning--reminding people that facts are not always properly checked before information is disseminated--was even less effective. In an additional experiment, a specific warning was combined with the provision of a plausible alternative explanation for the retracted information. This combined manipulation further reduced the CIE but still failed to eliminate it altogether. [ABSTRACT FROM AUTHOR]

Recent temporal distinctiveness models of memory predict that temporally isolated items will be recalled better than temporally crowded items. The effect has been found in some tasks (free recall, memory for serial order when report order is unconstrained, running memory span) but not in others (forward serial recall). Such results suggest that the attentional weighting given to a temporal dimension in memory may vary with task demands. Here, we find robust temporal isolation effects in recognition memory (Experiment 1) and a smaller isolation effect in forward serial recall when an open pool of items is used (Experiment 2). Analysis of 26 temporal isolation effects suggests that the phenomenon occurs in a range of tasks but is larger when it is useful to attend to a temporal dimension in memory. The overall pattern of results is taken to favor memory models that rely on multiple weighted dimensions in memory, one of which is temporal. [ABSTRACT FROM AUTHOR]

We present a battery of four working memory tasks that are implemented using MATLAB and the free Psychophysics Toolbox. The package includes preprocessing scripts in R and SPSS to facilitate data analysis. The four tasks consist of a sentence-span task, an operation-span task, a spatial short-term memory test, and a memory updating task. These tasks were chosen in order to provide a heterogeneous set of measures of working memory capacity, thus reducing method variance and tapping into two content domains of working memory (verbal, including numerical, vs. spatial) and two of its functional aspects (storage in the context of processing and relational integration). The task battery was validated in three experiments conducted in two languages ( English and Chinese), involving more than 350 participants. In all cases, the tasks were found to load on a single latent variable. In a further experiment, the latent working memory variable was found to correlate highly but not perfectly with performance on Raven's matrices test of fluid intelligence. We suggest that the battery constitutes a versatile tool to assess working memory capacity with either English- or Chinese-speaking participants. The battery can be downloaded from www.cogsciwa.com ("Software" button). [ABSTRACT FROM AUTHOR]

How do people report the contents of short-term memory when information about order must be retained but items can be retrieved in any order? We report an experiment using an unconstrained reconstruction task in which people can report list items in any order but must place them in their correct serial positions. We found (1) a tendency to report recent items first in immediate but not in delayed reconstruction, (2) a tendency to recall temporally isolated items first, (3) a preference for forward recall order, and (4) a preference for output orders that minimize the length of the path that must be traversed through memory space during retrieval. The results constrain most current models of short-term memory in which retrieval is ballistic and is assumed to run to completion autonomously once initiated. [ABSTRACT FROM AUTHOR]

In numerous recent studies in short-term memory, it has been established that forward serial recall is unaffected by the temporal isolation of to-be-remembered items. These findings contradict the temporal distinctiveness view of memory, which expects items that are temporally isolated from their neighbors to be more distinct and hence remembered better. To date, isolation effects have only been found with tests that do not constrain output order, such as free recall. This article reports two experiments that, for the first time, report a temporal isolation effect with forward serial recall, using a running memory task in which the end of the list is unpredictable. The results suggest that people are able to encode and use temporal information in situations in which positional information is of little value. We conclude that the overall pattern of findings concerning temporal isolation supports models of short-term memory that postulate multidimensional representations of items. [ABSTRACT FROM AUTHOR]

The processes that determine unsupervised categorization, the task of classifying stimuli without guidance or feedback, are poorly understood. Two experiments examined the emergence and plasticity of unsupervised strategies using perceptual stimuli that varied along two separable dimensions. In the first experiment, participants either classified stimuli into any two categories of their choice or learned identical classifications by supervised categorization. Irrespective of the complexity of classification, supervised and unsupervised learning rates differed little when both modes of learning were maximally comparable. The second experiment examined the plasticity of unsupervised classifications by introducing novel stimuli halfway through training. Whether or not people altered their strategies, they responded to novel stimuli in a gradual manner. The gradual and continuous evolution and adaptation of strategies suggests that unsupervised categorization involves true learning which shares many properties of supervised category learning. We also show that the choice of unsupervised strategy cannot be predicted from the properties of early learning trials, but is best understood as a function of the initial distribution of dimensional attention. [ABSTRACT FROM AUTHOR]

Knowledge partitioning refers to the notion that knowledge can be held in independent and non-overlapping parcels. Partitioned knowledge may cause people to make contradictory decisions for identical problems in different circumstances. We report two experiments that explored the boundary conditions of knowledge partitioning in categorization. The studies examined whether or not people would partition their knowledge (1) when categorization rules were or were not verbalizable and (2) when the to-be-categorized stimuli comprised perceptually separable or integral dimensions. When learning difficulty was controlled, partitioning occurred across all combinations of verbalizability and integrality/separability, underscoring the generality of knowledge partitioning. Partitioning was absent only when the task was rapidly learned and people reached a high level of proficiency, suggesting that task difficulty plays a critical role in the emergence of partitioned knowledge. [ABSTRACT FROM AUTHOR]

Participants learned to classify seemingly arbitrary words into categories that also corresponded to ad hoc categories (see, e.g., Barsalou, 1983). By adapting experimental mechanisms previously used to study knowledge restructuring in perceptual categorization, we provide a novel account of how experimental and preexperimental knowledge interact. Participants were told of the existence of the ad hoc categories either at the beginning or the end of training. When the ad hoc labels were revealed at the end of training, participants switched from categorization based on experimental learning to categorization based on preexperimental knowledge in some, but not all, circumstances. Important mediators of the extent of that switch were the amount of performance error experienced during prior learning and whether or not prior knowledge was in conflict with experimental learning. We present a computational model of the trade-off between preexperimental knowledge and experimental learning that accounts for the main results. [ABSTRACT FROM AUTHOR]

The notion of a link between time and memory is intuitively appealing and forms the core assumption of temporal distinctiveness models. Distinctiveness models predict that items that are temporally isolated from their neighbors at presentation should be recalled better than items that are temporally crowded. By contrast, event-based theories consider time to be incidental to the processes that govern memory and such theories would not imply a temporal isolation advantage unless participants engaged in a consolidation process (e.g., rehearsal or selective encoding) that exploited the temporal structure of the list. In this report, we examine two studies that assessed the effect of temporal distinctiveness on memory, using auditory (Experiment 1) and auditory and visual (Experiment 2) presentation with unpredictably varying interitem intervals. The results show that with unpredictable intervals temporal isolation does not benefit memory, regardless of presentation modality. [ABSTRACT FROM AUTHOR]

Abstract Short-term serial recall performance is strongly affected by the nature of the items to be remembered. For example, memory span declines with decreasing speech rate (i.e., increasing pronunciation duration) of the items and, for a given speech rate, memory for non-words is poorer than for words. Similarly, words of high natural language frequency are recalled better than low-frequency words. Existing descriptive models have identified redintegration as underlying many of those effects. Redintegration refers to the process by which partially retrieved memorial information is converted into an overt response. This article presents a process model of redintegration based on a non-linear dynamic network, which is shown to handle the effects of speech rate, lexicality, and word frequency on memory span. Unlike previous descriptive efforts, the redintegration model also predicts the shape of the underlying serial position curves. [ABSTRACT FROM AUTHOR]

Explores the limitations of expertise in the prediction and control of bush fires. Dependence of experts' behavior on problem context; Occurrence of systematic behavior in some domain-relevant problems when presented in one particular context; Classification of utterances relating to fire prediction.

Presents the results of a trial in simultaneous Internet and videoconferencing delivery of an introductory cognitive science laboratory in Australia. Factors of communication mode, channel types and communication structure; Nature of material to be learned as basis for selection of medium for delivery; Use of BrainWave simulator.

Discusses the role of context in repetition priming using a lexical decision task. Priming as a function of perceived sense of a nonhomographic target word; Sense-specific activation framework in reference to a modified processing view.

According to Tversky and Kahneman's (1973) availability heuristic, people sometimes make use of the ease with which instances are retrieved when they have to estimate proportions or frequencies. One implication of this availability heuristic is that any factor that affects memorability of instances from a category should also affect the estimated category size. In one of their experiments, Tversky and Kahneman found that, after being presented with a list of names, people judged the more famous names to be more frequent. Similarly, recall was found to be greater for the more famous names. Three experiments that used Tversky and Kahneman's paradigm are reported. Repeating nonfamous names resulted in their increased recallability and a corresponding increase in estimates of their frequency (Experiments 1 and 3). Making nonfamous names more salient (Experiment 3) also had parallel effects on recallability and frequency estimates, indicating that different memory manipulations affected availability in a similar fashion. Furthermore, reliance on the heuristic was not changed as a function of prior knowledge (Experiment 2) or practice (Experiment 3) [ABSTRACT FROM AUTHOR]