Evaluating source credibility effects in health labelling using vending machines in a hospital setting.

OBJECTIVES: Providing advice to consumers in the form of labelling may mitigate the increased availability and low cost of foods that contribute to the obesity problem. Our objective was to test whether making the source of the health advice on the label more credible makes labelling more effective. METHODS AND MEASURES: Vending machines in different locations were stocked with healthy and unhealthy products in a hospital. Healthy products were randomly assigned to one of three conditions (i) a control condition in which no labelling was present (ii) a low source credibility label, "Lighter choices", and (iii) a high source credibility label that included the UK National Health Service (NHS) logo and name, "NHS lighter choices". Unhealthy products received no labelling. The outcome measure was sales volume. RESULTS: There were no main effects of labelling. However, there were significant interactions between labelling, vending machine location and payment type. For one location and payment type, sales of products increased in the high credibility label condition compared to control, particularly for unhealthy products, contrary to expectations. CONCLUSIONS: Our findings suggest that high source credibility health labels (NHS endorsement) on food either have little effect, or worse, can "backfire" and lead to effects opposite to those intended. The primary limitations are the limited range of source credibility labels and the scale of the study.

Identifying reasons for non-acceptance of influenza vaccine in healthcare workers: an observational study using declination form data.

BACKGROUND: Healthcare workers are sometimes required to complete a declination form if they choose not to accept the influenza vaccine. We analysed the declination data with the goal of identifying barriers to vaccination uptake across seasons, staff groups, and pre- and post- arrival of COVID-19. METHODS: Reasons for declining the vaccine were gathered from N = 2230 declination forms, collected over four influenza seasons, 2017/2018, 2018/2019, 2019/2020 and 2020/2021, from a single health board in the UK. Reasons were classified according to ten categories and the resulting distribution analysed across year and staff groups. A further analysis considered the two most prevalent categories in more detail. RESULTS: Fear of adverse reactions and Lack of perception of own risk were identified as primary reasons for not accepting the vaccine across time and across staff groups. However, there was no evidence that Lack of concern with influenza, or Doubts about vaccine efficacy was prevalent, contrary to previous findings. Overall, reasons fitted a pattern of underestimating risk associated with influenza and overestimating risk of minor adverse reactions. There were also differences across years, χ2(24) = 123, p < .001. In particular, there were relatively fewer Lack of perception of own risk responses post-COVID-19 arrival than before, χ2(8) = 28.93, p = .002. CONCLUSION: This study shows that data collected from declination forms yields sensible information concerning vaccine non-acceptance without the difficulties of retrospective or pre-emptive reasoning suffered by questionnaires. Our findings will aid messaging campaigns designed to encourage uptake of the influenza vaccine in healthcare workers. In particular, we argue for an approach focused on risk perception rather than correction of straightforward misconceptions.

Priming scalar and ad hoc enrichment in children.

Sentences can be enriched by considering what the speaker does not say but could have done. Children, however, struggle to derive one type of such enrichments, scalar implicatures. A popular explanation for this, the lexical alternatives account, is that they do not have lexical knowledge of the appropriate alternatives to generate the implicature. Namely, children are unaware of the scalar relationship between some and all. We conducted a priming study with N = 72 children, aged 5;1 years, and an adult sample, N = 51, to test this hypothesis. Participants were exposed to prime trials of strong, alternative, or weak sentences involving scalar or ad hoc expressions, and then saw a target trial that could be interpreted in either way. Consistent with previous studies, children were reluctant to derive scalar implicatures. However, there were two novel findings. (1) Children responded with twice the rate of ad hoc implicature responses than adults, suggesting that the implicature was the developmentally prior interpretation for ad hoc expressions. (2) Children showed robust priming effects, suggesting that children are aware of the scalar relationship between some and all, even if they choose not to derive the implicature. This suggests that the root cause of the scalar implicature deficit is not due to the absence of lexical knowledge of the relationship between some and all.

Salient alternatives facilitate implicatures.

Sentences can be enriched by considering what the speaker does not say but could have done, the alternative. We conducted two experiments to test whether the salience of the alternative contributes to how people derive implicatures. Participants responded true or false to underinformative categorical sentences that involved quantifiers. Target sentences were sometimes preceded by the alternative and sometimes by a control sentence. When the target was preceded by the alternative, response times to implicature responses were faster than when preceded by the control sentence. This suggests that (1) alternative salience influences higher-level reasoning (2) the cost of deriving implicatures in sentence verification paradigms is due in part to low alternative salience.

COVID-19 myth-busting: an experimental study.

BACKGROUND: COVID-19 misinformation is a danger to public health. A range of formats are used by health campaigns to correct beliefs but data on their effectiveness is limited. We aimed to identify A) whether three commonly used myth-busting formats are effective for correcting COVID-19 myths, immediately and after a delay, and B) which is the most effective. METHODS: We tested whether three common correction formats could reduce beliefs in COVID-19 myths: (i) question-answer, ii) fact-only, (ii) fact-myth. n = 2215 participants (n = 1291 after attrition), UK representative of age and gender, were randomly assigned to one of the three formats. n = 11 myths were acquired from fact-checker websites and piloted to ensure believability. Participants rated myth belief at baseline, were shown correction images (the intervention), and then rated myth beliefs immediately post-intervention and after a delay of at least 6 days. A partial replication, n = 2084 UK representative, was also completed with immediate myth rating only. Analysis used mixed models with participants and myths as random effects. RESULTS: Myth agreement ratings were significantly lower than baseline for all correction formats, both immediately and after the delay; all ß's > 0.30, p's < .001. Thus, all formats were effective at lowering beliefs in COVID-19 misinformation. Correction formats only differed where baseline myth agreement was high, with question-answer and fact-myth more effective than fact-only immediately; ß = 0.040, p = .022 (replication set: ß = 0.053, p = .0075) and ß = - 0.051, p = .0059 (replication set: ß = - 0.061, p < .001), respectively. After the delay however, question-answer was more effective than fact-myth, ß = 0.040, p =. 031. CONCLUSION: Our results imply that COVID-19 myths can be effectively corrected using materials and formats typical of health campaigns. Campaign designers can use our results to choose between correction formats. When myth belief was high, question-answer format was more effective than a fact-only format immediately post-intervention, and after delay, more effective than fact-myth format.

It is not always a matter of time: Addressing the costs of metaphor and metonymy through a speed-accuracy trade-off study.

One of the most debated topics in figurative language studies is whether the access to non-literal meanings is direct or indirect. Although models that argue for longer processing times for figurative compared to literal meanings have been largely criticized, figurative language is often associated with increased cognitive work. We investigated whether such greater cognitive work is indicative of more time-consuming processes or rather lower availability of figurative meanings, and whether there are differences between figurative types. We used a multi-response Speed-Accuracy Trade-off paradigm, where a meaningfulness judgment task was combined with a response deadline procedure to estimate speed and accuracy independently for metaphorical (Those dancers are butterflies) and metonymic sentences (That student reads Camilleri), compared with literal equivalents. While both metaphors and metonymies showed lower asymptote, that is, they were judged less accurately than literal counterparts, only metonymies were associated with a processing delay. Moreover, the difference in asymptote with respect to the literal condition was greater for metaphor than for metonymy. These findings indicate that the process that derives metaphor and metonymy is more complex than the process that derives literal meanings, even more so for metaphor. The processing delay, however, is present only in the case of metonymies. Taken together, our study offers key findings that reconcile a lively debate on the time course of figurative language comprehension, showing that the cost of non-literal meaning is not always a matter of time, and depends also on the figurative type. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The health benefits and cost-effectiveness of complete healthy vending.

Vending machines contribute to growing levels of obesity. They typically contain energy dense, high fat snacks and attempts at persuading consumers to switch to healthier snacks sold within the same machine have had limited success. This study explored the health benefits and cost effectiveness of the complete replacement of regular snacks with healthy items. Two vending machines were manipulated in a 6-month trial, with a healthy and regular range of products alternated between the two machines every fortnight. Healthy vending resulted in a 61% drop in calories sold relative to regular vending, significant with time and product range as random factors. There was no evidence of compensatory behaviour from nearby shop sales nor in multi-item purchases from vending machines. The impact on profit was less clear. Sales dropped by 30% during healthy vending but variability across product range meant that the change was not significant. Overall our results demonstrate that complete healthy vending can be introduced in hospitals without a catastrophic loss in sales nor compensatory behaviours that offset the public health gains of consuming healthier products.

Causal overstatements reduced in press releases following academic study of health news.

Background: Exaggerations in health news were previously found to strongly associate with similar exaggerations in press releases. Moreover such exaggerations did not appear to attract more news. Here we assess whether press release practice changed after these reported findings; simply drawing attention to the issue may be insufficient for practical change, given the challenges of media environments. Methods: We assessed whether rates of causal over-statement in press releases based on correlational data were lower following a widely publicised paper on the topic, compared to an equivalent baseline period in the preceding year. Results: We found that over-statements in press releases were 28% (95% confidence interval = 16% to 45%) in 2014 and 13% (95% confidence interval = 6% to 25%) in 2015. A corresponding numerical reduction in exaggerations in news was not significant. The association between over-statements in news and press releases remained strong. Conclusions: Press release over-statements were less frequent following publication of Sumner et al. (2014). However, this is correlational evidence and the reduction may be due to other factors or natural fluctuations.

Overlapping Mechanisms in Implying and Inferring.

Prior psychological work on Gricean implicature has revealed much about how listeners infer (comprehension) but little about how speakers imply (production). This is surprising given the inherent link between the two. This study aimed to obtain a more integral understanding of implicatures by investigating the processes that are shared between inference and implication. In two experiments, a participant and a confederate engaged in a dialogue game that invited the use of implicatures. In each there was a global priming manipulation, in which a confederate predominantly used implicit or explicit utterances, and a local priming manipulation, in which the utterance structure varied from trial to trial. Participants could choose whether to imply or use an explicit expression. Our results revealed that speaker and listener align on their use of implicatures. We interpret the local priming results as providing evidence of shared implicature representations between speaker and listener, and the global priming results as a form of audience design. We also present a model of implicature production that explains our findings.

The association between exaggeration in health-related science news and academic press releases: a replication study.

Background: Exaggerations in health news were previously found to strongly associate with similar exaggerations in press releases. Moreover, such press release exaggerations did not appear to attract more news. Methods: Here we tested the replicability of these findings in a new cohort of news and press releases based on research in UK universities in 2014 and 2015. Press releases and news were compared to their associated peer-reviewed articles to define exaggeration in advice, causal claims and human inference from non-human studies. Results: We found that the association between news and press releases did not replicate for advice exaggeration, while this association did replicate for causal claims and human inference from non-human studies. There was no evidence for higher news uptake for exaggerated press releases, consistent with previous results. Base exaggeration rates were lower for human inference from non-human studies, possibly reflecting the Concordat on Openness on Animal Research in the UK. Conclusions: Overall, the picture remains that the strength of news statements is normally associated with the strength of press release statements, and without evidence that exaggerated statements get significantly more news.

Event-related potentials in pragmatic priming.

Priming of pragmatic enrichment has been found in behavioural studies. We extend this by examining the neural correlates of priming for two implicature categories, quantifiers and disjunctions. Participants engaged in a primed sentence-picture matching task where they were presented with a sentence (e.g., "some of the letters are Bs") followed by a picture. In prime trials the pictures were either consistent with an enriched interpretation (some but not all) or a basic interpretation (some and possibly all) of the sentence. The pictures in target trials were always consistent with the enriched interpretation. Using ERPs, we found a priming effect on the picture reflected in a reduced positivity for quantifiers when the preceding trial had an enriched interpretation, and no effect for disjunction. The pragmatic priming effect can be dissociated from expectation-based processes. It suggests that abstract derivation processes are primed during pragmatic alignment.

Caveats in science-based news stories communicate caution without lowering interest.

Science stories in the media are strongly linked to changes in health-related behavior. Science writers (including journalists, press officers, and researchers) must therefore frame their stories to communicate scientific caution without disrupting coherence and disengaging the reader. In this study we investigate whether caveats ("Further research is needed to validate the results") satisfy this dual requirement. In four experiments participants read news reports with and without caveats. In Experiments 1 to 3, participants judged how cautious or confident researchers were, and how interesting or comprehensible they found the reports. News reports with caveats were judged as more cautious that those without, but levels of reader interest and comprehensibility were unaffected. In a fourth experiment, we created a mock newsroom and recruited journalism students to make judgments about which press releases should be published. Here, neither caveats nor the introduction of qualifying expressions in headlines had an effect on judgments of newsworthiness, consistent with Experiments 1 to 3. The reasons participants gave for rejecting a press release rarely referred to the caveat. Our results therefore suggest that science writers should include caveats in news reporting and that they can do so without fear of disengaging their readers or losing news uptake. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Claims of causality in health news: a randomised trial.

BACKGROUND: Misleading news claims can be detrimental to public health. We aimed to improve the alignment between causal claims and evidence, without losing news interest (counter to assumptions that news is not interested in communicating caution). METHODS: We tested two interventions in press releases, which are the main sources for science and health news: (a) aligning the headlines and main causal claims with the underlying evidence (strong for experimental, cautious for correlational) and (b) inserting explicit statements/caveats about inferring causality. The 'participants' were press releases on health-related topics (N = 312; control = 89, claim alignment = 64, causality statement = 79, both = 80) from nine press offices (journals, universities, funders). Outcomes were news content (headlines, causal claims, caveats) in English-language international and national media (newspapers, websites, broadcast; N = 2257), news uptake (% press releases gaining news coverage) and feasibility (% press releases implementing cautious statements). RESULTS: News headlines showed better alignment to evidence when press releases were aligned (intention-to-treat analysis (ITT) 56% vs 52%, OR = 1.2 to 1.9; as-treated analysis (AT) 60% vs 32%, OR = 1.3 to 4.4). News claims also followed press releases, significant only for AT (ITT 62% vs 60%, OR = 0.7 to 1.6; AT, 67% vs 39%, OR = 1.4 to 5.7). The same was true for causality statements/caveats (ITT 15% vs 10%, OR = 0.9 to 2.6; AT 20% vs 0%, OR 16 to 156). There was no evidence of lost news uptake for press releases with aligned headlines and claims (ITT 55% vs 55%, OR = 0.7 to 1.3, AT 58% vs 60%, OR = 0.7 to 1.7), or causality statements/caveats (ITT 53% vs 56%, OR = 0.8 to 1.0, AT 66% vs 52%, OR = 1.3 to 2.7). Feasibility was demonstrated by a spontaneous increase in cautious headlines, claims and caveats in press releases compared to the pre-trial period (OR = 1.01 to 2.6, 1.3 to 3.4, 1.1 to 26, respectively). CONCLUSIONS: News claims-even headlines-can become better aligned with evidence. Cautious claims and explicit caveats about correlational findings may penetrate into news without harming news interest. Findings from AT analysis are correlational and may not imply cause, although here the linking mechanism between press releases and news is known. ITT analysis was insensitive due to spontaneous adoption of interventions across conditions. TRIAL REGISTRATION: ISRCTN10492618 (20 August 2015).

The role of alternative salience in the derivation of scalar implicatures.

Comprehension can be enriched by considering what a speaker could have said but did not; namely, the alternative. For example, "Betty passed some of her exams" can be interpreted as "Betty passed some but not all of her exams". This enriched interpretation is an example of a scalar implicature. We consider whether the salience and use of the alternative are independent processes in the derivation of scalar implicatures or whether use is dependent on salience. Participants completed three sentence interpretation experiments in which the sentences invited scalar implicatures. The experiments used a structural priming paradigm with alternatives and implicatures as primes. We found that (1) adults could be primed to derive scalar implicatures when the alternative was the prime (2) they did so at a rate equal to if the scalar implicature itself were the prime. In the absence of evidence that the use of the alternative can be primed independently of its salience, we conclude that salience and use are not independent processes. Instead, we suggest that when the alternative is sufficiently salient, the implicature will automatically be derived.

Intonation and Pragmatic Enrichment: How Intonation Constrains Ad Hoc Scalar Inferences.

Pragmatic inferences require listeners to use alternatives to arrive at the speaker's intended meaning. Previous research has shown that intonation interacts with alternatives but not how it does so. We present two mouse tracking experiments that test how pitch accents affect the processing of ad hoc scalar implicatures in English. The first shows that L+H* accents facilitate implicatures relative to H* accents. The second replicates this finding and demonstrates that the facilitation is caused by early derivation of the implicature in the L+H* condition. We attribute the effect to a link between L+H* and pragmatic considerations, such as speaker knowledge effects, or the saliency of alternatives relevant to the computation of implicatures. More generally our findings illustrate how intonation interacts at a cognitive level with pragmatic inference.

Structural priming is a useful but imperfect technique for studying all linguistic representations, including those of pragmatics.

Structural priming is a useful tool for investigating linguistics representations. We argue that structural priming can be extended to the investigation of pragmatic representations such as Gricean enrichments. That is not to say priming is without its limitations, however. Interpreting a failure to observe priming may not be as simple as Branigan & Pickering (B&P) imply.

How readers understand causal and correlational expressions used in news headlines.

[Correction Notice: An Erratum for this article was reported in Vol 23(1) of Journal of Experimental Psychology: Applied (see record 2016-59631-001). In the article, the fourth author was inadvertently omitted from the advance online version. Also, the second paragraph of the author note should have included the following: "Amy Barrington contributed to the design and data collection for Experiments 2 and 3. We thank the following undergraduate students for contributions to Experiment 1 and pilot work leading up to the project: Laura Benjamin, Cecily Donnelly, Cameron Dunlop, Rebecca Emerson, Rose Fisher, Laura Jones, Olivia Manship, Hannah McCarthy, Naomi Scott, Eliza Walwyn-Jones, Leanne Whelan, and Joe Wilton." All versions of this article have been corrected.] Science-related news stories can have a profound impact on how the public make decisions. The current study presents 4 experiments that examine how participants understand scientific expressions used in news headlines. The expressions concerned causal and correlational relationships between variables (e.g., "being breast fed makes children behave better"). Participants rated or ranked headlines according to the extent that one variable caused the other. Our results suggest that participants differentiate between 3 distinct categories of relationship: direct cause statements (e.g., "makes," "increases"), which were interpreted as the most causal; can cause statements (e.g., "can make," "can increase"); and moderate cause statements (e.g., "might cause," "linked," "associated with"), but do not consistently distinguish within the last group despite the logical distinction between cause and association. On the basis of this evidence, we make recommendations for appropriately communicating cause and effect in news headlines. (PsycINFO Database Record

Exaggerations and Caveats in Press Releases and Health-Related Science News.

BACKGROUND: Exaggerated or simplistic news is often blamed for adversely influencing public health. However, recent findings suggested many exaggerations were already present in university press releases, which scientists approve. Surprisingly, these exaggerations were not associated with more news coverage. Here we test whether these two controversial results also arise in press releases from prominent science and medical journals. We then investigate the influence of mitigating caveats in press releases, to test assumptions that caveats harm news interest or are ignored. METHODS AND FINDINGS: Using quantitative content analysis, we analyzed press releases (N = 534) on biomedical and health-related science issued by leading peer-reviewed journals. We similarly analysed the associated peer-reviewed papers (N = 534) and news stories (N = 582). Main outcome measures were advice to readers and causal statements drawn from correlational research. Exaggerations in press releases predicted exaggerations in news (odds ratios 2.4 and 10.9, 95% CIs 1.3 to 4.5 and 3.9 to 30.1) but were not associated with increased news coverage, consistent with previous findings. Combining datasets from universities and journals (996 press releases, 1250 news), we found that when caveats appeared in press releases there was no reduction in journalistic uptake, but there was a clear increase in caveats in news (odds ratios 9.6 and 9.5 for caveats for advice and causal claims, CIs 4.1 to 24.3 and 6.0 to 15.2). The main study limitation is its retrospective correlational nature. CONCLUSIONS: For health and science news directly inspired by press releases, the main source of both exaggerations and caveats appears to be the press release itself. However we find no evidence that exaggerations increase, or caveats decrease, the likelihood of news coverage. These findings should be encouraging for press officers and scientists who wish to minimise exaggeration and include caveats in their press releases.

The time course of familiar metonymy.

Metonymic words have multiple related meanings, such as college, as in the building ("John walked into the college") or the educational institution ("John was promoted by the college"). Most researchers have found support for direct access models of metonymy but one recent study, Lowder and Gordon (2013), found delayed reading times for metonymic sentences relative to literal controls, in support of an indirect access account. We conducted a speed-accuracy-tradeoff experiment to test whether their result was caused by lower retrieval probabilities, consistent with direct or indirect access models of metonymy, or slower retrieval dynamics, consistent only with indirect access accounts. We found lower retrieval probabilities for the metonymic sentences but no difference in the dynamics parameters. These results therefore suggest that literal senses do not have priority during processing and that established metonymic senses can be accessed directly. (PsycINFO Database Record

Processing inferences at the semantics/pragmatics frontier: disjunctions and free choice.

Linguistic inferences have traditionally been studied and categorized in several categories, such as entailments, implicatures or presuppositions. This typology is mostly based on traditional linguistic means, such as introspective judgments about phrases occurring in different constructions, in different conversational contexts. More recently, the processing properties of these inferences have also been studied (see, e.g., recent work showing that scalar implicatures is a costly phenomenon). Our focus is on free choice permission, a phenomenon by which conjunctive inferences are unexpectedly added to disjunctive sentences. For instance, a sentence such as "Mary is allowed to eat an ice-cream or a cake" is normally understood as granting permission both for eating an ice-cream and for eating a cake. We provide data from four processing studies, which show that, contrary to arguments coming from the theoretical literature, free choice inferences are different from scalar implicatures.