How varying cue duration influences item-method directed forgetting: A novel selective retrieval interpretation.

A series of four experiments tested the assumptions of the most prominent and longstanding account of item-method directed forgetting: the selective rehearsal account. In the item-method directed forgetting paradigm, each presented item is followed by its own instructional cue during the study phase - either to-be-forgotten (F) or to-be-remembered (R). On a subsequent test, memory is poorer for F items than for R items. To clarify the mechanism underlying memory performance, we manipulated the time available for rehearsal, examining instructional cue durations of 1 s, 5 s, and 10 s. Experiments 1a and 1b, where the order of cue durations was randomized, showed no effect of cue duration on item recognition of unrelated single words, for either R or F items. Experiment 2, using unrelated word pairs, again showed no effect of randomized cue duration, this time on associative recognition. Experiments 3 and 4 blocked cue duration and showed equivalent increases in recognition of both R and F single words and word pairs with increasing cue duration. We suggest that any post-cue rehearsal is carried out only when cue duration is predictable, and that such limited rehearsal is equally likely for F items and R items. The consistently better memory for R items than for F items across cue duration depends on selective retrieval involving (1) a rapid retrieval check engaged for R items only and (2) a rapid removal process implemented for F items only.

Reading text aloud benefits memory but not comprehension.

The production effect-that reading aloud leads to better memory than does reading silently-has been defined narrowly with reference to memory; it has been explored largely using word lists as the material to be read and remembered. But might the benefit of production extend beyond memory and beyond individual words? In a series of four experiments, passages from reading comprehension tests served as the study material. Participants read some passages aloud and others silently. After each passage, they completed multiple-choice questions about that passage. Separating the multiple-choice questions into memory-focused versus comprehension-focused questions, we observed a consistent production benefit only for the memory-focused questions. Production clearly improves memory for text, not just for individual words, and also extends to multiple-choice testing. The overall pattern of findings fits with the distinctiveness account of production-that information read aloud stands out at study and at test from information read silently. Only when the tested information is a very close match to the studied information, as is the case for memory questions but not for comprehension questions, does production improve accuracy.

Serotonin and emotion regulation: the impact of tryptophan depletion on emotional experience, neural and autonomic activity.

The involvement of serotonin in emotion and psychopathology has been extensively examined. Studies using acute tryptophan depletion (ATD) have found limited effects on mood and aggression, and one of the explanations suggests that serotonin may be involved in higher-order functions, such as emotion regulation. However, there is very limited evidence for this hypothesis. The present study investigated the impact of ATD on emotion regulation in a double-blind, placebo-controlled, crossover design. A sample of psychiatrically healthy men (N = 28) completed a cognitive task assessing reappraisal ability (i.e., the success of using reappraisal, an emotion regulation strategy, to modulate emotional responses), following ATD and placebo. EEG frontal activity and asymmetry, as well as heart-rate variability (HRV), also were assessed in the reappraisal task. Both frequentist and Bayesian methods were employed for statistical analysis. Results indicated that ATD reduced plasma tryptophan, and reappraisal was effective in modulating emotional experience in the emotion regulation task. However, ATD had no significant effect on reappraisal ability, frontal activity, and HRV. These results offer direct and compelling evidence that decreasing serotonin synthesis through ATD does not alter an emotion regulation ability that is considered crucial in mood and aggression and has been linked with transdiagnostic risk of psychopathology.

Variation in Clinical Characteristics and Longitudinal Outcomes in Individuals with Opioid Use Disorder Diagnosis Codes.

BACKGROUND: Patterns of opioid use vary, including prescribed use without aberrancy, limited aberrant use, and potential opioid use disorder (OUD). In clinical practice, similar opioid-related International Classification of Disease (ICD) codes are applied across this spectrum, limiting understanding of how groups vary by sociodemographic factors, comorbidities, and long-term risks. OBJECTIVE: (1) Examine how Veterans assigned opioid abuse/dependence ICD codes vary at diagnosis and with respect to long-term risks. (2) Determine whether those with limited aberrant use share more similarities to likely OUD vs those using opioids as prescribed. DESIGN: Longitudinal observational cohort study. PARTICIPANTS: National sample of Veterans categorized as having (1) likely OUD, (2) limited aberrant opioid use, or (3) prescribed, non-aberrant use based upon enhanced medical chart review. MAIN MEASURES: Comparison of sociodemographic and clinical factors at diagnosis and rates of age-adjusted mortality, non-fatal opioid overdose, and hospitalization after diagnosis. An exploratory machine learning analysis investigated how closely those with limited aberrant use resembled those with likely OUD. KEY RESULTS: Veterans (n = 483) were categorized as likely OUD (62.1%), limited aberrant use (17.8%), and prescribed, non-aberrant use (20.1%). Age, proportion experiencing homelessness, chronic pain, anxiety disorders, and non-opioid substance use disorders differed by group. All-cause mortality was high (44.2 per 1000 person-years (95% CI 33.9, 56.7)). Hospitalization rates per 1000 person-years were highest in the likely OUD group (831.5 (95% CI 771.0, 895.5)), compared to limited aberrant use (739.8 (95% CI 637.1, 854.4)) and prescribed, non-aberrant use (411.9 (95% CI 342.6, 490.4). The exploratory analysis reclassified 29.1% of those with limited aberrant use as having likely OUD with high confidence. CONCLUSIONS: Veterans assigned opioid abuse/dependence ICD codes are heterogeneous and face variable long-term risks. Limited aberrant use confers increased risk compared to no aberrant use, and some may already have OUD. Findings warrant future investigation of this understudied population.

Stable isotopes unravel the feeding mode-trophic position relationship in trematode parasites.

Stable isotopes have been sporadically used over the last two decades to characterise host-parasite trophic relationships. The main reason for this scarcity is the lack of an obvious pattern in the ratio of nitrogen stable isotope values (δ15 N) of parasites in comparison to their host tissues, which would be key to understand any host-parasite system dynamics. To circumvent this, we focused on a single snail host, Zeacumantus subcarinatus, and three of its trematode parasites. We used stable isotopes to investigate each host-trematode trophic relationship and shed light on the mechanisms utilised by the parasite to reroute its hosts' biomass. All our trematodes were found to be 15 N-enriched compared to their host, with their δ15 N values strongly related to their feeding behaviours: passive versus active. It was possible to 'rank' these parasite species and assess their 'relative' trophic position using δ15 N values. We also demonstrated that including a broader range of samples (e.g. host food and faeces, multiple parasite life stages) helped understand the metabolic mechanisms used by the various participants, and that using carbon stable isotope values and C:N ratios allowed to identify an important lipid requirement of these trematode parasites. Finally, we show how critical it is to not ignore parasitic infections as they can have a great influence on their host's trophic position. We have shown that by focussing on a single host species and a single taxonomic group of parasites, we can remove a certain amount of variation recorded by broader isotope studies. We hope that these data will ultimately improve our ability to place parasites in food webs, and thus improve our understanding of the connections and interactions that dictate food web dynamics.

The journey of hull-fouling mobile invaders: basibionts and boldness mediate dislodgement risk during transit.

Vessel hull-fouling is responsible for most bioinvasion events in the marine environment, yet it lacks regulation in most countries. Although experts advocate a preventative approach, research efforts on pre-arrival processes are limited. The performance of mobile epifauna during vessel transport was evaluated via laboratory simulations, using the well-known invasive Japanese skeleton shrimp (Caprella mutica), and its native congener C. laeviuscula as case study. The invader did not possess any advantage in terms of inherent resistance to drag. Instead, its performance was conditioned by the complexity of secondary substrate. Dislodgement risk was significantly reduced when sessile fouling basibionts were added, which provided refugia and boosted the probability of C. mutica remaining attached from 7 to 65% in flow exposure trials. Interestingly, the invader exhibited significantly higher exploratory tendency and motility than its native congener at zero-flow conditions. Implications in terms of en-route survivorship, invasion success and macrofouling management are discussed.

Emotional mental imagery generation during spontaneous future thinking: relationship with optimism and negative mood.

Optimism is known to buffer against negative mood. Thus, understanding the factors that contribute to individual variation in optimism may inform interventions for mood disorders. Preliminary evidence suggests that the generation of mental imagery-based representations of positive relative to negative future scenarios is related to optimism. This study investigated the hypothesis that an elevated tendency to generate positive relative to negative mental imagery during spontaneous future thinking would be associated with reduced negative mood via its relationship to higher optimism. Participants (N = 44) with varied levels of naturally occurring negative mood reported current levels of optimism and the real-time occurrence and characteristics of spontaneous thoughts during a sustained attention computer task. Consistent with hypotheses, higher optimism statistically mediated the relationship between a higher proportional frequency of positive relative to negative mental imagery during spontaneous future thinking and lower negative mood. Further, the relationship between emotional mental imagery and optimism was found for future, but not past, thinking, nor for verbal future or past thinking. Thus, a greater tendency to generate positive rather than negative imagery-based mental representations when spontaneously thinking about the future may influence how optimistic one feels, which in turn may influence one's experience of negative mood.

Attentional Bias to Alcohol Information: a Novel Dual-Probe Task.

BACKGROUND: Even when motivated to consume less alcohol, attempts to do so are not always successful. Attentional bias to positive and negative alcohol-related information may play a role in shaping unintended drinking behaviour. The present exploratory study adapted a novel attentional bias task, to test whether selective attention to positive relative to negative information about alcohol consumption predicts mismatch between alcohol consumption intention and alcohol consumption behaviour. METHOD: Thirty-five university students attempting to reduce their alcohol consumption participated in the study. Participants completed a novel attentional bias assessment task where two positive and negative audio-visual messages about alcohol consumption were simultaneously presented. At random intervals during these messages, two different probes were briefly and simultaneously presented, so that only one could be detected. Attention to positive vs. negative messages was inferred from the location of the probe recorded by the participant. Alcohol consumption in relation to participants' goals was measured using a real-time diary over the subsequent 7 days. RESULTS: An attentional bias towards positive (relative to negative) messages about alcohol consumption predicted the degree to which participants consumed more alcohol than planned, but did not predict alcohol consumption itself. CONCLUSION: This is the first study to our knowledge that has investigated the relationship between biased attention to alcohol-related information and variation in the success of intended reduction in alcohol consumption, and we suggest that it paves the way for further research into the role of attentional biases in health risk behaviours.

Healthiness matters: Approach motivation for healthy food in overweight and obese individuals.

It is well documented that approach tendencies for appetitive substances play a role in certain unhealthy patterns of consumption. However, it remains uncertain whether overweight individuals differ from healthy-weight individuals in terms of their tendency to approach unhealthy foods. Thus, the present study aimed to empirically test the hypothesis that overweight individuals are characterised by an elevated behavioural tendency to approach unhealthy food, rather than healthy food, as compared to healthy-weight individuals. Participants were forty-one overweight individuals (Mean BMI = 30.40 kg/m2) and forty-five healthy-weight individuals (Mean BMI = 22.17 kg/m2) aged between 17 and 47. They completed an Approach-Avoidance Task to assess behavioural approach-avoidance tendencies towards healthy and unhealthy food. Contrary to the hypothesis under test, results revealed a greater approach tendency towards healthy food in overweight individuals, as compared to healthy-weight individuals, whereas there were no group differences in behavioural approach-avoidance tendencies towards unhealthy food. These novel findings suggest that overweight individuals are characterised by an approach motivation for healthy food. We provide suggestions concerning how future researchers can build on these findings to test whether this approach tendency contributes to consumption behaviour in overweight individuals.

Enhanced capacity to switch but not to maintain: The basis of attentional bias to high calorie foods in restrained eaters.

It has been argued that high restrained eaters (i.e., people who fluctuate between restrictive food intake and overeating) are characterised by a heightened attentional bias to high calorie foods. However, the validity of this hypothesis has not yet been convincingly established. The current study sought to empirically evaluate this hypothesis using two directional measures of attentional bias: the well-established dot probe bias assessment task and the more novel Chase the Food bias assessment task. The latter attentional assessment approach has the capacity to differentiate between attentional switching and attentional maintenance within a complex and dynamic food environment. Participants (61 high restrained eaters and 38 low restrained eaters) completed the dot probe task and the Chase the Food task. Findings obtained on the dot probe task did not reveal a group difference in terms of biased attentional responding towards high calorie vs. low calorie food. Conversely, the two groups were found to differ on one of the measures obtained on the Chase the Food task. Specifically, high restrained eaters, as compared to low restrained eaters, demonstrated speeded attentional switching to high calorie foods, rather than a greater ability to maintain attention on high calorie foods when required to do so. These novel findings imply that high restrained eaters are potentially characterised by facilitated attentional switching towards high calorie foods. Implications are discussed including the possibility of targeting biased attentional switching using training variants of the Chase the Food task in interventions designed to reduce maladaptive eating behaviours.

The production effect is consistent over material variations: support for the distinctiveness account.

The production effect is the superior memory for items read aloud as opposed to silently at the time of study. The distinctiveness account holds that produced items benefit from the encoding of additional elements associated with the act of production. If so, then that benefit should be consistent regardless of item type. Three experiments, using three different sets of materials and three different methods, tested this hypothesis. Experiment 1, using recognition testing, showed consistent production benefits for high and low frequency words. Experiment 2, using free recall, showed consistent production increments for pictures and words. Experiment 3, using incidental learning, showed consistent production benefits for recognition of nonwords and words. Taken together, these results fit with the distinctiveness account: Production at encoding dependably adds information to the memory record, regardless of item type or method of testing, producing a consistently reliable memory benefit.

Trachoma, Anti-Pgp3 Serology, and Ocular Chlamydia trachomatis Infection in Papua New Guinea.

BACKGROUND: In Melanesia, the prevalence of trachomatous inflammation-follicular (TF) suggests that public health-level interventions against active trachoma are needed. However, the prevalence of trachomatous trichiasis is below the threshold for elimination as a public health problem and evidence of conjunctival infection with trachoma's causative organism (Chlamydia trachomatis [CT]) is rare. Here, we examine the prevalence of ocular infection with CT and previous exposure to CT in three evaluation units (EUs) of Papua New Guinea. METHODS: All individuals aged 1-9 years who were examined for clinical signs of trachoma in 3 Global Trachoma Mapping Project EUs were eligible to take part in this study (N = 3181). Conjunctival swabs were collected from 349 children with TF and tested by polymerase chain reaction to assess for ocular CT infection. Dried blood spots were collected from 2572 children and tested for anti-Pgp3 antibodies using a multiplex assay. RESULTS: The proportion of children with TF who had CT infection was low across all 3 EUs (overall 2%). Anti-Pgp3 seroprevalence was 5.2% overall and there was no association between anti-Pgp3 antibody level and presence of TF. In 2 EUs, age-specific seroprevalence did not increase significantly with increasing age in the 1- to 9-year-old population. In the third EU, there was a statistically significant change with age but the overall seroprevalence and peak age-specific seroprevalence was very low. CONCLUSIONS: Based on these results, together with similar findings from the Solomon Islands and Vanuatu, the use of TF to guide antibiotic mass drug administration decisions in Melanesia should be reviewed.

Recallable but not recognizable: The influence of semantic priming in recall paradigms.

When people can successfully recall a studied word, they should be able to recognize it as having been studied. In cued-recall paradigms, however, participants sometimes correctly recall words in the presence of strong semantic cues but then fail to recognize those words as actually having been studied. Although the conditions necessary to produce this unusual effect are known, the underlying neural correlates have not been investigated. Across five experiments, involving both behavioral and electrophysiological methods (EEG), we investigated the cognitive and neural processes that underlie recognition failures. Experiments 1 and 2 showed behaviorally that assuming that recalled items can be recognized in cued-recall paradigms is a flawed assumption, because recognition failures occur in the presence of cues, regardless of whether those failures are measured. With event-related potentials (ERPs), Experiments 3 and 4 revealed that successfully recalled words that are recognized are driven by recollection at recall and then by a combination of recollection and familiarity at ensuing recognition. In contrast, recognition failures did not show that memory signature and may instead be driven by semantic priming at recall and followed at recognition stages by negative-going ERP effects consistent with implicit processes, such as repetition fluency. These results demonstrate that recall - long-characterized as predominantly reflecting recollection-based processing in episodic memory - may at times also be served by a confluence of implicit cognitive processes.

Memory & Cognition: The first 40 years.

This article presents a survey of the first 40 years of this journal, covering (1) the origin and subsequent history of the journal, (2) who the editors have been, (3) the influence of the journal and its editors on the field, and (4) the most frequently cited articles. A virtually immediate success, Memory & Cognition has gone on to become one of the leading journals in the field of cognitive psychology.

Production between and within: distinctiveness and the relative magnitude of the production effect.

The production effect is the memory advantage for items studied aloud over items studied silently. Three experiments examined the influence of (1) the distinctiveness heuristic in a pure-list paradigm and (2) statistical distinctiveness during study. Aloud versus silent processing was manipulated within-subject in a mixed-list procedure and additional pure-list items were alternated with the to-be-remembered words. This arrangement permitted the first examination of the production effect using both within-subject and between-subjects manipulations in the same experiment. The quite large between-subjects production effect observed for the pure-list words is attributed to the distinctiveness of the aloud words being enhanced by the co-occurring within-subject manipulation. In addition, when the pure-list words were all read aloud, they effectively increased the overall proportion of aloud words, thereby decreasing the distinctiveness of the to-be-remembered aloud words in the mixed list. Correspondingly, there was a decrease in the magnitude of the production effect. However, when the pure-list words were all read silently, the magnitude of the production effect was unchanged relative to baseline. These results provide partial support for the influence of statistical distinctiveness on the magnitude of the production effect.

Attentional control moderates the relationship between social anxiety and selective attentional responding to negative social information: evidence from objective measures of attentional processes.

Cognitive theories of social anxiety implicate greater attention to negative social information in the development and maintenance of heightened social anxiety. Empirical evidence for this proposal, however, has been inconsistent. The aim of the current study was to examine the role of attentional control, which is one's ability to deploy attention to goal-relevant information as a potential moderator of the association between selective attentional responding to negative social information and social anxiety. Eighty-nine adults were recruited through Mechanical Turk platform and completed the Social Interaction Anxiety Scale as well as a novel paradigm designed to measure selective attentional responding to negative social information (angry faces) and attentional control. Attentional control was operationalised as the capacity to direct attention to the specified target stimuli. The results supported the hypothesis that attentional control plays this moderating role. Specifically, while participants with low levels of attentional control exhibited a positive association between social anxiety and selective attentional responding to negative social information, this association was eliminated among participants with high levels of attentional control. This finding may explain the heterogeneity of research findings in this area. Implications, limitations and directions for future research are discussed.

Estimating the Intracluster Correlation Coefficient for the Clinical Sign "Trachomatous Inflammation-Follicular" in Population-Based Trachoma Prevalence Surveys: Results From a Meta-Regression Analysis of 261 Standardized Preintervention Surveys Carried Out in Ethiopia, Mozambique, and Nigeria.

Sample sizes in cluster surveys must be greater than those in surveys using simple random sampling in order to obtain similarly precise prevalence estimates, because results from subjects examined in the same cluster cannot be assumed to be independent. Therefore, a crucial aspect of cluster sampling is estimation of the intracluster correlation coefficient (ρ): the degree of relatedness of outcomes in a given cluster, defined as the proportion of total variance accounted for by between-cluster variation. In infectious disease epidemiology, this coefficient is related to transmission patterns and the natural history of infection; its value also depends on particulars of survey design. Estimation of ρ is often difficult due to the lack of comparable survey data with which to calculate summary estimates. Here we use a parametric bootstrap model to estimate ρ for the ocular clinical sign "trachomatous inflammation-follicular" (TF) among children aged 1-9 years within population-based trachoma prevalence surveys. We present results from a meta-regression analysis of data from 261 such surveys completed using standardized methods in Ethiopia, Mozambique, and Nigeria in 2012-2015. Consistent with the underlying theory, we found that ρ increased with increasing overall TF prevalence and smaller numbers of children examined per cluster. Estimates of ρ for TF were independently higher in Ethiopia than in the other countries.

Causal underpinnings of working memory and Stroop interference control: Testing the effects of anodal and cathodal tDCS over the left DLPFC.

By means of transcranial direct current stimulation applied to the left dorsolateral prefrontal cortex, we investigated the causal role of increased or decreased excitability of this brain region for two facets of executive functions: working memory and Stroop interference control. We tested 1) whether anodal tDCS of the left DLPFC enhances working memory 15 minutes after termination of stimulation and in the absence of direct task practice under stimulation; 2) whether anodal tDCS of the left DLPFC enhances interference control, as evidenced by Stroop performance and Stroop sequence effects; and 3) whether cathodal tDCS leads to compromised executive functioning compared to anodal stimulation. In a between-subject design with 88 healthy psychology students, we compared the impact of anodal and cathodal stimulation against a sham condition, on performance on a Stroop task (during active stimulation) and on an n-back task (completed 15 minutes after active stimulation ended). We found significantly enhanced accuracy in the n-back task after anodal stimulation compared with sham, as well as speeded reactions in the Stroop tasks independent of trial type. By contrast, we found no modulation of Stroop interference effects or Stroop sequence effects. No inhibitory effects of cathodal stimulation were observed. These results support the causal role of the left DLPFC in working memory but lend no support to its involvement in Stroop interference control.

Cognitive bias modification to prevent depression (COPE): results of a randomised controlled trial.

BACKGROUND: Although efficacious treatments for major depression are available, efficacy is suboptimal and recurrence is common. Effective preventive strategies could reduce disability associated with the disorder, but current options are limited. Cognitive bias modification (CBM) is a novel and safe intervention that attenuates biases associated with depression. This study investigated whether the delivery of a CBM programme designed to attenuate negative cognitive biases over a period of 1 year would decrease the incidence of major depression among adults with subthreshold symptoms of depression. METHODS: Randomised double-blind controlled trial delivered an active CBM intervention or a control intervention over 52 weeks. Two hundred and two community-dwelling adults who reported subthreshold levels of depression were randomised (100 intervention, 102 control). The primary outcome of interest was the incidence of major depressive episode assessed at 11, 27 and 52 weeks. Secondary outcomes included onset of clinically significant symptoms of depression, change in severity of depression symptoms and change in cognitive biases. RESULTS: Adherence to the interventions was modest though did not differ between conditions. Incidence of major depressive episodes was low. Conditions did not differ in the incidence of major depressive episodes. Likewise, conditions did not differ in the incidence of clinically significant levels of depression, change in the severity of depression symptoms or change in cognitive biases. CONCLUSIONS: Active CBM intervention did not decrease the incidence of major depressive episodes as compared to a control intervention. However, adherence to the intervention programme was modest and the programme failed to modify the expected mechanism of action.

The Production Effect Improves Memory in 7- to 10-Year-Old Children.

The production effect-whereby reading words aloud improves memory for those words relative to reading them silently-was investigated in two experiments with 7- to 10-year-old children residing in Brisbane, Australia. Experiment 1 (n = 41) involved familiar printed words, with words read aloud or silently appearing either in mixed- or blocked-list formats in a within-subject design. Recognition for words read aloud was better than for those read silently, an effect consistent across both list formats. These results were confirmed in Experiment 2 (n = 40) using longer lists of printed novel nonwords. Final analyses indicated that the production effect was comparable for words and nonwords. Findings are discussed in relation to the distinctiveness account and the use of production as a mnemonic in children.