Inhibitory control is one of several cognitive mechanisms required for self-regulation, decision making and attention towards tasks. Linked to a variety of maladaptive behaviours in humans, inhibitory control is expected to influence behavioural plasticity in animals in the context of foraging, social interaction, or responses to sudden changes in the environment. One widely used cognitive assay, the detour task, putatively tests inhibitory control. In this task, subjects must avoid impulsively touching transparent barriers positioned in front of food, and instead access the food by an alternative but known route. Recently it has been suggested that the detour task is unreliable and measures factors unrelated to inhibitory control, including motivation, previous experience and persistence. Consequently, there is growing uncertainty as to whether this task leads to erroneous interpretations about animal cognition and its links with socio-ecological traits. To address these outstanding concerns, we designed a variant of the detour task for wild great tits (Parus major) and deployed it at the nesting site of the same individuals across two spring seasons. This approach eliminated the use of food rewards, limited social confounds, and maximised motivation. We compared task performance in the wild with their performance in captivity when tested using the classical cylinder detour task during the non-breeding season. Task performance was temporally and contextually repeatable, and none of the confounds had any significant effect on performance, nor did they drive any of the observed repeatable differences among individuals. These results support the hypothesis that our assays captured intrinsic differences in inhibitory control. Instead of throwing the detour task out with the bathwater, we suggest confounds are likely system and experimental-design specific, and that assays for this potentially fundamental but largely overlooked source of behavioural plasticity in animal populations, should be validated and refined for each study system.

Conclusions These findings must be interpreted with caution because any word search is dependent on the use of language, which varies between countries and language groups, and over time. Also, the affiliation field refers only to the first author. With these caveats, this historical analysis supports some anecdotal impressions about occupational epidemiology: Nordic countries, relative to their size, have made a major contribution; historically, papers have come from a small pool of countries; the large volume of papers from the USA is likely to be influential; and the trend of accelerating research output seen in the twentieth century may have stabilised. Objectives To develop a framework for handling missing participant data for continuous outcomes in systematic reviews and assess its impact on risk of bias. Methods We conducted a consultative, iterative process. We considered sources that reflect real observed outcomes in participants followed-up in individual trials included in the systematic review, and developed a range of plausible strategies that would be progressively more stringent in challenging the robustness of the pooled estimates. We applied our approach to two example systematic reviews. Results We used 5 sources of data for imputing the means for participants with missing data: [A] the best mean score among the intervention arms of included trials, [B] the best mean score among the control arms of included trials, [C] the mean score from the control arm of the same trial, [D] the worst mean score among the intervention arms of included trials, [E] the worst mean score among the control arms of included trials. To impute SD, we used the median SD from the control arms of all included trials. Using these sources of data, we developed four progressively more stringent imputation strategies. 181In the first example review, effect estimates were diminished and lost significance as the strategies became more stringent, suggesting the need to rate down confidence in estimates of effect for risk of bias. In the second review, effect estimates maintained statistical significance using even the most stringent strategy, suggesting missing data does not undermine confidence in the results. The differences are due to: [1] the size of the effect and its precision, and [2] the percentage of missing participant data. Conclusions Our approach provides rigorous yet reasonable and relatively simple, quantitative guidance for judging the impact of risk of bias as a result of missing participant data in systematic reviews of continuous outcomes. Objective To assess whether English-speaking reviewers can identify foreign-language articles that are eligible for a systematic review of all treatments for fibromyalgia. Methods Systematic review of AMED, CINAHL, EMBASE, MEDLINE, HealthSTAR, PsycINFO, Papers First, Proceedings First and CENTRAL, from inception of each database to April, 2011, to identify all randomised controlled trials exploring any form of therapy for fibromyalgia. All non-English language articles were...