Underpowered samples, false negatives, and unconscious learning

The scientific community has witnessed growing concern about the high rate of false positives and unreliable results within the psychological literature, but the harmful impact of false negatives has been largely ignored. False negatives are particularly concerning in research areas where demonstrating the absence of an effect is crucial, such as studies of unconscious or implicit processing. Research on implicit processes seeks evidence of above-chance performance on some implicit behavioral measure at the same time as chance-level performance (that is, a null result) on an explicit measure of awareness. A systematic review of 73 studies of contextual cuing, a popular implicit learning paradigm, involving 181 statistical analyses of awareness tests, reveals how underpowered studies can lead to failure to reject a false null hypothesis. Among the studies that reported sufficient information, the meta-analytic effect size across awareness tests was d z = 0.31 (95 % CI 0.24–0.37), showing that participants’ learning in these experiments was conscious. The unusually large number of positive results in this literature cannot be explained by selective publication. Instead, our analyses demonstrate that these tests are typically insensitive and underpowered to detect medium to small, but true, effects in awareness tests. These findings challenge a widespread and theoretically important claim about the extent of unconscious human cognition

A comparator-hypothesis account of biased contingency detection.

Our ability to detect statistical dependencies between different events in the environment is strongly biased by the number of coincidences between them. Even when there is no true covariation between a cue and an outcome, if the marginal probability of either of them is high, people tend to perceive some degree of statistical contingency between both events. The present paper explores the ability of the Comparator Hypothesis to explain the general pattern of results observed in this literature. Our simulations show that this model can account for the biasing effects of the marginal probabilities of cues and outcomes. Furthermore, the overall fit of the Comparator Hypothesis to a sample of experimental conditions from previous studies is comparable to that of the popular Rescorla-Wagner model. These results should encourage researchers to further explore and put to the test the predictions of the Comparator Hypothesis in the domain of biased contingency detection

An attempt to correct erroneous ideas among teacher education students: The effectiveness of refutation texts

There is sound evidence about the high prevalence of misconceptions about education among pre-service teachers. This trend continues after students complete the degree in education and once they are in the exercise of their profession. In fact, several studies show that these misconceptions are widespread among in-service teachers. Erroneous ideas about education may divert material and human resources to poor grounded methods and teaching tools, compromising the quality of education. Strategies to debunk misconceptions among future teachers, who may not have a firm position about many educational issues, might contribute to reversing this trend. The main goal of the present study was to assess the efficacy of refutation texts in the correction of misconceptions among pre-service teachers. As in previous studies with in-service teachers, refutation texts were effective in reducing participants’ endorsement of misconceptions. But this effect was short-lived and did not affect participants’ intention to use educational methods that are based on the misconceptions addressed in the refutation textsMF was supported by grant AYD-000-235 from bizkaia:talent, Diputación Foral de Bizkaia, and by a postdoctoral grant from Programa Posdoctoral de Perfeccionamiento de Personal Investigador Doctor, Gobierno Vasco. MV was supported by grants PSI2017-85159-P (AEI / FEDER, UE) and 2016-T1/SOC- 1395 (Comunidad de Madrid, Programa de Atracción de Talento Investigador)

Persistence of Causal Illusions After Extensive Training

We carried out an experiment using a conventional causal learning task but extending the number of learning trials participants were exposed to. Participants in the standard training group were exposed to 48 learning trials before being asked about the potential causal relationship under examination, whereas for participants in the long training group the length of training was extended to 288 trials. In both groups, the event acting as the potential cause had zero correlation with the occurrence of the outcome, but both the outcome density and the cause density were high, therefore providing a breeding ground for the emergence of a causal illusion. In contradiction to the predictions of associative models such the Rescorla-Wagner model, we found moderate evidence against the hypothesis that extending the learning phase alters the causal illusion. However, assessing causal impressions recurrently did weaken participants' causal illusions

The evidential value of research on cognitive training to change food-related biases and unhealthy eating behavior: A systematic review and p-curve analysis

Cognitive bias modification (CBM), which retrains implicit biases towards unhealthy foods, has been proposed as a promising adjunct to improve the efficacy of weight loss interventions. We conducted a systematic review of research on three CBM approaches (i.e., cue-specific inhibitory control, approach bias modification, and attentional bias modification) for reducing unhealthy eating biases and behavior. We performed a p-curve analysis to determine the evidential value of this research; this method is optimally suited to clarify whether published results reflect true effects or false positives due to publication and reporting biases. When considering all CBM approaches, our results suggested that the findings of CBM trials targeting unhealthy eating are unlikely to be false positives. However, only research on attentional bias modification reached acceptable levels of power. These results suggest that CBM interventions may be an effective strategy to enhance the efficacy of weight loss interventions. However, there is room for improvement in the methodological standards of this area of research, especially increasing the statistical power can help to fully clarify the clinical potential of CBM, and determine the role of potential moderatorsConsejería de Educación e Investigación, Grant/Award Numbers: 2016-T1/SOC-1395, 2020-5A/SOC-19723; Spanish Ministry of Science and Innovation, Grant/Award Numbers: PSI2017-85159-P, Ref. FJC2018-036047-

Is project-based learning effective among kindergarten and elementary students? A systematic review

Project-based learning (PjBL) is becoming widespread in many schools. However, the evidence of its effectiveness in the classroom is still limited, especially in basic education. The aim of the present study was to perform a systematic review of the empirical evidence assessing the impact of PjBL on academic achievement of kindergarten and elementary students. We also examined the quality of studies, their compliance with basic prerequisites for a successful result, and their fidelity towards the key elements of PBL intervention. For this objective, we conducted a literature search in January 2020. The inclusion criteria for the review required that studies followed a pre-post design with control group and measured quantitatively the impact of PBL on content knowledge of students. The final sample included eleven articles comprising data from 722 students. The studies yielded inconclusive results, had important methodological flaws, and reported insufficient or no information about important aspects of the materials, procedure and key requirements from students and instructors to guarantee the success of PjBL. Educational implications of these results are discussed

Are we truly special and unique? A replication of Goldenberg et al. (2001)

According to the mortality salience hypothesis of terror management theory, reminders of our future death increase the necessity to validate our cultural worldview and to enhance our self-esteem. In Experiment 2 of the study 'I am not an animal: Mortality salience, disgust, and the denial of human creatureliness', Goldenberg et al. (Goldenberg et al. 2001 J. Exp. Psychol. Gen. 130, 427-435. (doi:10.1037/0096-3445.130.3.427)) observed that participants primed with questions about their death provided more positive evaluations to an essay describing humans as distinct from animals than control participants presented with questions regarding another aversive situation. In a replication of this experiment conducted with 128 volunteers, we did not observe evidence for a mortality salience effect

Is probabilistic cuing of visual search an inflexible attentional habit? A meta-analytic review

In studies on probabilistic cuing of visual search, participants search for a target among several distractors and report some feature of the target. In a biased stage the target appears more frequently in one specific area of the search display. Eventually, participants become faster at finding the target in that rich region compared to the sparse region. In some experiments, this stage is followed by an unbiased stage, where the target is evenly located across all regions of the display. Despite this change in the spatial distribution of targets, search speed usually remains faster when the target is located in the previously rich region. The persistence of the bias even when it is no longer advantageous has been taken as evidence that this phenomenon is an attentional habit. The aim of this meta-analysis was to test whether the magnitude of probabilistic cuing decreases from the biased to the unbiased stage. A meta-analysis of 42 studies confirmed that probabilistic cuing during the unbiased stage was roughly half the size of cuing during the biased stage, and this decrease persisted even after correcting for publication bias. Thus, the evidence supporting the claim that probabilistic cuing is an attentional habit might not be as compelling as previously thoughtOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was supported by grants 2016-T1/SOC-1395, 2017-T1/SOC-5147, and 2020-5A/SOC-19723 from Comunidad de Madrid, Spain (Programa de Atracción de Talento Investigador), grants PSI2017-85159-P, PGC2018-094694-B-I00, and PID2020-118583GB-I00 from Agencia Estatal de Investigación, Spain, and FEDER, EU, and grant ES/S014616/1 from the Economic and Social Research Council, United Kingdo

Learning to suppress a distractor may not be unconscious

The additional singleton task has become a popular paradigm to explore visual statistical learning and selective attention. In this task, participants are instructed to find a different-shaped target among a series of distractors as fast as possible. In some trials, the search display includes a singleton distractor with a different color, making search more difficult. This singleton distractor appears more often in one location than in the remaining locations. The typical results of these experiments show that participants learn to ignore the area of the screen that is more likely to contain the singleton distractor. It is often claimed that this learning takes place unconsciously, because at the end of the experiment participants seem to be unable to identify the location where the singleton distractor appeared most frequently during the task. In the present study, we tested participants’ awareness in three high-powered experiments using alternative measures. Contrary to previous studies, the results show clear evidence of explicit knowledge about which area of the display was more likely to contain the singleton distractor, suggesting that this type of learning might not be unconsciousOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was supported by grants 2016-T1/SOC-1395 (MAV, TGF), and 2017-T1/SOC-5147 (DL, TGF) and 2020-5A/SOC-19723 (MAV) from Comunidad de Madrid (Programa de Atracción de Talento Investigador) and by grants PSI2017-85159-P (MAV, FVC), PGC2018-094694-B-I00 (DL) and PID2020-118583GB-I00 (MAV, TGF, FVC) from Agencia Estatal de Investigación and FEDER, UE. FVC was supported by PhD fellowship PRE2018-085148 from Ministerio de Ciencia e Innovació

Are we truly special and unique? A replication of Goldenberg et al. (2001)

According to the mortality salience hypothesis of terror management theory, reminders of our future death increase the necessity to validate our cultural worldview and to enhance our self-esteem. In Experiment 2 of the study ‘I am not an animal: Mortality salience, disgust, and the denial of human creatureliness’, Goldenberg et al. (Goldenberg et al. 2001 J. Exp. Psychol. Gen. 130, 427–435. (doi:10.1037/0096-3445.130.3.427)) observed that participants primed with questions about their death provided more positive evaluations to an essay describing humans as distinct from animals than control participants presented with questions regarding another aversive situation. In a replication of this experiment conducted with 128 volunteers, we did not observe evidence for a mortality salience effect.J.R.-F., I.B. and M.A.V. were supported by grant nos. PSI2016-80061-R (AEI/FEDER UE), PSI2016-75776-R (AEI/FEDER UE) and PSI2017-85159-P (AEI/FEDER UE), respectively. M.A.V. was also supported by grant no. 2016-T1/SOC-1395 (Comunidad de Madrid; Programa de Atracción de Talento Investigador)