A large-scale study and six-month follow-up of an intervention to reduce causal illusions in high school students.

Causal illusions consist of believing that there is a causal relationship between events that are actually unrelated. This bias is associated with pseudoscience, stereotypes and other unjustified beliefs. Thus, it seems important to develop educational interventions to reduce them. To our knowledge, the only debiasing intervention designed to be used at schools was developed by Barberia et al. (Barberia et al. 2013 PLoS One 8, e71303 (doi:10.1371/journal.pone.0071303)), focusing on base rates, control conditions and confounding variables. Their assessment used an active causal illusion task where participants could manipulate the candidate cause. The intervention reduced causal illusions in adolescents but was only tested in a small experimental project. The present research evaluated it in a large-scale project through a collaboration with the Spanish Foundation for Science and Technology (FECYT), and was conducted in schools to make it ecologically valid. It included a pilot study (n = 287), a large-scale implementation (n = 1668; 40 schools) and a six-month follow-up (n = 353). Results showed medium-to-large and long-lasting effects on the reduction of causal illusions. To our knowledge, this is the first research showing the efficacy and long-term effects of a debiasing intervention against causal illusions that can be used on a large scale through the educational system.

How Can Imaginal Retraining for Modifying Food Craving be Improved?

Imaginal retraining (IR) is an emerging intervention technique in which people imagine avoidance behaviors towards imagined foods or other substances, such as throwing them away. Although IR shows promise in reducing initial craving for a range of substances, including alcohol and tobacco, effects appear less robust for craving for energy-dense foods. This raises the question of how IR for food craving can be improved. Here, we address this question informed by emerging findings from IR dismantling studies and the field of regular cognitive bias modification training paradigms. Based on current insights, we suggest the most optimal 'craving-reduction' effects for energy-dense food can likely be expected for IR that includes an overt motor movement. While it is not yet clear what movement works best for food, we suggest a tailored movement or Go/No-Go-based stop movement has the potential to be most effective. The most likely mechanism in reducing craving is cue-devaluation of trained vivid craving images regarding specific energy-dense food products. Future work is needed that investigates and assess the underlying mechanisms (e.g., updating beliefs; cue-devaluation), task characteristics (e.g., IR instructions; specific motor movements) and individual characteristics (e.g., perceived craving; vividness of food imagination) that determine IR effects.

(Ir)rationality and cognitive biases in large language models.

Do large language models (LLMs) display rational reasoning? LLMs have been shown to contain human biases due to the data they have been trained on; whether this is reflected in rational reasoning remains less clear. In this paper, we answer this question by evaluating seven language models using tasks from the cognitive psychology literature. We find that, like humans, LLMs display irrationality in these tasks. However, the way this irrationality is displayed does not reflect that shown by humans. When incorrect answers are given by LLMs to these tasks, they are often incorrect in ways that differ from human-like biases. On top of this, the LLMs reveal an additional layer of irrationality in the significant inconsistency of the responses. Aside from the experimental results, this paper seeks to make a methodological contribution by showing how we can assess and compare different capabilities of these types of models, in this case with respect to rational reasoning.

A randomized controlled trial modifying insomnia-consistent interpretation bias in students.

This study aimed to determine the causal role of insomnia-consistent interpretation bias within the cognitive model of insomnia, by modifying this bias in students experiencing subclinical levels of insomnia and assessing subsequent effects on sleep parameters. A sample of 128 students underwent randomization to receive either a single session of online Cognitive Bias Modification-Interpretation (CBM-I) or a sham training. Participants then tracked their pre-sleep worry and sleep parameters for seven consecutive days. Interpretation bias was assessed using an encoding-recognition task specifically designed for insomnia-related interpretation bias. The CBM-I manipulation utilized ambiguous scenarios to redirect participants away from making insomnia-related interpretations. Results revealed that CBM-I effectively decreased insomnia-consistent interpretation bias compared to the sham treatment, with interpretation bias being absent post-training in the CBM-I group. This reduction did not lead to improvements in pre-sleep worry or any sleep parameters. This study has been the first to investigate the causal role of interpretation bias on symptoms of insomnia. Although results indicated this bias to be modifiable, its causality within the cognitive model proves to be more complicated. Future research focusing on optimization of cognitive bias modifications could shed more light on the effects of biased cognitions on insomnia symptoms.

Episodic future thinking and psychopathology: A focus on depression and suicide risk.

Episodic future thinking (EFT), the ability to imagine future autobiographical events, is both an everyday and clinically significant cognitive process. With a focus on depression and suicidality, here we discuss evidence connecting EFT with psychopathology. Emotional valence of imagined future events has emerged as the most widely established feature of EFT detected to date, with less positive EFT being associated with depressive symptoms and suicidal thoughts and behaviors. This pattern may not be merely a byproduct of sadness or anhedonia. Promising directions for future research include clarifying the temporal association between EFT and clinical outcomes, investigating the potential benefits and drawbacks of positive EFT, and refining assessments for youth to measure EFT either preceding or soon after onset of psychopathology.

Prenatal affective cognitive training to reduce the risk of postpartum depression (PACT): study protocol for a randomized controlled trial.

BACKGROUND: Postpartum depression (PPD) affects 30-50% of women with a history of previous depression or bipolar disorder and 8% of women with no history of depression. Negative cognitive biases in the perception of infant cues and difficulties with emotion regulation are replicated risk factors. Current interventions focus on detecting and treating rather than preventing PPD. The aim of this randomized controlled intervention trial is therefore to investigate the potential prophylactic effects of prenatal affective cognitive training for pregnant women at heightened risk of PPD. METHODS: The study will enrol a total of 292 pregnant women: 146 at high risk and 146 at low risk of PPD. Participants undergo comprehensive assessments of affective cognitive processing, clinical depressive symptoms, and complete questionnaires at baseline. Based on the responses, pregnant women will be categorized as either at high or low risk of PPD. High-risk participants will be randomized to either prenatal affective cognitive training (PACT) or care as usual (CAU) immediately after the baseline testing. The PACT intervention is based on emerging evidence for efficacy of affective cognitive training approaches in depression, including cognitive bias modification, attention bias modification, mindfulness-inspired emotion regulation exercises, and working memory training. Participants randomised to PACT will complete five individual computerised and virtual reality-based training sessions over 5 weeks. The primary outcome is the difference between intervention arms in the incidence of PPD, assessed with an interview 6 months after birth. We will also assess the severity of depressive symptoms, rated weekly online during the first 6 weeks postpartum. DISCUSSION: The results will have implications for future early prophylactic interventions for pregnant women at heightened risk of PPD. If the PACT intervention reduces the incidence of PPD, it can become a feasible, non-invasive prophylactic strategy during pregnancy, with positive mental health implications for these women and their children. TRIAL REGISTRATION: ClinicalTrials.gov NCT06046456 registered 21-09-2023, updated 08-07-2024.

The role of cognitive biases involving selective interrogation of taste-based information in sugar-sweetened beverage consumption.

BACKGROUND AND OBJECTIVES: Consumption of sugar-sweetened beverages (SSBs) is a global public health issue. Consequently, there is strong interest in advancing understanding of the cognitive mechanisms that underpin excessive SSB consumption. This work proposes that selective interrogation of taste-based characteristics (e.g., flavour), rather than health-based characteristics (e.g., sugar content), of beverages is associated with greater SSB choice and consumption. METHODS: To evaluate this novel hypothesis, undergraduate students (n = 210) were recruited to complete self-report measures of SSB consumption, motivation and success in reducing SSB consumption and unhealthy eating more broadly, as well as a novel selective interrogation assessment task. This task provided participants with the opportunity to selectively interrogate taste-based and health-based characteristics of various mystery beverages. RESULTS: Results supported the hypothesis that greater selective interrogation of taste-based characteristics, rather than health-based characteristics, of beverages is associated with greater SSB choice and consumption. Additionally, results revealed that greater selective interrogation of taste-based characteristics was associated with decreased motivation to reduce SSB consumption and decreased motivation and success to reduce unhealthy consumption more broadly. LIMITATIONS: The current study did not evaluate whether selective interrogation of taste-based characteristics of beverages predicted actual SSB consumption. CONCLUSION: These findings provide novel evidence for the potential role of selective interrogation of taste-based characteristics of beverages in SSB choice and consumption. An important implication of these findings is that in order for interventions focusing on front-of-package nutrition labels to be effective in reducing unhealthy consumption, it is necessary that individuals are selectively interrogating this 'health-based' information.

The Ambiguous Cue Task: Measurement reliability of an experimental paradigm for the assessment of interpretation bias and associations with mental health.

Interpretation biases in the processing of ambiguous affective information are assumed to play an important role in the onset and maintenance of emotional disorders. Reports of low reliability for experimental measures of cognitive biases have called into question previous findings on the association of these measures with markers of mental health and demonstrated the need to systematically evaluate measurement reliability for measures of cognitive biases. We evaluated reliability and correlations with self-report measures of mental health for interpretation bias scores derived from the Ambiguous Cue Task (ACT), an experimental paradigm for the assessment of approach-avoidance behavior towards ambiguous affective stimuli. For a non-clinical sample, the measurement of an interpretation bias with the ACT showed high internal consistency (rSB = .91 - .96, N = 354) and acceptable 2-week test-retest correlations (rPearson = .61 - .65, n = 109). Correlations between the ACT interpretation bias scores and mental health-related self-report measures of personality and well-being were generally small (r ≤ |.11|) and statistically not significant when correcting for multiple comparisons. These findings suggest that in non-clinical populations, individual differences in the interpretation of ambiguous affective information as assessed with the ACT do not show a clear association with self-report markers of mental health. However, in allowing for a highly reliable measurement of interpretation bias, the ACT provides a valuable tool for studies considering potentially small effect sizes in non-clinical populations by studying bigger samples as well as for work on clinical populations, for which potentially greater effects can be expected.

Neurophysiological Pathways of Unconscious Emotion Processing in Depression: Insights from a simultaneous EEG-fMRI Measurement.

BACKGROUND: Major depressive disorder (MDD) is characterized by strong emotional dysregulation. Mechanisms driving the negative affect in depression may be fast processes existing on an unconscious level. METHODS: A priming task was conducted using simultaneous EEG-fMRI measurement involving presentation of facial expressions (happy, sad, neutral) to examine the neurophysiological pathway of biased unconscious emotion processing in MDD. Priming prior to a target emotion created unconscious (16.7 ms primer) and conscious (150 ms primer) trials. A large sample of N = 126 was recruited, containing healthy controls (HC; n = 66; 37 women) and MDD (n = 60; 31 women). RESULTS: HC showed a shorter reaction time in happy, but not in sad or neutral trials compared to MDD. N170 amplitudes were lower in trials with unconscious compared to conscious primer presentation. N170 amplitudes correlated with cortical (right fusiform gyrus (FFG), right middle temporal gyrus, right inferior temporal gyrus, left supplementary motor area, right middle frontal gyrus) and subcortical brain regions (right amygdala). The strength of N170 and brain activity correlation increased when the stimulus was consciously presented. Presented emotions did not affect the correlation of N170 values and brain activity. CONCLUSIONS: Our findings show that MDD may exhibit biased emotion regulation abilities at a behavioral and neurophysiological level. Face-sensitive event-related potentials demonstrate a correlation with heightened brain activity in regions associated with both face recognition (FFG) and emotion processing (amygdala). These findings are evident in both MDD and HC, with lower effect sizes in MDD indicating reduced emotion recognition and processing abilities.

Predictors of clinical insight in first-episode psychosis: Different patterns in men and women.

BACKGROUND: We aimed to explore gender-related differences in the associations of insight impairment with clinical symptoms, metacognition, and social cognition in psychosis. METHODS: Regression analysis of several clinical insight dimensions was conducted on the data from 116 men and 56 women with first-episode psychosis. Various clinical symptoms and measures of metacognition and social cognition were entered as predictors. RESULTS: In both men and women, delusions emerged as a strong predictor of all insight dimensions, and verbal hallucinations as a strong predictor of symptom relabelling. In men, certain negative symptoms as well as self-certainty, lack of self-reflectiveness, impaired theory of mind, attributional biases, and a jumping-to-conclusions bias were additional predictors of poor insight, while good insight was associated with depression, anxiety, avolition, blunted affect, and impaired emotional recognition. In women, poor insight was associated with a self-serving/externalising bias, impaired emotional recognition, and attention disorders. CONCLUSIONS: Poor insight in first-episode psychosis is strongly linked to deficits in metacognition and social cognition, with marked differences between men and women with respect to the specific skills involved in the impairment. Meanwhile, good insight is linked to a variety of affective manifestations in men. These findings suggest new avenues for more targeted cognitive interventions to improve clinical insight in psychosis.

A global survey of the attitudes and perspectives of cognitive bias in forensic anthropology.

It is now well established that decision making can be susceptible to cognitive bias in a broad range of fields, with forensic science being no exception. Previously published research has revealed a bias blind spot in forensic science where examiners do not recognise bias within their own domain. A survey of 101 forensic anthropology practitioners (n = 52) and students (n = 38) was undertaken to assess their level of awareness of cognitive bias and investigate their attitudes towards cognitive bias within forensic anthropology. The results revealed that the forensic anthropology community (∼90%) had a high level of awareness of cognitive bias. Overall ∼89% expressed concerns about cognitive bias in the broad discipline of forensic science, their own domain of forensic anthropology, and in the evaluative judgments they made in reconstruction activities, identifying a significant reduction in the bias blind spot. However, more than half of the participants believed that bias can be reduced by sheer force of will, and there was a lack of consensus about implementing blinding procedures or context management. These findings highlight the need to investigate empirically the feasibility of proposed mitigating strategies within the workflow of forensic anthropologists and their capabilities for increasing the transparency in decision making.

Cost-benefit considerations of the biased diagnostician.

OBJECTIVES: In the cognitive process of establishing a diagnosis, the performance of a diagnostician can be characterized in terms of sensitivity and specificity. The aims of the present study are to analyze in quantitative terms how cognitive bias affects the performance of a diagnostician, and how a diagnostician's biased decision making is further influenced by personal cost-benefit considerations. METHODS: The test matrices of two sequential diagnostic tests are manipulated according to the rules of linear algebra, using multiplication of the second with the first test matrix to calculate their joint test characteristics. The decision tree and receiver operating characteristic (ROC) of a biased and unbiased diagnostician are used to calculate which combination of test characteristics maximizes the expected utility value. RESULTS: Biased diagnosticians cannot establish a diagnosis beyond their own limited or distorted level of understanding. An unbiased and a biased diagnostician alike adjust their choice of test characteristics according to their different cost-benefit estimation of the various test outcomes. From the perspective of an unbiased diagnostician, the choices made by a biased diagnostician appear to invert reality. However, the same appearance of inverted reality is perceived by the biased diagnostician, judging the choices made by the unbiased diagnostician. CONCLUSIONS: As a general principle, human testers cannot test beyond their own level of understanding. They only see what they know. As they base their judgment on preconceived notions about the utilities associated with different test outcomes, human testers also tend to only know what they want to know.

The impact of hindsight bias on the diagnosis of perioperative events by anesthesia providers: A multicenter randomized crossover study.

STUDY OBJECTIVE: Hindsight bias is the tendency to overestimate the predictability of an event after it has already occurred. We aimed to evaluate whether hindsight bias influences the retrospective interpretation of clinical scenarios in the field of anesthesiology, which relies on clinicians making rapid decisions in the setting of perioperative adverse events. DESIGN: Two clinical scenarios were developed (intraoperative hypotension and intraoperative hypoxia) with 3 potential diagnoses for each. Participants completed a crossover study reviewing one case without being informed of the supposed ultimate diagnosis (i.e., no 'anchor' diagnosis), referred to as their foresight case, and the other as a hindsight case wherein they were informed in the leading sentence of the scenario that 1 of the 3 conditions provided was the ultimate diagnosis (i.e., the diagnosis the participant might 'anchor' to if given this information at the start). Participants were randomly assigned to (1) which scenario (hypotension or hypoxia) was presented as the initial foresight case and (2) which of the 3 potential diagnoses for the second case (the hindsight case, which defaulted to whichever case the participant was not assigned for the first case) was presented as the ultimate diagnosis in the leading sentence in a 2 (scenario order) x 3 (hindsight case anchor) between-subjects factorial design (6 possible randomization assignments). SETTING: Two academic medical centers. PARTICIPANTS: Faculty, fellow, and resident anesthesiologists and certified nurse anesthetists (CRNAs). INTERVENTIONS: None. MEASUREMENTS: After reading each clinical scenario, participants were asked to rate the probability (%) of each of three potential diagnoses to have caused the hypotension or hypoxia. Compositional data analysis (CoDA) was used to compare whether diagnosis probabilities differ between the hindsight and the foresight case. MAIN RESULTS: 113 participants completed the study. 59 participants (52%) were resident anesthesiologists. Participants randomized to the hypotension scenario as a hindsight case were 2.82 times more likely to assign higher probability to the pulmonary embolus diagnosis if provided as an anchor (95% CI, 1.35-5.90; P = 0.006) and twice as likely to assign higher probability to the myocardial infarction diagnosis if provided as an anchor (95% CI, 1.12-3.58; P = 0.020). Participants randomized to the hypoxia scenario as a hindsight case were 1.78 times more likely to assign higher probability to the mainstem bronchus intubation diagnosis if provided in the anchor statement (95% CI, 1.00-3.14; P = 0.048) and 3.72 times more likely to assign higher probability to the pulmonary edema diagnosis if provided as an anchor (95% CI, 1.88-7.35; P < 0.001). CONCLUSIONS: Hindsight bias influences the clinical diagnosis probabilities assigned by anesthesia providers. Clinicians should be educated on hindsight bias in perioperative medicine and be cognizant of the effect of hindsight bias when interpreting clinical outcomes.

Clinical reasoning-the essentials for teaching medical students, trainees and non-medical healthcare professionals.

Clinical reasoning is fundamental for effective clinical practice. Traditional consultation models for teaching clinical reasoning or conventional approaches for teaching students how to make a diagnosis or management plan that rely on learning through observation only, are increasingly recognised as insufficient. There are also many challenges to supporting learners in developing clinical reasoning over time as well as across different clinical presentations and contexts. These challenges are compounded by the differences in how experts and novices make sense of clinical information, and the different cognitive processes each use when processing and communicating this information using precise medical language. Diagnostic errors may be due to cognitive biases but also, in a majority of cases, due to a lack of clinical knowledge. Therefore, effective educational strategies to develop clinical reasoning include identifying learners' knowledge gaps, using worked examples to prevent cognitive overload, promoting the use of key features and practising the construction of accurate problem representations. Deliberate reflection on diagnostic justification is also recommended, and overall, contributes to a growing number of evidence-based and theory-driven educational interventions for reducing diagnostic errors and improving patient care.

Are lateralized and bold fish optimistic or pessimistic?

Cognitive bias is defined as the influence of emotions on cognitive processes. The concept of the cognitive judgement bias has its origins in human psychology but has been applied to animals over the past 2 decades. In this study we were interested in determining if laterality and personality traits, which are known to influence learning style, might also be correlated with a cognitive bias in the three-spined sticklebacks (Gasterosteus aculeatus). We used the judgement bias test with the go/no-go procedure where fish were first trained to discriminate between a black and white card and, after reaching a minimum learning criterion, tested their response to an ambiguous card (grey). Optimistic subjects were expected to have a high expectation of reward associated with an ambiguous stimulus, whereas pessimistic subjects a high expectation of non-reward. We used an emergence and a mirror test to quantify boldness and laterality, respectively. We hypothesised that male, bolder and more strongly lateralized fish would be more optimistic than female, shy and less strongly lateralised fish. We found that males and more strongly lateralized fish were more optimistic than females and less strongly lateralized fish. In addition, bold males were more optimistic than shy males as we predicted, but females showed the opposite pattern. Finally, fish trained on the black colour card learned the training task faster than those trained on a white card. Our results indicate that both laterality and personality traits are linked to animals' internal states (pessimistic or optimistic outlooks) which likely has broad implications for understanding animal behaviour particularly in a welfare context.

[Caregiver-patient communication: A complex process]. / Communication soignant-soigné : un processus complexe.

Caregiver-client communication is a process influenced by many specific elements arising from the context, the content and the form of the message, but also from the inner life of the patient and the caregiver. All these specific factors have an impact on the transmission and reception of the message.

The effects of cognitive bias, examiner expertise, and stimulus material on forensic evidence analysis.

Forensic examiners have come under scrutiny due to high-profile exonerations, highlighting the consequences that contextual bias can have on investigations. Researchers have proposed solutions to reduce the effects of bias including blind testing and redacting task-irrelevant information. Practitioners have concerns over the limitations of some of this research that uses untrained students to examine complex pieces of forensic evidence (e.g., fingerprints) (1; but see 2 for studies including trained experts and/or actual casework). This study sought to (a) examine the effect of contextual bias on examiners' evaluation of forensic evidence by varying the amount of pre-comparison information available to participants, (b) compare student and expert examiners' performance and their vulnerability to contextual bias, and (c) examine the effects of contextual bias on examiners' evaluation of different types of forensic evidence. Expert fingerprint examiners and student participants were presented with varying amounts of pre-comparison case information and compared matching and non-matching fingerprint and footwear impression evidence. Results suggest no effects of blinding examiners from case information or redacting task-irrelevant information. As expected, expert fingerprint examiners were more likely to correctly identify matching fingerprints and correctly exclude non-matching fingerprints than students. However, expert fingerprint examiners were no better than student participants at comparing footwear impression evidence. These findings suggest that sample, stimulus selection, and discipline-specific training matter when investigating bias in forensic decision making. These findings suggest caution when using forensic stimuli with student samples to investigate forensic decision-making and highlight the need for more research on redaction procedures.

The Affective Bias Test and Reward Learning Assay: Neuropsychological Models for Depression Research and Investigating Antidepressant Treatments in Rodents.

The Affective Bias Test (ABT) quantifies acute changes in affective state based on the affective biases they generate in an associative reward learning task. The Reward Learning Assay (RLA) provides a control assay for the ABT and reward-induced biases generated in this model are sensitive to changes in core affective state. Both tasks involve training animals to associate a specific digging substrate with a food reward. Animals learn to discriminate between two digging substrates placed in ceramic bowls, one rewarded and one unrewarded. In the ABT, the animal learns two independent substrate-reward associations with a fixed reward value following either an affective state or drug manipulation, or under control conditions. Affective biases generated are quantified in a choice test where the animals exhibit a bias (make more choices) for one of the substrates which is specifically related to affective state at the time of learning. The ABT is used to investigate biases generated during learning as well as modulation of biases associated with past experiences. The RLA follows a similar protocol, but the animal remains in the same affective state throughout and a reward-induced bias is generated by pairing one substrate with a higher value reward. The RLA provides a control to determine if drug treatments affect memory retrieval more generally. Studies in depression models and following environmental enrichment suggest that reward-induced biases are sensitive to core changes in affective state. Each task offers different insights into affective processing mechanisms and may help improve the translational validity of animal studies and benefit pre-clinical drug development. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Bowl digging and discrimination training Basic Protocol 2: The reward learning assay Basic Protocol 3: The affective bias test - new learning Basic Protocol 4: The affective bias test - modulation of affective biases associated with past experiences.

Ten misconceptions regarding decision-making in critical care.

Diagnostic errors are prevalent in critical care practice and are associated with patient harm and costs for providers and the healthcare system. Patient complexity, illness severity, and the urgency in initiating proper treatment all contribute to decision-making errors. Clinician-related factors such as fatigue, cognitive overload, and inexperience further interfere with effective decision-making. Cognitive science has provided insight into the clinical decision-making process that can be used to reduce error. This evidence-based review discusses ten common misconceptions regarding critical care decision-making. By understanding how practitioners make clinical decisions and examining how errors occur, strategies may be developed and implemented to decrease errors in Decision-making and improve patient outcomes.

Trust but verify: The biasing effects of witness opinions and background knowledge in workplace investigations.

INTRODUCTION: A unique feature of workplace investigations is the familiarity that investigators and witnesses have with the factors involved in the adverse incident. Familiarity creates expectations that can shape investigators' and witnesses' assumptions and opinions. The current research examined the biasing effect of non-factual witness claims on investigators' judgments. These claims, which we call 'uncheckable,' included opinions about factors involved in the event and the future. We also examined how participants' a priori knowledge of an employee's history influenced their judgments. METHOD: This experiment used a 2 (background information: control or unsafe) × 2 (uncheckable content: neutral or unsafe) between-subjects design. Participants were provided with background information about a worker (control or unsafe history) and a witness statement about a workplace event that contained uncheckable claims (neutral or worker as unsafe). We tested how our manipulations biased participants' judgments of: (i) the cause of the event, (ii) the witness's confidence and credibility, and (iii) the diagnosticity of the witness's account. We also tested if biasing background information affected how factual participants found the witness's statement. RESULTS: Biasing uncheckable information (i.e., opinions) affected participants' judgments of event cause (ηp2 = 0.033) and increased their ratings of witness confidence (ηp2 = 0.074). Biasing background information about a worker affected participants' judgments of the cause of the event (ηp2 = 0.088), the diagnostic value of the witness statement (ηp2 = 0.054), and the number of factual claims in the witness statement, resulting in more uncheckable claims being misclassified as potential facts (ηp2 = 0.18). CONCLUSION: This experiment demonstrated the significant effect that non-factual witness statements and irrelevant background information can have on the interpretation of evidence and judgments about the cause of events. PRACTICAL APPLICATION: Understanding how contextual information can bias investigative judgment helps workplace investigators manage its influence in their judgment practices.