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BackgroundThe behavioural and emotional profiles underlying adolescent self-harm, and its developmental risk factors, are relatively unknown. We aimed to identify sub-groups of young people who self-harm (YPSH) and longitudinal predictors leading to self-harm.MethodsParticipants were from the Millennium Cohort Study (n=10,827). A clustering algorithm identified sub-groups who self-harmed with different behavioural and emotional profiles at age 14. Feature selection analyses were then used to identify longitudinal predictors of self-harming behaviour.FindingsThere were two distinct sub-groups at age 14: a smaller group (n = 379) who reported a long history of psychopathology, and a second group (n = 905) without. Notably, both groups could be predicted almost a decade before the reported self-harm. They were similarly characterised by sleep problems and low self-esteem, but there was developmental differentiation. From an early age, the first group had poorer emotion regulation, were bullied, and their caregivers faced emotional challenges. The second group showed less consistency in early childhood, but later reported more willingness to take risks and less security with peers/family.InterpretationOur results uncover two distinct pathways to self-harm: a ‘psychopathology’ pathway, associated with early and persistent emotional difficulties and bullying; and an ‘adolescent risky behaviour’ pathway, where risk-taking and external challenges emerge later into adolescence and predict self-harm. These two pathways have long developmental histories, providing an extended window for interventions as well as potential improvements in the identification of children at risk, biopsychosocial causes, and treatment or prevention of self-harm.FundingThis study was supported by the UK Medical Research Council, Templeton World Charitable Foundation, and a Gates Cambridge Scholarship awarded to SU.

UNLABELLED: A child's socio-economic environment can profoundly affect their development. While existing literature focusses on simplified metrics and pair-wise relations between few variables, we aimed to capture complex interrelationships between several relevant domains using a broad assessment of 519 children aged 7-9 years. Our analyses comprised three multivariate techniques that complimented each other, and worked at different levels of granularity. First, an exploratory factor analysis (principal component analysis followed by varimax rotation) revealed that our sample varied along continuous dimensions of cognition, attitude and mental health (from parallel analysis); with potentially emerging dimensions speed and socio-economic status (passed Kaiser's criterion). Second, k-means cluster analysis showed that children did not group into discrete phenotypes. Third, a network analysis on the basis of bootstrapped partial correlations (confirmed by both cross-validated LASSO and multiple comparisons correction of binarised connection probabilities) uncovered how our developmental measures interconnected: educational outcomes (reading and maths fluency) were directly related to cognition (short-term memory, number sense, processing speed, inhibition). By contrast, mental health (anxiety and depression symptoms) and attitudes (conscientiousness, grit, growth mindset) showed indirect relationships with educational outcomes via cognition. Finally, socio-economic factors (neighbourhood deprivation, family affluence) related directly to educational outcomes, cognition, mental health, and even grit. In sum, cognition is a central cog through which mental health and attitude relate to educational outcomes. However, through direct relations with all components of developmental outcomes, socio-economic status acts as a great 'unequaliser'. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12144-021-02232-2.

Attentional bias for threat is an adaptive feature of human psychology, but may become maladaptive in anxiety-related disorders, causing distress, distraction, and distorted perception of danger. Reaction time measures have revealed automatic, covert attention biases to threat, whereas eye tracking has revealed voluntary biases over a larger timescale, with monitoring or avoidance depending on context. Recently, attentional bias for threat has been studied as a conditioned fear response, providing new insight into how attentional biases are acquired and inhibited through learning experiences. However, very few studies have examined voluntary gaze biases during fear learning. In a novel eye tracking paradigm (N = 78), we examine the overt components of attentional bias to threat and safety cues. We found that threat cues, but not safety cues, elicited an initial orienting bias, as well as sustained monitoring bias across 10-second trials. This collective “vigilance” response to threat cues was insensitive to extinction, whereas condition fear responding revealed by pupil size and self-report ratings showed marked extinction. Vigilance may be less prone to extinction, compared to autonomic arousal, because eye movements require less energy than preparing the body for defensive behavior. Implications for understanding vigilance in PTSD are considered.

Funder: University of Cambridge, Due to increasing ease of use and ability to quickly collect large samples, online behavioural research is currently booming. With this popularity, it is important that researchers are aware of who online participants are, and what devices and software they use to access experiments. While it is somewhat obvious that these factors can impact data quality, the magnitude of the problem remains unclear. To understand how these characteristics impact experiment presentation and data quality, we performed a battery of automated tests on a number of realistic set-ups. We investigated how different web-building platforms (Gorilla v.20190828, jsPsych v6.0.5, Lab.js v19.1.0, and psychoJS/PsychoPy3 v3.1.5), browsers (Chrome, Edge, Firefox, and Safari), and operating systems (macOS and Windows 10) impact display time across 30 different frame durations for each software combination. We then employed a robot actuator in realistic set-ups to measure response recording across the aforementioned platforms, and between different keyboard types (desktop and integrated laptop). Finally, we analysed data from over 200,000 participants on their demographics, technology, and software to provide context to our findings. We found that modern web platforms provide reasonable accuracy and precision for display duration and manual response time, and that no single platform stands out as the best in all features and conditions. In addition, our online participant analysis shows what equipment they are likely to use.

IntroductionDecentering describes the ability to voluntarily adopt an objective self-perspective from which to notice internal, typically distressing, stressors (eg, difficult thoughts, memories and feelings). The reinforcement of this skill may be an active ingredient through which different psychological interventions accrue reductions in anxiety and/or depression. However, it is unclear if decentering can be selectively trained at a young age and if this might reduce psychological distress. The aim of the current trial is to address this research gap.Methods and analysisAdolescents, recruited from schools in the UK and Ireland (n=57 per group, age range=16–19 years), will be randomised to complete 5 weeks of decentering training, or an active control group that will take part in a combination of light physical exercise and cognitive training. The coprimary training outcomes include a self-reported decentering inventory (ie, the Experiences Questionnaire) and the momentary use of decentering in response to psychological stressors, using experience sampling. The secondary mental health outcomes will include self-reported inventories of depression and anxiety symptoms, as well as psychological well-being. Initial statistical analysis will use between-group analysis of covariance to estimate the effect of training condition on self-rated inventories, adjusted for baseline scores. Additionally, experience sampling data will be examined using hierarchical linear models.Ethics and disseminationThis study was approved by the Cambridge Psychology Research Ethics Committee, University of Cambridge (PRE.2019.109). Findings will be disseminated through typical academic routes including poster/paper presentations at (inter)national conferences, academic institutes and through publication in peer-reviewed journals.Trial registration numberISRCTN14329613.

Although implicit emotion regulation is thought to be critical for psychosocial development and mental wellbeing, few studies have investigated the neural underpinnings of this form of emotion regulation in children. We used a modified emotional Go/NoGo block design fMRI task to explore the neural correlates of implicit emotion regulation and individual differences in a sample of 40 children (50% female, mean age = 8.65 ± 0.77). Conditions included happy, sad, neutral, and scrambled faces as implicit distractors within the actual Go/NoGo targets. We used a relatively standard preprocessing pipeline via fMRIprep, with T-contrasts for response inhibition and emotional effects, and a nonparametric multiple comparisons procedure, with SnPM, for our group-level analysis. There were multiple significant response inhibition effects, including larger NoGo vs Go activation in the IFG, insula, and MCC/ACC. Valence effects showed significantly greater right putamen activity for the Sad NoGo vs Go contrast and greater bilateral putamen and right pallidum activity for the Happy Go vs Sad Go contrast. These results provide preliminary findings of neural substrates, particularly the putamen, that may be associated with implicit emotion regulation in children.

Psychological research is increasingly moving online, where web-based studies allow for data collection at scale. Behavioural researchers are well supported by existing tools for participant recruitment, and for building and running experiments with decent timing. However, not all techniques are portable to the Internet: While eye tracking works in tightly controlled lab conditions, webcam-based eye tracking suffers from high attrition and poorer quality due to basic limitations like webcam availability, poor image quality, and reflections on glasses and the cornea. Here we present MouseView.js, an alternative to eye tracking that can be employed in web-based research. Inspired by the visual system, MouseView.js blurs the display to mimic peripheral vision, but allows participants to move a sharp aperture that is roughly the size of the fovea. Like eye gaze, the aperture can be directed to fixate on stimuli of interest. We validated MouseView.js in an online replication (N = 165) of an established free viewing task (N = 83 existing eye-tracking datasets), and in an in-lab direct comparison with eye tracking in the same participants (N = 50). Mouseview.js proved as reliable as gaze, and produced the same pattern of dwell time results. In addition, dwell time differences from MouseView.js and from eye tracking correlated highly, and related to self-report measures in similar ways. The tool is open-source, implemented in JavaScript, and usable as a standalone library, or within Gorilla, jsPsych, and PsychoJS. In sum, MouseView.js is a freely available instrument for attention-tracking that is both reliable and valid, and that can replace eye tracking in certain web-based psychological experiments., Templeton World Charity Foundation (grant TWCF0159) UK Medical Research Council (grant MC-A0606-5PQ41)

Disgust is an adaptation forged under the selective pressure of pathogens. Yet disgust may cause problems in contemporary societies because of its propensity for "false positives" and resistance to corrective information. Here, we investigate whether disgust, as revealed by oculomotor avoidance, might be reduced through the noncognitive process of habituation. In each of three experiments, we repeatedly exposed participants to the same pair of images, one disgusting and one neutral, and recorded gaze. Experiment 1 (N = 104) found no decline in oculomotor avoidance of the disgusting image after 24 prolonged exposures. Experiment 2 (N = 99) replicated this effect and demonstrated its uniqueness to disgust. In Experiment 3 (N = 93), we provided a gaze-contingent reward to ensure perceptual contact with the disgusting image. Participants looked almost exclusively at the disgusting image for 5 min but resumed baseline levels of oculomotor avoidance once the reward ceased. These findings underscore the challenge of reducing disgust. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The patient-physician relationship is a critical determinant for patient health outcomes. Verbal and non-verbal communication, such as eye gaze, are vital aspects of this bond. Neurobiological studies indicate that oxytocin may serve as a link between increased eye gaze and social bonding. Therefore, oxytocin signaling could serve as a key factor influencing eye gaze as well as the patient-physician relationship. We aimed to test the effects of oxytocin on gaze to the eyes of the physician and the patient-physician relationship by conducting a randomized placebo-controlled crossover trial in healthy volunteers with intranasally administered oxytocin (24IU, number 2018-004081-34). Eye gaze of sixty-eight male volunteers was studied using eye-tracking. Volunteers engaged in a simulated video call consultation with a physician who provided information about vaccination against the human papilloma virus. Relationship outcomes, including trust, satisfaction and perceived physician communication style, were measured using questionnaires and corrected for possible confounders (social anxiety and attachment orientation). Additional secondary outcome measures were recall of information and pupil diameter and exploratory outcomes were mood and anxiety. Oxytocin did not affect eye tracking parameters of volunteers’ gaze towards the eyes of the physician. Moreover, oxytocin did not affect parameters of bonding between volunteers and the physician, nor other secondary and exploratory outcomes. Bayesian hypothesis testing provided evidence for the absence of effects. These results contradict the notion that oxytocin affects eye gaze patterns or bonding.

Summary Rotten food, maggots, bodily waste—all elicit disgust in humans. Disgust promotes survival by encouraging avoidance of disease vectors 1 but is also implicated in prejudice toward minority groups; avoidance of environmentally beneficial foods, such as insect protein; and maladaptive avoidance behavior in neuropsychiatric conditions. 2 , 3 , 4 , 5 Unlike fear, pathological disgust is not improved substantially by exposure therapy clinically, 6 nor in experimental work does behavioral avoidance of disgusting images habituate following prolonged exposure. 7 , 8 Under normal physiological conditions, perception of disgusting stimuli disrupts myoelectrical rhythms in the stomach, 9 , 10 , 11 , 12 , 13 inducing gastric dysrhythmias that correlate with neural signatures of disgust. 11 However, the causal role of gastric rhythm in disgust avoidance is unknown. We manipulated gastric rhythm using domperidone, a peripheral dopamine D2/D3 antagonist and common anti-emetic, at a dose (10 mg) that acts to convert gastric dysrhythmias to normal rhythms. 9 In a preregistered, randomized, double-blind, placebo-controlled crossover design in 25 healthy volunteers (aged 18–25), we measured the effects of domperidone on core disgust avoidance, using eye tracking to measure implicit (oculomotor) avoidance of disgusting images (feces) before and after an “exposure” intervention (monetary reinforcement for looking at disgusting images). 7 , 8 We find that domperidone significantly reduces oculomotor disgust avoidance following incentivized exposure. This suggests that domperidone may weaken the “immunity” of disgust to habituation, putatively by reducing gastric dysrhythmias during incentivized engagement with disgusting stimuli. This indicates a causal role for disgust-related visceral changes in disgust avoidance, supporting the hypothesis that physiological homeostasis contributes to emotional experience.

Language and reading acquisitions are strongly associated with a child’s socioeconomic status (SES). There are a number of potential explanations for this relationship. We explore one potential explanation—a child’s SES is associated with how children discriminate word-like sounds (i.e., phonological processing), a foundational skill for reading acquisition. Magnetoencephalography data from a sample of 71 children (aged 6 years and 11 months–12 years and 3 months), during a passive auditory oddball task containing word and nonword deviants, were used to test “where” (which sensors) and “when” (at what time) any association may occur. We also investigated associations between cognition, education, and this neurophysiological response. We report differences in the neural processing of word and nonword deviant tones at an early N200 component (likely representing early sensory processing) and a later P300 component (likely representing attentional and/or semantic processing). More interestingly we found “parental subjective” SES (the parents rating of their own relative affluence) was convincingly associated with later responses, but there were no significant associations with equivalized income. This suggests that the SES as rated by their parents is associated with underlying phonological detection skills. Furthermore, this correlation likely occurs at a later time point in information processing, associated with semantic and attentional processes. In contrast, household income is not significantly associated with these skills. One possibility is that the subjective assessment of SES is more impactful on neural mechanisms of phonological processing than the less complex and more objective measure of household income.

Magnetoencephalography (MEG) is an exceptionally useful tool to study child development. It measures brain waves: fluctuations in the magnetic field around the head caused by changes in the local field potential of neuronal populations that fire in synchrony. MEG has a high-temporal resolution, and a reasonable degree of spatial precision. It offers insights into how the brain responds to events, how brain rhythms affect perception and performance, and how different areas talk to each other. In addition to its scientific benefits, MEG is safe, silent, and requires relatively little setup time. In this chapter, the authors outline the origins of the MEG signal, provide practical tips specific to testing children, and describe a wide variety of analysis methods.

Funder: Medical Research Council; FundRef: http://dx.doi.org/10.13039/501100000265, Objective: There has been widespread concern that so-called lockdown measures, including social distancing and school closures, could negatively impact children’s mental health. However, there has been little direct evidence of any association due to the paucity of longitudinal studies reporting mental health before and during the lockdown. This present study provides the first longitudinal examination of changes in childhood mental health, a key component of an urgently needed evidence base that can inform policy and practice surrounding the continuing response to the COVID-19 pandemic. Methods: Mental health assessments on 168 children (aged 7.6–11.6 years) were taken before and during the UK lockdown (April–June 2020). Assessments included self-reports, caregiver reports, and teacher reports. Mean mental health scores before and during the UK lockdown were compared using mixed linear models. Results: A significant increase in depression symptoms during the UK lockdown was observed, as measured by the Revised Child Anxiety and Depression Scale (RCADS) short form. CIs suggest a medium-to-large effect size. There were no significant changes in the RCADS anxiety subscale and Strengths and Difficulties Questionnaire emotional problems subscale. Conclusions: During the UK lockdown, children’s depression symptoms have increased substantially, relative to before lockdown. The scale of this effect has direct relevance for the continuation of different elements of lockdown policy, such as complete or partial school closures. This early evidence for the direct impact of lockdown must now be combined with larger scale epidemiological studies that establish which children are most at risk and tracks their future recovery.

Disgust motivates avoidance of stimuli associated with pathogens. Although disgust primarily inhibits oral and epidermal contact, it may also inhibit perceptual contact, particularly given the outsize role of sensory qualities in eliciting disgust. To examine perceptual avoidance of disgust, we presented images of bodily products or spoiled food paired with neutral images for 12-s trials and recorded eye movements (Experiment 1; N = 127). We found that, overall, these disgusting images were not visually avoided compared to neutral images. However, viewing of disgusting images decreased with prolonged (within-trial) and repeated (between-trial) exposure, and these trends were predicted by self-reported disgust to the images. In Experiment 2 (N = 84), we replicated Experiment 1 with a novel set of disgusting images, as well as other unpleasant image categories (suicide, threat) and pleasant images. We found that disgusting stimuli were viewed less than the other unpleasant image categories, and we again found that viewing of disgusting images decreased with prolonged and repeated exposure. Further, we replicated the finding that disgust ratings predicted decreasing viewing of disgusting images, but only for prolonged exposure (within-trial). Unexpectedly, we found that disgust ratings predicted a similar pattern of decreasing viewing for the suicide and threat images as well. These findings suggest that disgust inhibits perceptual contact, but in competition with motivational processes that steer attention toward pathogen threats. We discuss the implications for measuring disgust with eye tracking. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

SummaryFor a century [1,2], studies of monozygotic and dizygotic twins have yielded estimates of trait heritability. The clever logic behind them is that while both types of twins share environments, their genetic overlap is different. Hence, larger trait correlations between monozygotic compared to dizygotic twins indicate heritability (nature), whereas similar correlations indicate shared environmental influences (nurture), and low correlations indicate shaping through non-shared environments (external influences and measurement error). While many have written on the assumptions that both types of twins share equal environments [3–5], and that parental genetics and environment are independent [6,7]; fewer have put their data where their mouth is. Here, the impacts of unmet assumptions were investigated using a generative mixture model of twin phenotypes. The results indicated that violations of the equal environments assumption yielded large overestimations of heritability and underestimations of shared environmental influences. On the other hand, when parental genetics shaped twins’ shared environments, only minor non-linear biases against heritability emerged. Finally, realistic levels of measurement error uniformly depressed estimates for genetic and shared environmental factors. In sum, twin studies are particularly susceptible to overestimation of genetic and non-shared environmental influences. This bias could explain why some traits, such as attitudes towards property taxes [8], show suspiciously high heritability without a biologically plausible mechanism. Particularly in the context of traits with convincing mechanisms of cultural transmission [9–11] and complex gene-environment interactions [6], researchers should not allow biases in twin studies to overestimate heritability.

BackgroundThere has been widespread concern that so-called ‘lockdown’ measures, including social distancing and school closures, could negatively impact children’s mental health. However, there has been little direct evidence of this impact due to the paucity of longitudinal studies reporting mental health before and during lockdown. This present study provides the first longitudinal examination of changes in childhood mental health, a key component of an urgently needed evidence base that can inform policy and practice surrounding the continuing response to the COVID-19 pandemic. MethodsMental health assessments on 168 children (aged 7.5-11.6 years) were taken before and during the UK lockdown. Assessments included self-reports, parent-reports, and teacher-reports. Mean mental health scores before and during the UK lockdown were compared using mixed linear models. FindingsA significant increase in depression symptoms during the UK lockdown was observed, as measured by the RCADS short form. Confidence intervals suggest a medium-to-large effect size. There were no significant changes in RCADS anxiety subscale and SDQ emotional problems subscale.InterpretationDuring the UK lockdown children’s depression symptoms have increased substantially, relative to before lockdown. The scale of this effect has direct relevance for the continuation of different elements of lockdown policy, such as complete or partial school closures. This early evidence for the direct impact of lockdown must now be combined with larger-scale epidemiological studies that establish which children are most at risk, and tracks their future recovery.FundingThis study was supported by grant TWCF0159 from the Templeton World Charity Foundation to DEA, and by the UK Medical Research Council. SU was supported by the Gates Cambridge Trust.

BackgroundThere is a well-established link between allergies and mental health. While both atopic and food allergies are associated with increased levels of depression and anxiety, it is unclear what the mechanism behind this relationship is. Several theories touch upon potential psychological mechanisms, but until now putative cognitive mechanisms of the link between mental health and allergies have been unexplored.MethodsWe employed tablet-based deep cognitive phenotyping, and also recorded mental health, socio-economic status, and allergies in 533 children aged 7-9 years. We then employed mediation analyses to test whether cognitive mechanisms mediated the association between allergies and mental health.FindingsIn line with previous research, we found children with allergies reported higher levels of anxiety and depression. Furthermore, compared to children without allergies, they showed faster processing speed, equal verbal short-term memory, and worse performance on tests of fluid reasoning, number sense, search organisation, and spatial short-term memory. We confirmed that these variables predicted allergic state using logistic regression. Most importantly, we found that cognition partially mediated the relationship between allergy and both anxiety and depression.InterpretationOur results suggest that allergies bias children towards particular cognitive profiles, which in turn are risk factors for anxiety and depression. This supports the view that early cognitive interventions could reduce the number of allergic children that develops comorbid psychiatric conditions.FundingThis study was supported by grant TWCF0159 from the Templeton World Charity Foundation to DEA, and by the UK Medical Research Council.

Due to its increasing ease-of-use and ability to quickly collect large samples, online behavioral research is currently booming. With this increasing popularity, it is important that researchers are aware of who online participants are, and what devices and software they use to access experiments. While it is somewhat obvious that these factors can impact data quality, it remains unclear how big this problem is. To understand how these characteristics impact experiment presentation and data quality, we performed a battery of automated tests on a number of representative setups. We investigated how different web-building platforms (Gorilla, jsPsych, Lab.js, and psychoJS/PsychoPy3), browsers (Chrome, Edge, Firefox, and Safari), and operating systems (mac OS and Windows 10) impact display time across 30 different frame durations for each software combination. In addition, we employed a robot actuator in representative setups to measure response recording across aforementioned platforms, and between different keyboard types (desktop and integrated laptop). We then surveyed over 200 000 participants on their demographics, technology, and software to provide context to our findings. We found that modern web-platforms provide a reasonable accuracy and precision for display duration and manual response time, but also identify specific combinations that produce unexpected variance and delays. While no single platform stands out as the best in all features and conditions, our findings can help researchers make informed decisions about which experiment building platform is most appropriate in their situation, and what equipment their participants are likely to have.

As in visual perception, information can be selected for prioritized processing at the expense of unattended representations in visual working memory (VWM). However, what is not clear is whether and how this prioritization degrades the unattended representations. We addressed two hypotheses. First, the representational quality of unattended items could be degraded as a function of the spatial distance to attended information in VWM. Second, the strength with which an item is bound to its location is degraded as a function of the spatial distance to attended information in VWM. To disentangle these possibilities, we designed an experiment in which participants performed a continuous production task in which they memorized a visual array with colored discs, one of which was spatially retro-cued, informing the target location of an impending probe that was to be recalled (Experiment 1). We systematically varied the spatial distance between the cued and probed locations and obtained model-based estimates of the representational quality and binding strengths at varying cue-probe distances. Although the representational quality of the unattended representations remained unaffected by the cue-probe distance, spatially graded binding strengths were observed, as reflected in more spatial confusions at smaller cue-probe distances. These graded binding strengths were further replicated with a model-free approach in a categorical version of the production task in which stimuli and responses consisted of easily discriminable colors (Experiment 2). These results demonstrate that unattended representations are prone to spatial confusions due to spatial degradation of binding strengths in WM, even though they are stored with the same representational quality.

Highlights-Cancellation tasks are useful clinical tools that probe many cognitive modules-We used cancellation tests on 523 participants of different ages, sex, and education-We provide cancellation task norm scores for indices computed from a big sample-Cancellation indices include attention bias, processing speed and search organisation-About a quarter of the healthy population shows relatively disorganised searchAbstractIt is important that accurate tests exist to assess cognition in various groups of individuals. One popular test of attention and executive functioning is the cancellation task, in which participants perform multi-target visual search to find and ‘cancel’ targets among distractors. Although cancellation tasks have been used extensively with neurological patients, it is only partly clear whether performance is affected by demographic variables such as age and education, which can vary wildly among patients. Here, we describe performance in a sample of 523 healthy participants who participated in a web-based cancellation task. Specifically, we examined indices of spatial bias, processing speed, perseveration and revisiting behaviour, and search organisation. In this sample, age, sex, and level of education did not affect cancellation performance. A cluster analysis identified four cognitive profiles: Participants who make many omissions (N=18), who make many revisits (N=18), who have relatively poor search organisation (N=125), and who have relatively good search organisation (N=362). We advise neurologists and neuropsychologists to exercise caution when interpreting scores pertaining to search organisation in patients: Given the large proportion of healthy individuals with poor search organisation, disorganised search in patients might be pre-existing rather than disorder-related. Finally, we include norm scores for indices of spatial bias, perseverations and revisits, processing speed, and search organisation for a popular cancellation task.

Recent studies have shown that the pupillary light response (PLR) is modulated by higher cognitive functions, presumably through activity in visual sensory brain areas. Here we use the PLR to test the involvement of sensory areas in visual working memory (VWM). In two experiments, participants memorized either bright or dark stimuli. We found that pupils were smaller when a prestimulus cue indicated that a bright stimulus should be memorized; this reflects a covert shift of attention during encoding of items into VWM. Crucially, we obtained the same result with a poststimulus cue, which shows that internal shifts of attention within VWM affect pupil size as well. Strikingly, the effect of VWM content on pupil size was most pronounced immediately after the poststimulus cue, and then dissipated. This suggests that a shift of attention within VWM momentarily activates an "active" memory representation, but that this representation quickly transforms into a "hidden" state that does not rely on sensory areas. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Empirical evidence for the detrimental effect of safety behaviors on fear extinction is inconsistent. This fear conditioning study investigated whether the negative effects of safety behavior on extinction learning depend on whether safety behavior precludes the occurrence of threat. In two experiments, participants first underwent fear acquisition. During a subsequent extinction procedure, participants used safety behavior that precluded the occurrence of threat, safety behavior that reduced threat, or no safety behavior. Safety behavior that precluded the occurrence of threat prevented extinction learning in the first and second experiments. Additionally, in the second experiment, safety behavior that reduced threat severity did not prevent extinction for several participants but did prevent it for others. The findings suggest that safety behavior that prevents the possibility of threat prevents extinction, whereas safety behavior that reduces threat does not prevent extinction consistently.

Human workers often divide labour on the basis of individual qualities. However, contemporary work on decision-making suggests collaborators value opinions equally, even when they are unequally skilled. We investigated whether this equality bias extends to division of labour in a collaborative game that leverages inter-individual short-term memory capacity differences. Pairs were shown eight memorisable items to divide among themselves, only communicating through their computer screens that displayed who claimed which items. After this, participants recalled randomly selected claimed items. To incentive collaboration, pairs were rewarded for their combined recall accuracy. Although we hypothesised they would maximise reward by dividing items according to each individuals’ capacities, pairs divided the number of items to-be-remembered equally. Furthermore, individuals’ collaboration ratings were unaffected by capacity or performance, but instead negatively correlated with task-irrelevant variability in claimed item locations. Finally, differences in claimed item numbers correlated with inter-individual differences in conscientiousness and social apathy. Our findings suggest humans have an equality bias when dividing labour between collaborators, even if they are of unequal skill.

Humans have the ability to temporarily retain information in short-term memory. This store is highly limited, which requires individuals to be selective about what information is stored. In the classic view, objects in the environment are attentionally selected and then committed to short-term memory one-by-one. However, very few direct empirical tests of this serial encoding assumption have been conducted, despite some studies suggesting that individuals can simultaneously attend to two separate items. Here we challenge the serial assumption, and demonstrate that information from separate objects can be encoded into short-term memory in parallel. We developed models of serial and parallel encoding that describe the probabilities of items being present in short-term memory throughout the encoding process, and tested them in a whole-report design. Empirical data from four experiments in healthy individuals were fitted best by the parallel encoding model, even when items were presented unilaterally (and thus processed within one hemisphere). Our results suggest that information from several items can be attentionally selected and consequently encoded into short-term memory at the same time. These findings suggest that the popular feature integration theory needs to be reformulated to account for parallel encoding, and provides important boundaries for computational models of short-term memory.

Here we show that the pupillary light response reflects exogenous (involuntary) shifts of attention and inhibition of return. Participants fixated in the center of a display that was divided into a bright and a dark half. An exogenous cue attracted attention to the bright or dark side of the display. Initially, the pupil constricted when the bright, as compared to the dark, side of the display was cued, reflecting a shift of attention toward the exogenous cue. Crucially, this pattern reversed about 1 s after cue presentation. This later-occurring, relative dilation (when the bright side was cued) reflected disengagement from the previously attended location, analogous to the behavioral phenomenon of inhibition of return. Indeed, we observed a reliable correlation between "pupillary inhibition" and behavioral inhibition of return. Our results support the view that inhibition of return results from habituation to (or short-term depression of) visual input. We conclude that the pupillary light response is a complex eye movement that reflects how we selectively parse and interpret visual input.

Threatening stimuli are known to influence attentional and visual processes in order to prioritize selection. For example, previous research showed faster detection of threatening relative to nonthreatening stimuli. This has led to the proposal that threatening stimuli are prioritized automatically via a rapid subcortical route. However, in most studies, the threatening stimulus is always to some extent task relevant. Therefore, it is still unclear if threatening stimuli are automatically prioritized by the visual system. We used the additional singleton paradigm with task-irrelevant fear-conditioned distractors (CS+ and CS-) and indexed the time course of eye movement behavior. The results demonstrate automatic prioritization of threat. First, mean latency of saccades directed to the neutral target was increased in the presence of a threatening (CS+) relative to a nonthreatening distractor (CS-), indicating exogenous attentional capture and delayed disengagement of covert attention. Second, more error saccades were directed to the threatening than to the nonthreatening distractor, indicating a modulation of automatically driven saccades. Nevertheless, cumulative distributions of the saccade latencies showed no modulation of threat for the fastest goal-driven saccades, and threat did not affect the latency of the error saccades to the distractors. Together these results suggest that threatening stimuli are automatically prioritized in attentional and visual selection but not via faster processing. Rather, we suggest that prioritization results from an enhanced representation of the threatening stimulus in the oculomotor system, which drives attentional and visual selection. The current findings are interpreted in terms of a neurobiological model of saccade programming.

During scene viewing, saccades directed toward a recently fixated location tend to be delayed relative to saccades in other directions (“delay effect”), an effect attributable to inhibition-of-return (IOR) and/or saccadic momentum (SM). Previous work indicates this effect may be task-specific, suggesting that gaze control parameters are task-relevant and potentially affected by task-switching. Accordingly, the present study investigated task-set control of gaze behavior using the delay effect as a measure of task performance. The delay effect was measured as the effect of relative saccade direction on preceding fixation duration. Participants were cued on each trial to perform either a search, memory, or rating task. Tasks were performed either in pure-task or mixed-task blocks. This design allowed separation of switch-cost and mixing-cost. The critical result was that expression of the delay effect at 2-back locations was reversed on switch versus repeat trials such that return was delayed in repeat trials but speeded in switch trials. This difference between repeat and switch trials suggests that gaze-relevant parameters may be represented and switched as part of a task-set. Existing and new tests for dissociating IOR and SM accounts of the delay effect converged on the conclusion that the delay at 2-back locations was due to SM, and that task-switching affects SM. Additionally, the new test simultaneously replicated non-corroborating results in the literature regarding facilitation-of-return (FOR), which confirmed its existence and showed that FOR is “reversed” SM that occurs when preceding and current saccades are both directed toward the 2-back location.

Eye-tracking technology is becoming increasingly cheaper, both on the hardware and on the software front. Currently, the EyeTribe tracker is the most inexpensive commercial eye tracker in the world, at a price of $99. The low costs make it a potentially interesting resource for research, but no objective testing of its quality has been performed yet. Here the EyeTribe tracker is compared with an EyeLink 1000, a high-quality video eye tracker. Results indicate that the spatial precision and accuracy are good enough for fixation checking, point-of-regard analyses, and pupilometry. However, the low sampling rate renders the device unsuitable for testing high-accuracy saccade metrics. Additionally, open-source toolboxes for Matlab and Python, and a plug-in for OpenSesame are presented, which can be used to interface with the EyeTribe tracker.