Adult attachment anxiety is associated with night eating syndrome in UK and US-based samples: Two cross-sectional studies.

Previous research has shown that "attachment anxiety" is a robust predictor of disinhibited eating behaviours and that this relationship is underpinned by difficulties in managing emotion. Night eating syndrome (NES), a proposed eating disorder characterized by evening hyperphagia, nocturnal awakenings to eat, and morning anorexia, is also associated with eating to manage emotion. Across two studies (N = 276 & N = 486), we considered a relationship between attachment anxiety and NES. In Study 1, we hypothesised (pre-registered) that attachment anxiety would predict NES score and that this relationship would be mediated by disinhibited eating. Participants were asked to complete questionnaire measures of attachment orientation, disinhibited eating (emotional and uncontrolled eating) and NES. Our parallel mediation model confirmed a direct relationship between attachment anxiety and NES (p < .001) and showed an indirect path via both emotional (95% CI: 0.15-0.63) and uncontrolled eating (95% CI: 0.001-0.36). In Study 2, we showed that fear of negative evaluation of eating significantly mediated a reversed relationship between attachment anxiety and NES (95% CI: 0.02-0.04). Finally, across both studies we used a novel tool to assess "eating to cope". We showed a relationship with emotional eating but failed to show a robust relationship with NES. Attachment orientation may represent a potential intervention target for night eating syndrome. Future research should consider a longitudinal approach to strengthen our understanding of directionality amongst these factors.

Slowed Luminance Reaction Times in Cervical Dystonia: Disordered Superior Colliculus Processing.

BACKGROUND: Abnormal temporal discrimination in cervical dystonia is hypothesized to be attributable to disrupted processing in the superior colliculus. The fast, luminance-based, retinotectal pathway, projects to the superior colliculus; chromatic stimuli responses, by the retino-geniculo-calcarine pathway, are up to 30 ms longer. OBJECTIVES: We sought to interrogate visual processing and reaction times in patients with cervical dystonia compared with healthy controls. We hypothesized that cervical dystonia patients would have impaired reaction times to luminance based stimuli accessing the retino-tectal pathway in comparison to healthy control participants. METHODS: In 20 cervical dystonia and 20 age-matched control participants, we compared reaction times to two flashing visual stimuli: (1) a chromatic annulus and (2) a luminant, noncolored annulus. Participants pressed a joystick control when they perceived the annulus flashing. RESULTS: Reaction times in control participants were 20 ms significantly faster in the luminant condition than the chromatic (P = 0.017). Patients with cervical dystonia had no reaction time advantage in response to the luminant stimulus. CONCLUSION: Cervical dystonia patients (compared to control participants) demonstrated no reduction in their reaction time to luminant stimuli, processed through the retinotectal pathway. This finding is consistent with superior colliculus dysfunction in cervical dystonia. © 2020 International Parkinson and Movement Disorder Society.

Contributions of form, motion and task to biological motion perception.

The ability of human observers to detect 'biological motion' of humans and animals has been taken as evidence of specialized perceptual mechanisms. This ability remains unimpaired when the stimulus is reduced to a moving array of dots representing only the joints of the agent: the point light walker (PLW) (G. Johansson, 1973). Such stimuli arguably contain underlying form, and recent debate has centered on the contributions of form and motion to their processing (J. O. Garcia & E. D. Grossman, 2008; E. Hiris, 2007). Human actions contain periodic variations in form; we exploit this by using brief presentations to reveal how these natural variations affect perceptual processing. Comparing performance with static and dynamic presentations reveals the influence of integrative motion signals. Form information appears to play a critical role in biological motion processing and our results show that this information is supported, not replaced, by the integrative motion signals conveyed by the relationships between the dots of the PLW. However, our data also suggest strong task effects on the relevance of the information presented by the PLW. We discuss the relationship between task performance and stimulus in terms of form and motion information, and the implications for conclusions drawn from PLW based studies.

Effects of Changes in Background Colour on the Identification of Own- and Other-Race Faces.

The current study investigated whether small differences in the background colours between the lineup members would influence identification accuracy of own-race and other-race faces. Using the well-established 1-in-10 paradigm, half of the array faces had exactly the same backgrounds, and half were on backgrounds of slightly different hues of green. For target present arrays, participants were more accurate at identifying own-race faces when compared with the other-race faces when all backgrounds were the same. However, when backgrounds had slightly different hues, there was no difference in how accurate people were at identifying faces from both races. For target absent arrays, participants were more likely to incorrectly choose a face if the backgrounds were not all the same, regardless of the race of faces. Real-world implications from these findings are that using lineups where the backgrounds are slightly different hues may increase the likelihood of the false identification of innocent suspects.

Dissociable Effects of Tryptophan Supplementation on Negative Feedback Sensitivity and Reversal Learning.

Serotonin has been shown to modulate probabilistic reversal learning (PRL) and negative feedback sensitivity (NFS) in both animal and human studies. Whilst these two measures are tightly coupled, some studies have suggested that these may be mediated by independent mechanisms; the former, representing perseveration and cognitive flexibility, and the latter measuring the ability to maintain a response set (win-stay) at the expense of lose-shift behavior when occasional misleading feedback has been presented. Here, we tested this hypothesis in 44 healthy participants who were administered tryptophan (22 placebo, 22 tryptophan), a precursor to serotonin. We found a dissociable effect of tryptophan supplementation on PRL/NFS. Specifically, tryptophan administration increased NFS compared to the placebo group but had no effect on PRL. We discuss these findings in relation to dosages and with a particular focus on the acute tryptophan depletion (ATD) procedures.

Internet-based measurement of visual assessment skill of trainee radiologists: developing a sensitive tool.

OBJECTIVE: Expert radiologists exhibit high levels of visual diagnostic accuracy from review of radiological images, doing so after accumulating years of training and experience. To train new radiologists, learning interventions must focus on the development of these skills. By developing a web-based measure of image assessment, a key part of visual diagnosis, we aimed to capture differences in the performance of expert, trainee and non-radiologists. METHODS: 12 consultant paediatric radiologists, 12 radiology registrars, and 39 medical students were recruited to the study. All participants completed a two-part, online task requiring them to visually assess 30 images (25 containing an abnormality) drawn from a library of 150 paediatric skeletal radiographs assessed prior to the study. Participants first identified whether an image contained an abnormality, and then clicked within the image to mark its location. Performance measures of identification accuracy, localisation precision, and task time were collected. RESULTS: Despite the difficulties of web-based testing, large differences in performance, both in terms of the accuracy of abnormality identification and in the precision of abnormality localisation were found between groups, with consultant radiologists the most accurate both at identifying images containing abnormalities (p < 0.001) and at localising abnormalities on the images (p < 0.001). CONCLUSIONS: Our data demonstrate that an online measurement of radiological skill is sufficiently sensitive to detect group level changes in performance consistent with the development of expertise. ADVANCES IN KNOWLEDGE: The developed tool will allow future studies assessing the impact of different training strategies on cognitive performance and diagnostic accuracy.

A Mobile App Delivering a Gamified Battery of Cognitive Tests Designed for Repeated Play (OU Brainwave): App Design and Cohort Study.

BACKGROUND: Mobile phone and tablet apps are an increasingly common platform for collecting data. A key challenge for researchers has been participant "buy-in" and attrition for designs requiring repeated testing. OBJECTIVE: The objective of this study was to develop and assess the utility of 1-2 minute versions of both classic and novel cognitive tasks using a user-focused and user-driven mobile phone and tablet app designed to encourage repeated play. METHODS: A large sample of app users (N=13,979 at first data collection) participated in multiple, self-paced sessions of classic working memory (N-back), spatial cognition (mental rotation), sustained attentional focus (persistent vigilance task), and split attention (multiple object tracking) tasks, along with the implementation of a comparatively novel action-learning task. The "OU Brainwave" app was designed to measure time-of-day variation in cognitive performance and did not offer any training program or promise any cognitive enhancement. To record participants' chronotype, a full Morningness-Eveningness questionnaire was also included, which measures whether a person's circadian rhythm produces peak alertness in the morning, in the evening, or in between. Data were collected during an 18-month period. While the app prompted re-engagement at set intervals, participants were free to complete each task as many times as they wished. RESULTS: We found a significant relationship between morningness and age (r=.298, n=12,755, P<.001), with no effect of gender (t13,539=-1.036, P=.30). We report good task adherence, with ~4000 participants repeatedly playing each game >4 times each-our minimum engagement level for analysis. Repeated plays of these games allowed us to replicate commonly reported gender effects in gamified spatial cognition (F1,4216=154.861, P<.001, η2ρ=.035), split attention (F1,4185=11.047, P=.001, η2ρ=.003), and sustained attentional focus (F1,4238=15.993, P<.001, η2ρ=.004) tasks. We also report evidence of a small gender effect in an action-learning task (F1,3988=90.59, P<.001, η2ρ=.022). Finally, we found a strong negative effect of self-reported age on performance, when controlling for number of plays, in sustained attentional focus (n=1596, F6,1595=30.23, P<.001, η2=.102), working memory (n=1627, F6,1626=19.78, P<.001, η2=.068), spatial cognition (n=1640, F6,1639=23.74, P<.001, η2=.080), and split attention tasks (n=1616, F6,1615=2.48, P=.02, η2=.009). CONCLUSIONS: Using extremely short testing periods and permitting participants to decide their level of engagement-both in terms of which gamified task they played and how many sessions they completed-we were able to collect a substantial and valid dataset. We suggest that the success of OU Brainwave should inform future research oriented apps-particularly in issues of balancing participant engagement with data fidelity.

Biological movement and the encoding of its motion and orientation.

Are you walking at me? Biological movement and the encoding of its motion and orientation. A person's motion conveys a wealth of information that ranges from the complex, such as intention or emotional state, to the simple, such as direction of locomotion. How we recognise and recover people's motion is addressed by models of biological motion processing. Single channel models propose that this occurs through the operation of form template neurons which respond to viewpoint dependent snapshots of posture. More controversially, a dual channel approach proposes a second stream containing motion template neurons sensitive to view dependent snapshots of biological movement's characteristic local velocity field. We used behavioural adaptation to look for the co-encoding of viewpoint and walker motion, a hallmark of motion template analysis. We show that opposite viewpoint aftereffects can simultaneously be induced for forwards and reversed walkers. This demonstrates that distinct populations of neurons encode forwards and reversed walking. To account for such aftereffects, these units must either be able to inhibit viewpoint-encoding neurons, or they must encode viewpoint directly. Whereas current single channel models would need extending to incorporate these characteristics, the idea that walker motion is encoded directly, such that viewpoint and motion are intrinsically interlinked, is a fundamental component of the dual channel model.

No learning where to go without first knowing where you're coming from: action discovery is trajectory, not endpoint based.

Intrinsic motivations drive an agent to explore, providing essential data for linking behaviors with novel outcomes and so laying the foundation for future flexible action. We present experiments using a new behavioral task which allows us to interrogate the connection between exploration and action learning. Human participants used a joystick to search repeatedly for a target location, only receiving feedback on successful discovery. Feedback delay was manipulated, as was the starting position. Experiment 1 employed stable starting positions, so the task could be learnt with respect to a target location or a target trajectory. Participants were able to learn the correct movement under all delay conditions. Experiment 2 used a variable starting location, so the correct movement could only be learnt in terms of target location. Participants displayed little to no learning in this experiment. These results suggest that movements on this scale are stored as trajectories rather than in terms of target location. Overall the experiments demonstrate the potential of this task for uncovering the native representational substrates of action learning.

The path to learning: action acquisition is impaired when visual reinforcement signals must first access cortex.

Animals, interacting with the environment, learn and exploit the consequences of their movements. Fundamental to this is the pairing of salient sensory input with recent motor output to form an action-outcome pair linking a performed movement with its outcome. Short-latency dopamine (DA) signalling in the basal ganglia has been proposed to support this crucial task. For visual stimuli, this DA signalling is triggered at short latency by input from the superior colliculus (SC). While some aspects of the visual signal (e.g. luminance), are relayed directly to the SC via the retinotectal projection, other information unavailable to this subcortical pathway must take a more circuitous route to the SC, first submitting to early visual processing in cortex. By comparing action-outcome pairing when the visual stimulus denoting success was immediately available to the SC, via the retinotectal pathway, against that when cortical processing of the signal was required, the impact this additional sensory processing has on action-outcome learning can be established. We found that action acquisition was significantly impaired when the action was reinforced by a stimulus ineligible for the retinotectal pathway. Furthermore, we found that when the stimulus was eligible for the retinotectal pathway but evoked an increased latency, action acquisition was not impaired. These results suggest that the afferent sensory pathway via the SC is certainly primary and possibly instrumental to the DA neurons' role in the discovery of novel actions and that the differences found are not due to simple sensory latency.

The discovery of novel actions is affected by very brief reinforcement delays and reinforcement modality.

ABSTRACT The authors investigated the ability of human participants to discover novel actions under conditions of delayed reinforcement. Participants used a joystick to search for a target indicated by visual or auditory reinforcement. Reinforcement delays of 75-150 ms were found to significantly impair action acquisition. They also found an effect of modality, with acquisition superior with auditory feedback. The duration at which delay was found to impede action discovery is, to the authors' knowledge, shorter than that previously reported from work with operant and causal learning paradigms. The sensitivity to delay reported, and the difference between modalities, is consistent with accounts of action discovery that emphasize the importance of a time stamp in the motor record for solving the credit assignment problem.

A novel task for the investigation of action acquisition.

We present a behavioural task designed for the investigation of how novel instrumental actions are discovered and learnt. The task consists of free movement with a manipulandum, during which the full range of possible movements can be explored by the participant and recorded. A subset of these movements, the 'target', is set to trigger a reinforcing signal. The task is to discover what movements of the manipulandum evoke the reinforcement signal. Targets can be defined in spatial, temporal, or kinematic terms, can be a combination of these aspects, or can represent the concatenation of actions into a larger gesture. The task allows the study of how the specific elements of behaviour which cause the reinforcing signal are identified, refined and stored by the participant. The task provides a paradigm where the exploratory motive drives learning and as such we view it as in the tradition of Thorndike [1]. Most importantly it allows for repeated measures, since when a novel action is acquired the criterion for triggering reinforcement can be changed requiring a new action to be discovered. Here, we present data using both humans and rats as subjects, showing that our task is easily scalable in difficulty, adaptable across species, and produces a rich set of behavioural measures offering new and valuable insight into the action learning process.