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 to collect data. A key challenge for researchers has been participant “buy-in” and participant attrition for designs requiring repeated testing. Objective: The objective of this study was to develop and asses the utility of 1 – 2 minute versions of both classic and novel cognitive tasks within a user focussed and driven mobile phone and tablet app designed to encourage repeated play. Methods: A large sample (N = 13,979 at first data collection) participated in multiple, self-paced, sessions of working memory (N-back), spatial cognition (Mental rotation), sustained attentional focus (Persistent Vigilance task), and split attention (Multiple object tracking) tasks along with an implementation of a novel action learning task. A full morningness-eveningness questionnaire was also included. Data was collected across an 18 month period. While the app prompted reengagement at set intervals, each participant was free to repeatedly complete each task as many times as they wished. Results: We found a significant relationship between morningness and age (r = 0.298, n = 12755, p Conclusions: Using extremely short testing periods and permitting participants to decide their own 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 around balancing participant engagement with data fidelity

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 TP arrays, participants were more accurate at identifying own-race faces, as compared to 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 TA 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

No contribution of object category information in perceptual thresholds : evidence from Candy Crush

An emerging view in visual learning is that the rewards associated with particular visual stimuli lead to enhanced early sensory representations. However, it is unclear whether object category information is required for reward-related facilitation of early sensory representations, or whether any facilitation occurs at a more fundamental level. Video games which rely on in-game icons of rewarding or neutral value offer an excellent arena in which to investigate the development of any changes in representation. To test these alternative explanations, we compared the ability of 33 Candy Crush players against 32 nonplayers to detect icons which had rewarding or neutral roles within the game. Using diffeomorphic scrambling to preserve the basic visual properties, the threshold for detection of a rewarding icon, a neutral icon and a control pair of nongame icons within a 7x7 grid of distractor icons was measured. Each participant’s thresholds were measured in a two-alternative forced choice staircase procedure. Both players and nonplayers were significantly better at detecting the rewarding in-game icon than the neutral icon and all participants showed similar reductions in threshold for the reward-associated control icon compared to the neutral control icon. Even though our most practiced players had accumulated years of experience, there was no association between playing time and perceptual thresholds. Our results suggest that there is a strong contribution of the basic visual features to performance levels both with the Candy Crush and control targets, and provide no evidence that even long experience with reward association heightens perceptual sensitivity independent of object category information

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

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: Twelve consultant paediatric radiologists, twelve radiology registrars, and thirty-nine 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

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 behaviour 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 presynaptic 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 presynaptic and postsynaptic mechanisms, receptor specificity, and dosage and with a particular focus on the acute tryptophan depletion (ATD) procedures

Empirical experiments on intrinsic motivations and action acquisition: results, evaluation, and redefinition

This document presents Deliverable D3.2 of the EU-funded Integrated Project "IM-CLeVeR - Intrinsically Motivated Cumulative Learning Versatile Robots", contract n. FP7-ICT-IP-231722.The aims of the deliverable, as given in the original IM-CLEVER proposal were to identify new key empirical phenomena and processes, allowing the design of a second set of experiments. This report covers: (1) novelty detection and discovery of when/what/how of agency in experiments with humans ("joystick experiment") and Parkinson patients. (2) how object properties that stimulate intrinsically motivated interaction and facilitate the acquisition of adaptive knowledge and skills in monkeys and children ("board experiment")

Slowed luminance reaction times in cervical dystonia: disordered superior colliculus processing

Background: Abnormal temporal discrimination in cervical dystonia is hypothesised to be due to disrupted processing in the superior colliculus. The fast, luminance-based, retino-tectal pathway, projects to the superior colliculus; chromatic stimuli responses, via the retino-geniculo-calcarine pathway, are up to 30ms longer. Methods: In 20 cervical dystonia and 20 age-matched control participants, we compared reaction times to two flashing visual stimuli: (i) a chromatic annulus and (ii) a luminant, non-coloured annulus. Participants pressed a joystick control when they perceived the annulus flashing. Results: Reaction times in control participants were 20ms 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 retino-tectal pathway. This finding is consistent with superior colliculus dysfunction in cervical dystonia