Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We have therefore conducted a meta-analysis that analyzes the effects of characteristics of digital game stressors and study design on heart rate, systolic and diastolic blood pressure, in studies carried out from 1976 to 2012. In order to assess the differing quality between study designs, a new scale is developed and presented, coined reliability of effect size. The results show specific and consistent moderating functions of both game and study characteristics, on average accounting for around 43%, and in certain cases up to 57% of the variance found in physiological stress responses. Possible cognitive and physiological processes underlying these moderating functions are discussed, and a new model integrating these processes with the moderating functions is presented. These findings indicate that a digital game stressor does not act as a stressor by virtue of being a game, but rather derives its stressor function from its characteristics and the methodology in which it is used. This finding, together with the size of the associated moderations, indicates the need for a standardization of digital game stressors.

Objective Knowledge on gut–brain interaction might help to develop new therapies for patients with anorexia nervosa (AN), as severe starvation‐induced changes of the microbiome (MI) do not normalise with weight gain. We examine the effects of probiotics supplementation on the gut MI in patients with AN. Method This is a study protocol for a two‐centre double‐blind randomized‐controlled trial comparing the clinical efficacy of multistrain probiotic administration in addition to treatment‐as‐usual compared to placebo in 60 patients with AN (13–19 years). Moreover, 60 sex‐ and age‐matched healthy controls are included in order to record development‐related changes. Assessments are conducted at baseline, discharge, 6 and 12 months after baseline. Assessments include measures of body mass index, psychopathology (including eating‐disorder‐related psychopathology, depression and anxiety), neuropsychological measures, serum and stool analyses. We hypothesise that probiotic administration will have positive effects on the gut microbiota and the treatment of AN by improvement of weight gain, gastrointestinal complaints and psychopathology, and reduction of inflammatory processes compared to placebo. Conclusions If probiotics could help to normalise the MI composition, reduce inflammation and gastrointestinal discomfort and increase body weight, its administration would be a readily applicable additional component of multi‐modal AN treatment.

The objective of this study was to test the feasibility of using the dorsolateral prefrontal cortex as a signal source for brain–computer interface control in people with severe motor impairment. We implanted two individuals with locked-in syndrome with a chronic brain–computer interface designed to restore independent communication. The implanted system (Utrecht NeuroProsthesis) included electrode strips placed subdurally over the dorsolateral prefrontal cortex. In both participants, counting backwards activated the dorsolateral prefrontal cortex consistently over the course of 47 and 22 months, respectively. Moreover, both participants were able to use this signal to control a cursor in one dimension, with average accuracy scores of 78 ± 9% (standard deviation) and 71 ± 11% (chance level: 50%), respectively. Brain–computer interface control based on dorsolateral prefrontal cortex activity is feasible in people with locked-in syndrome and may become of relevance for those unable to use sensorimotor signals for control.

In a multitude of research and therapy paradigms it is relevant to know, and desirably to control, the stress state of a patient or participant. Examples include research paradigms in which the stress state is the dependent or independent variable, or therapy paradigms where this state indicates the boundaries of the therapy. To our knowledge, no application currently exists that focuses specifically on the automated control of the stress state while at the same time being generic enough to be used in various therapy and research purposes. Therefore, we introduce GASICA, an application aimed at the automated control of the stress state in a multitude of therapy and research paradigms. The application consists of three components: a digital stressor game, a set of measurement devices, and a feedback model. These three components form a closed loop (called a biocybernetic loop by Pope et al. (1995) and Fairclough (2009) that continuously presents an acute psychological stressor, measures several physiological responses to this stressor, and adjusts the stressor intensity based on these measurements by means of the feedback model, hereby aiming to control the stress state. In this manner GASICA presents multidimensional and ecological valid stressors, whilst continuously in control of the form and intensity of the presented stressors, aiming at the automated control of the stress state. Furthermore, the application is designed as a modular open-source application to easily implement different therapy and research tasks using a high-level programming interface and configuration file, and allows for the addition of (existing) measurement equipment, making it usable for various paradigms.

Background Anorexia nervosa (AN) is a severe psychiatric disease that often takes a chronic course due to insufficient treatment options. Emerging evidence on the gut-brain axis offers the opportunity to find innovative treatments for patients with psychiatric disorders. The gut microbiome of patients with AN shows profound alterations that do not completely disappear after weight rehabilitation. In previous studies, the administration of polyunsaturated fatty acids (PUFA) resulted in effects that might be beneficial in the treatment of AN, affecting the microbiome, body weight and executive functions. Therefore, the MiGBAN study aims to examine the effects of a nutritional supplementation with PUFA on the gut microbiome and body mass index (BMI) in patients with AN. Methods This is a longitudinal, double-blind, randomized, placebo-controlled trial. Within 2 years, 60 adolescent patients aged 12 to 19 years with AN will receive either PUFA or placebo for 6 months additional to treatment as usual. After 1 year, the long-term effect of PUFA on the gut microbiome and consecutively on BMI will be determined. Secondary outcomes include improvement of gastrointestinal symptoms, eating disorder psychopathology, and comorbidities. Additionally, the interaction of the gut microbiome with the brain (microbiome-gut-brain axis) will be studied by conducting MRI measurements to assess functional and morphological changes and neuropsychological assessments to describe cognitive functioning. Anti-inflammatory effects of PUFA in AN will be examined via serum inflammation and gut permeability markers. Our hypothesis is that PUFA administration will have positive effects on the gut microbiota and thus the treatment of AN by leading to a faster weight gain and a reduction of gastrointestinal problems and eating disorder psychopathology. Discussion Due to previously heterogeneous results, a systematic and longitudinal investigation of the microbiome-gut-brain axis in AN is essential. The current trial aims to further analyse this promising research field to identify new, effective therapeutic tools that could help improve the treatment and quality of life of patients. If this trial is successful and PUFA supplementation contributes to beneficial microbiome changes and a better treatment outcome, their administration would be a readily applicable additional component of multimodal AN treatment. Trial registration German Clinical Trials Register DRKS00017130. Registered on 12 November 2019.