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The self-concept—defined as the cognitive representation of beliefs about oneself—determines how individuals view themselves, others, and their actions. A negative self-concept can drive gaming use and internet gaming disorder (IGD). The assessment of the neural correlates of self-evaluation gained popularity to assess the self-concept in individuals with IGD. This attempt, however, seems to critically depend on the reliability of the investigated task-fMRI brain activation. As first study to date, we assessed test–retest reliability of an fMRI self-evaluation task. Test–retest reliability of neural brain activation between two separate fMRI sessions (approximately 12 months apart) was investigated in N = 29 healthy participants and N = 11 individuals with pathological internet gaming. We computed reliability estimates for the different task contrasts (self, a familiar, and an unknown person) and the contrast (self > familiar and unknown person). Data indicated good test–retest reliability of brain activation, captured by the “self”, “familiar person”, and “unknown person” contrasts, in a large network of brain regions in the whole sample (N = 40) and when considering both experimental groups separately. In contrast to that, only a small set of brain regions showed moderate to good reliability, when investigating the contrasts (“self > familiar and unknown person”). The lower reliability of the contrast can be attributed to the fact that the constituting contrast conditions were highly correlated. Future research on self-evaluation should be cautioned by the findings of substantial local reliability differences across the brain and employ methods to overcome these limitations.

Die reliable und valide Diagnostik und Therapie bipolarer Storungen und affektiver Episoden unterliegen im klinischen Alltag umfanglichen, insbesondere auch methodischen Limitierungen. Nutzen von Smartphones und mobiler Sensorik fur verbesserte Diagnostik und Therapie bei bipolaren Storungen. Kritische Diskussion der aktuellen Forschungslage zum Einsatz ambulanten Assessments und digitaler Phanotypisierung bei bipolaren Storungen. Beobachtungszeitraume sowie eingesetzte Sensorik sind in vielen Studien noch zu kurz bzw. zu ungenau, um Verhaltensanderungen im Kontext affektiver Episoden reliabel und valide erfassen zu konnen. Die Prazisierung und Operationalisierung von psychopathologischen Konstrukten im Sinne einer Messbarmachung objektiv beobachtbarer und erfassbarer Verhaltensanderungen im Rahmen bipolarer Erkrankungen ist bei der Diagnostik und Therapie bipolarer Storungen fur den erfolgreichen Einsatz moderner mobiler Technologien essenziell.

Background and aims Internet gaming addiction appears to be related to self-concept deficits and increased angular gyrus (AG)-related identification with one's avatar. For increased social network use, a few existing studies suggest striatal-related positive social feedback as an underlying factor. However, whether an impaired self-concept and its reward-based compensation through the online presentation of an idealized version of the self are related to pathological social network use has not been investigated yet. We aimed to compare different stages of pathological Internet game and social network use to explore the neural basis of avatar and self-identification in addictive use. Methods About 19 pathological Internet gamers, 19 pathological social network users, and 19 healthy controls underwent functional magnetic resonance imaging while completing a self-retrieval paradigm, asking participants to rate the degree to which various self-concept-related characteristics described their self, ideal, and avatar. Self-concept-related characteristics were also psychometrically assessed. Results Psychometric testing indicated that pathological Internet gamers exhibited higher self-concept deficits generally, whereas pathological social network users exhibit deficits in emotion regulation only. We observed left AG hyperactivations in Internet gamers during avatar reflection and a correlation with symptom severity. Striatal hypoactivations during self-reflection (vs. ideal reflection) were observed in social network users and were correlated with symptom severity. Discussion and conclusion Internet gaming addiction appears to be linked to increased identification with one's avatar, evidenced by high left AG activations in pathological Internet gamers. Addiction to social networks seems to be characterized by emotion regulation deficits, reflected by reduced striatal activation during self-reflection compared to during ideal reflection.

Accelerometers offer opportunities for researchers to capture validdata about the intensity and amount of physical behavior (PB) in real-time over a period of several days and weeks. From this multi-dimensional data, a great number of metrics can be derived to captureand describe the unique aspects of PB. The goal of this paper is to helpthe end-user of PB monitoring devices (novice to intermediate experi-ence) wade through sometimes excessive technical details of accel-erometry to outline best practices in selecting and applying devices toquantify three major behavioral categories of common interest to theresearch community: physical activity (PA), sedentary behavior (SB)and sleep. The effects of these decisions on the metrics (energy ex-penditure, activity intensity, body position, activity patterns) can occurin a variety of ways. The device, carrying position (hip, wrist, thigh)and recording parameters (epoch length (EL), frequency, memory ca-pacity, recording frequency andfilters) have a large influence on themeasured activity. The different backgrounds such as study design(purpose, repeated measurements) and duration (time frame, weartime) as well as data storage and evaluation must be taken into accountwhen determining the parameters. Finally, the evaluation must adjustseveral levers (raw data, context information, non-wear time, intensityclassification, compliance) depending on the target variables. Lookinginto the future, current developments in statistical analysis are dis-cussed, because the research community has not yet reached a con-sensus on the most promising approach. There are exciting develop-ments ahead of us in the future. Sleep in particular is increasingly beingseen as an influencing factor for health. Together with the technicaldevelopments in sensors which will become incrementally smaller,more accurate and in the near future will be integrated directly into ourclothes or skin, accelerometry is facing exciting times and lots of data toevaluate.

The present study investigated changes in frontal and parietal activity related to visuomotor learning. Improvement in task performance should be achieved by a transition from feedback control to feedforward control. Event-related potential (ERP) activity related to visual feedback analysis of successful error corrections was expected to decrease at parietal scalp locations. (Pre-) motor activity related to the execution of directional changes should increase and begin earlier. While using a mouse or a joystick for cursor control, subjects performed four different conditions of a pursuit tracking task in a between-subject design. To increase task difficulty, and to set up an implicit learning condition, the gain between mouse/joystick movement and cursor movement increased during the middle of each tracking trial. Subjects were informed about this manipulation in the explicit task only. Within the continuous movement of 12 s duration, ERPs were assigned to phasic changes of target and cursor direction. Visuomotor learning was mainly achieved by a continuous reduction of target and cursor distance. A fronto-central positive ERP component related to the execution of a directional change increased earlier after learning. This indicates an anticipated directional change, improving task performance. ERP activity after error corrections decreased after learning, indicating either a higher efficiency or a reduced demand in visual feedback control. Activity difference was shifted from parietal to fronto-central sites later indicating a relation to improved feedforward control. No clear difference between implicit and explicit learning was observed for behavioural and ERP data.

Unter Akupunktur wurden bislang verschiedene neurophysiologische Effekte beobachtet. Bislang gibt es noch keine Studie, in der die Korrelation von zentralnervosen Veranderungen mit vegetativen Effekten placebokontrolliert untersucht wurde. Unter Berucksichtigung einer verlasslichen Verblindung der Probanden war Ziel dieser Studie, spezifische zerebrale und vegetative Effekte von Verum-Akupunktur (VA) am Akupunkturpunkt Di 4 (Hegu) im Vergleich zu Placebo-Akupunktur (PA) zu untersuchen. Gesunde Probanden erhielten beidseits entweder Akupunktur an Di 4 mit einer Verum-Nadel oder Akupunktur an einem Nicht-Akupunkturpunkt mit einer Placebo-Nadel. Parallel dazu wurden EEG und EKG abgeleitet. Es folgte eine Befragung zu Schmerzen, Hautdurchstich und vegetativen Effekten. Das Gefuhl des Hautdurchstichs war nicht signifikant unterschiedlich (p = 0,057). Vegetative Effekte und De Qi-Gefuhl traten jedoch signifikant haufiger bei VA auf (p = 0,022). Das Schmerzempfinden war bei VA-Stimulation erhoht gegenuber PA (p < 0,01). Die Verum-Stimulation fuhrte zu einer Erhohung der okzipitalen EEG-Alpha-Power (p < 0,03). Der Anstieg der Alpha 1-Wellen war begleitet von einem Absinken der Theta-Wellen. Der Alpha 1/Theta-Quotient verschob sich zugunsten von Alpha 1 (p < 0,04). Parallel dazu kam es zu einem kurzfristigen Anstieg des EKG-Quotienten zwischen Low-Frequency (LF) und High-Frequency (HF) (p < 0,02), gefolgt von einer Erhohung der HF-Power (p < 0,04). PA ist fur die Probanden nicht von VA unterscheidbar. Die wahrend VA-Stimulation gemessenen Veranderungen im EEG und EKG geben Hinweise auf eine Modulation der zerebralen Funktionen durch vegetative Akupunktureffekte im Unterschied zu PA.

The aim of this study was to examine whether serum anticholinergic activity (SAA) is a reliable indicator of delirium in the ICU, and whether there is a significant correlation between SAA and quantitative electroencephalographic (EEG) data in delirious patients. In a prospective cohort study, we assessed ICU patients diagnosed with delirium (n = 37). EEG measurements and blood analysis including SAA were performed 48 h following ICU admission. The presence of delirium was evaluated using the Confusion Assessment Method for critically ill patients in ICU (CAM-ICU). The SAA level was measured using a competitive radioreceptor binding assay for muscarinergic receptors and quantitative EEG was measured using the CATEEM system. We found that, under comparable conditions, patients in the delirium group showed a higher relative EEG theta power and a reduced alpha power (n = 17) than did the non-delirious patients (n = 20). No difference in measured SAA levels were seen; therefore, there was no correlation between SAA and EEG measurements in delirious patients. We conclude that, in contrast to the EEG, the SAA level cannot be proposed as a tool for diagnosing delirium in ICU patients.

Semantic network models propose that automatic (e.g. spreading activation) and controlled processes are involved in semantic priming. Behavioural studies propose that the influence of each of these processes depends on the stimulus onset asynchrony (SOA). To investigate this hypothesis with a more sensitive method, we applied high-resolution event-related potential (ERP) measures to a word-pseudoword lexical decision task that contained direct, indirect, and non-related prime-target pairs. SOAs consisted of 150 or 700 ms. The results showed that independently of SOA, increasing semantic distance prolonged reaction times and enlarged N400 amplitudes. Furthermore, the word-pseudoword decision evoked a parieto-central late positive complex (LPC respectively delayed P300), which was sensitive for semantic relatedness in the short SOA only. In addition, we found two early frontal components: a P250 in the short SOA only and a N310 sensitive to semantic relatedness more prominent in the short SOA. We conclude that ERP-differences between both SOAs indicate two separate processes: (1) an access to semantic memory, which is facilitated by spreading activation in the short SOA only; and (2) an SOA-independent, controlled process, which integrates prime and target words into a semantic context.

BackgroundInternet gaming disorder appears to be associated with self-concept deficits and increased identification with one's avatar. For increased social network use, the few existing studies suggest striatal-related positive social feedback as an underlying factor. Furthermore, few study findings indicate that internet addicts generally have problems in emotional inhibitory control processing.MethodsPathological and addicted internet gamers as well as social network users were compared with healthy controls regarding psychometric and neurobiological measures of self-concept-related characteristics, avatar identification and emotional inhibitory control processing.Results and conclusionPsychometric results indicated that both subgroups showed higher self-concept deficits compared to healthy controls. Neurobiologically, different brain activation patterns were observed in the subgroups during self-knowledge retrieval and inhibition of emotional stimuli. Furthermore, addicted internet gamers showed a higher identification with the own avatar, mirrored in an increased left angular gyrus activation, a region functionally associated with identification processing and feelings of empathy.These findings provide a starting point for the deduction of specific psychotherapeutic treatment approaches for addicted internet gamers and social network users.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Light therapy (LT) is regarded as the treatment of choice for seasonal affective disorder (SAD). In nonseasonal depression the results of light therapy are nonconclusive. Sleep deprivation (SD), however, is effective in 50-60% of the patients with major depression. The predictive value of Total Sleep Deprivation (TSD) for the treatment outcome of antidepressiva has been already examined. Purpose of the present study was to test whether light therapy is more beneficial in TSD responders than in TSD nonresponders. 40 inpatients with major depressive disorder completed one night of TSD. Twenty TSD responders and 20 TSD nonresponders were randomly assigned to 14 days of bright light therapy (2500 lux, 7-9 a.m.) or 14 days of dim light therapy (red light 50 lux, 7-9 a.m.). Manova with repeated measurements revealed a significant difference in the course of depression over the time between TSD responders and nonresponders, but no significant difference between bright and dim light. Questions of placebo effect, of SAD and of personality variables as predictors of response to SD and LT are being discussed.

A novel ERP paradigm was employed to investigate conceptual expansion, a central component of creative thinking. Participants were presented with word pairs, consisting of everyday objects and uses for these objects, which had to be judged based on the two defining criteria of creative products: unusualness and appropriateness. Three subject-determined trial types resulted from this judgement: high unusual and low appropriate (nonsensical uses), low unusual and high appropriate (common uses), and high unusual and high appropriate (creative uses). Word pairs of the creative uses type are held to passively induce conceptual expansion. The N400 component was not specifically modulated by conceptual expansion but was, instead, generally responsive as a function of unusualness or novelty of the stimuli (nonsense=creative>common). Explorative analyses in a later time window (500–900 ms) revealed that ERP activity in this phase indexes appropriateness (nonsense>creative=common). In the discussion of these findings with reference to the literature on semantic cognition, both components are proposed as indexing processes relevant to conceptual expansion as they are selectively involved in the encoding and integration of a newly established semantic connection between two previously unrelated concepts.

Based on a previous exploratory study, the functionality of event-related potentials related to visuomotor processing and learning was investigated. Three pursuit tracking tasks (cursor control either mouse, joystick, or bimanually) revealed the greatest tracking error and greatest learning effect in the bimanual task. The smallest error without learning was found in the mouse task. Error reduction reflected visuomotor learning. In detail, target-cursor distance was reduced continuously, indicating a better fit to a changed direction, whereas response time remained at 300 ms. A central positive ERP component with an activity onset 100 ms after a directional change of the target and most likely generated in premotor areas could be assigned to response planning and execution. The magnitude of this component was modulated by within-and-between-task difficulty and size of the tracking error. Most importantly, the size of this component was sensitive to between-subject performance and increased with visuomotor learning.

The aim of this single-blind randomized crossover study was to evaluate specific effects of manual acupuncture on central and vegetative nervous system activity measured by quantitative electroencephalography (qEEG) and heart rate variability (HRV).Twenty (20) healthy volunteers (mean: 25.2 +/- 3.6 years) were monitored simultaneously using a qEEG system and a 12-channel electrocardiogram recorder during verum acupuncture (VA) at acupuncture point Large Intestine 4 (Hegu) (LI4) or placebo acupuncture (PA) at a sham point.In the EEG conduction of the occipital area, needle stimulation in VA increased alpha1-frequency significantly, and the ratio alpha1/theta was shifted to the benefit of alpha1 over all electrodes. The HRV parameters showed a significant increase of the low frequency/high frequency (HF) ratio during the first minute of stimulation in VA, indicating an initial increase of sympathetic activation. However, an increase of HF power in the minute after stimulation followed by a decrease in heart rate suggests delayed vagal activation. De qi (a sensation that is typical of acupuncture needling) occurred in 16 subjects during VA and in 9 volunteers during PA (80% versus 45%).Manual stimulation on LI4 seems to lead to specific changes in alpha EEG-frequency and in HRV parameters. A linear relationship between the HRV parameters and the alpha EEG band might point to a specific modulation of cerebral function by vegetative effects during acupuncture.