Neural and behavioral adaptations to frontal theta neurofeedback training: A proof of concept study.

Previous neurofeedback research has shown training-related frontal theta increases and performance improvements on some executive tasks in real feedback versus sham control groups. However, typical sham control groups receive false or non-contingent feedback, making it difficult to know whether observed differences between groups are associated with accurate contingent feedback or other cognitive mechanisms (motivation, control strategies, attentional engagement, fatigue, etc.). To address this question, we investigated differences between two frontal theta training groups, each receiving accurate contingent feedback, but with different top-down goals: (1) increase and (2) alternate increase/decrease. We hypothesized that the increase group would exhibit greater increases in frontal theta compared to the alternate group, which would exhibit lower frontal theta during down- versus up-modulation blocks over sessions. We also hypothesized that the alternate group would exhibit greater performance improvements on a Go-NoGo shooting task requiring alterations in behavioral activation and inhibition, as the alternate group would be trained with greater task specificity, suggesting that receiving accurate contingent feedback may be the more salient learning mechanism underlying frontal theta neurofeedback training gains. Thirty young healthy volunteers were randomly assigned to increase or alternate groups. Training consisted of an orientation session, five neurofeedback training sessions (six blocks of six 30-s trials of FCz theta modulation (4-7 Hz) separated by 10-s rest intervals), and six Go-NoGo testing sessions (four blocks of 90 trials in both Low and High time-stress conditions). Multilevel modeling revealed greater frontal theta increases in the alternate group over training sessions. Further, Go-NoGo task performance increased at a greater rate in the increase group (accuracy and reaction time, but not commission errors). Overall, these results reject our hypotheses and suggest that changes in frontal theta and performance outcomes were not explained by reinforcement learning afforded by accurate contingent feedback. We discuss our findings in terms of alternative conceptual and methodological considerations, as well as limitations of this research.

Using a frequentist and Bayesian approach to examine video game usage, substance use, and sleep among college students.

Video games are a popular form of entertainment. However, there is mixed evidence for the association between video game usage and poor sleep quality, short sleep duration, or delayed sleep timing. The current study examined associations between daily sleep behaviours and video game usage via a Bayesian and frequentist statistical approach. Caffeine and alcohol consumption were also assessed as moderators, as these behaviours may co-occur with video game usage and poor sleep. 1032 (72% female) undergraduate students were recruited between 2006-2007. Participants completed questionnaires examining video game and substance use, as well as sleep diaries for 1 week. Frequentist analyses revealed that video game usage was related to increased variability in the total sleep time, and a later average sleep midpoint, but not sleep efficiency. Alcohol use moderated the relationships between video game usage and both average and variability in total sleep time. Caffeine use was related to shorter average total sleep time and more variability in sleep efficiency. Alcohol consumption was related to more variability in the total sleep time and sleep midpoint, and a later average sleep midpoint. Bayesian models suggested strong evidence that video game playing was associated with later average sleep midpoint. Like the frequentist approach, alcohol consumption moderated the relationship between video game usage and both average and variability in total sleep time, but the evidence was weak. The effect sizes for both approaches tended to be small. Using a rigorous statistical approach and a large sample, this study provides robust evidence that video game usage may not be strongly associated with poor sleep among undergraduate students.

Factor analysis of the virtual reality Stroop task.

INTRODUCTION: Virtual reality (VR) offers neuropsychologists high dimensional (3D) platforms for administering cognitive tasks that balance experimental control with simulations of naturalistic activities. A virtual reality version of the Stroop task, the Virtual Reality Stroop Task (VRST), was developed that leverages technological advances to enhance the ecological validity of neuropsychological assessments. The high mobility multipurpose wheeled vehicle (HMMWV) version of the VRST includes high arousal (ambush) and low arousal (safe) zones was employed in this study. This version of the VRST contains both cognitive (Stroop) and affective (arousal) components. While the VRST has been shown to have good construct validity, the factor structure has yet to be explored. This study aimed to examine the factor structure of the VRST and compare the results with a lower dimensional (2D) computer-automated Stroop task (i.e., the Automated Neuropsychological Assessment Metrics - ANAM). METHOD: Data was drawn from college-aged students who completed the VRST and ANAM Stroop tasks (N = 115). Factor analyses utilized principal axis factoring (PAF), and output variables included percent of correct responses and response times the VRST and ANAM Stroop tasks. RESULTS: Results indicated that both Stroop tasks had two-factor solutions. Factor one measured response times and factor two measured accuracy. While factors respective of speed and accuracy factors were correlated across assessment modalities, within assessment factor correlations were low. CONCLUSIONS: The factors possibly indicated participants response styles in that they either focus on responding accurately or responding quickly to stimuli. Therefore, including throughput in future research examining either the ANAM Stroop task or VRST may provide useful insight into participant performance. Finally, because similar factor structures were observed for both the VRST and ANAM Stroop task this study provided additional support for the construct validity of a higher dimensional Stroop task, the VRST.

Effects of Transcranial Direct Current Stimulation on Cognitive and Affective Outcomes Using Virtual Stimuli: A Systematic Review.

Transcranial direct current stimulation (tDCS) is a noninvasive form of brain stimulation used to influence neural activity. While early tDCS studies primarily used static stimuli, there is growing interest in dynamic stimulus presentations using virtual environments (VEs). This review attempts to convey the state of the field. This is not a quantitative meta-analysis as there are not yet enough studies following consistent protocols and/or reporting adequate data. In addition to reviewing the state of the literature, this review includes an exploratory analysis of the available data. Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, studies were culled from several databases. Results from this review reveal differences between online and offline stimulation. While offline stimulation did not influence affective and cognitive outcomes, online stimulation led to small changes in affect and cognition. Future studies should include randomized controlled trials with larger samples. Furthermore, greater care needs to be applied to full data reporting (e.g., means, standard deviations, and data for their nonsignificant findings) to improve our understanding of the combined effects of virtual stimuli with tDCS.

The Cycle of Daily Stress and Sleep: Sleep Measurement Matters.

BACKGROUND: Disturbed sleep can be a cause and a consequence of elevated stress. Yet intensive longitudinal studies have revealed that sleep assessed via diaries and actigraphy is inconsistently associated with daily stress. PURPOSE: We expanded this research by examining daily associations between sleep and stress using a threefold approach to assess sleep: sleep diaries, actigraphy, and ambulatory single-channel electroencephalography (EEG). METHODS: Participants were 80 adults (mean age = 32.65 years, 63% female) who completed 7 days of stressor and sleep assessments. Multilevel models were used to examine bidirectional associations between occurrence and severity of daily stress with diary-, actigraphy-, and EEG-determined sleep parameters (e.g., total sleep time [TST], sleep efficiency, and sleep onset latency, and wake after sleep onset [WASO]). RESULTS: Participants reported at least one stressor 37% of days. Days with a stressor were associated with a 14.4-min reduction in actigraphy-determined TST (ß = -0.24, p = 0.030), but not with other actigraphy, diary, or EEG sleep measures. Nights with greater sleep diary-determined WASO were associated with greater next-day stressor severity (ß = 0.01, p = 0.026); no other diary, actigraphy, or EEG sleep measures were associated with next-day stressor occurrence or severity. CONCLUSIONS: Daily stress and sleep disturbances occurred in a bidirectional fashion, though specific results varied by sleep measurement technique and sleep parameter. Together, our results highlight that the type of sleep measurement matters for examining associations with daily stress. We urge future researchers to treat sleep diaries, actigraphy, and EEG as complementary-not redundant-sleep measurement approaches.

A Comparison of Virtual Reality Classroom Continuous Performance Tests to Traditional Continuous Performance Tests in Delineating ADHD: a Meta-Analysis.

Computerized continuous performance tests (CPTs) are commonly used to characterize attention in attention deficit-hyperactivity disorder (ADHD). Virtual classroom CPTs, designed to enhance ecological validity, are increasingly being utilized. Lacking is a quantitative meta-analysis of clinical comparisons of attention performance in children with ADHD using virtual classroom CPTs. The objective of the present systematic PRISMA review was to address this empirical void and compare three-dimensional (3D) virtual classroom CPTs to traditional two-dimensional (2D) CPTs. The peer-reviewed literature on comparisons of virtual classroom performance between children with ADHD and typically developing children was explored in six databases (e.g., Medline). Published studies using a virtual classroom to compare attentional performance between children with ADHD and typically developing children were included. Given the high heterogeneity with modality comparisons (i.e., computerized CPTs vs. virtual classroom CPTs for ADHD), both main comparisons included only population comparisons (i.e., control vs. ADHD) using each CPT modality. Meta-analytic findings were generally consistent with previous meta-analyses of computerized CPTs regarding the commonly used omission, commission, and hit reaction time variables. Results suggest that the virtual classroom CPTs reliably differentiate attention performance in persons with ADHD. Ecological validity implications are discussed pertaining to subtle meta-analytic outcome differences compared to computerized 2D CPTs. Further, due to an inability to conduct moderator analyses, it remains unclear if modality differences are due to other factors. Suggestions for future research using the virtual classroom CPTs are provided.