Gaze-based attention refocusing training in virtual reality for adult attention-deficit/hyperactivity disorder

A comparative diagnostic study using clinical and multimodal assessment, including functional neuroimaging and oculomotricity tools, to differentiate ADHD in young patients from healthy control group

AIM

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder that may persist into adulthood, with no established objective diagnostic tool yet. This study aims to propose a multimodal objective assessment tool involving clinical assessments, functional neuroimaging, and oculomotricity measurement for ADHD in young adults.

METHODS

Seventy-one medication-naïve patients and 71 healthy controls (HCs) aged 18 to 28 underwent clinical interviews, Conners' Adult ADHD Rating Scale (CAARS) questionnaire, functional near-infrared spectroscopy (fNIRS), oculomotricity task, and Conners' Continuous Performance Task (CPT) 3rd edition. Student's t-tests with Bonferroni's correction were performed to compare the performance between groups, and logistic regression was used for classification.

RESULTS

ADHD patients had significantly lower frontal hemodynamic response during verbal fluency task (VFT) (P = 0.0003), more anticipatory eye movements during overlap task (P = 0.0006), higher latency (P < 0.0001), anticipatory (P < 0.0001), and errors (P < 0.0001) during anti-saccade task, as well as higher commission errors (P < 0.0001) and standard deviation in hit reaction time (HRT) (P = 0.0018). The multivariate logistic regression model featuring these seven parameters from the three objective tests (fNIRS-VFT, oculomotricity, and CPT) yielded an area under the receiver operating characteristic curve (AUC) value of 0.892 (95% confidence interval (CI): 0.840-0.944), with sensitivity and specificity of 80.28% and 84.51%, respectively.

CONCLUSION

This multimodal assessment offered an accurate diagnostic tool for ADHD in young adults and laid the foundation for future machine-learning approaches.

Selective attention and sensitivity to auditory disturbances in a virtually-real Classroom: Comparison of adults with and without AD(H)D

Many people, and particularly individuals with Attention Deficit (Hyperactivity) Disorder (AD(H)D), find it difficult to maintain attention during classroom learning. However, traditional paradigms used to evaluate attention do not capture the complexity and dynamic nature of real-life classrooms. Using a novel Virtual Reality platform, coupled with measurement of neural activity, eye-gaze and skin conductance, here we studied the neurophysiological manifestations of attention and distractibility, under realistic learning conditions. Individuals with AD(H)D exhibited higher neural responses to irrelevant sounds and reduced speech tracking of the teacher, relative to controls. Additional neurophysiological measures, such the power of alpha-oscillations and frequency of gaze-shifts away from the teacher, contributed to explaining variance in self-reported AD(H)D symptoms across the sample. These ecologically-valid findings provide critical insight into the neurophysiological mechanisms underlying individual differences in the capacity for sustained attention and the proneness to distraction and mind-wandering, experienced in real-life situations.

Virtual reality-assisted prediction of adult ADHD based on eye tracking, EEG, actigraphy and behavioral indices: a machine learning analysis of independent training and test samples

Given the heterogeneous nature of attention-deficit/hyperactivity disorder (ADHD) and the absence of established biomarkers, accurate diagnosis and effective treatment remain a challenge in clinical practice. This study investigates the predictive utility of multimodal data, including eye tracking, EEG, actigraphy, and behavioral indices, in differentiating adults with ADHD from healthy individuals. Using a support vector machine model, we analyzed independent training (n = 50) and test (n = 36) samples from two clinically controlled studies. In both studies, participants performed an attention task (continuous performance task) in a virtual reality seminar room while encountering virtual distractions. Task performance, head movements, gaze behavior, EEG, and current self-reported inattention, hyperactivity, and impulsivity were simultaneously recorded and used for model training. Our final model based on the optimal number of features (maximal relevance minimal redundancy criterion) achieved a promising classification accuracy of 81% in the independent test set. Notably, the extracted EEG-based features had no significant contribution to this prediction and therefore were not included in the final model. Our results suggest the potential of applying ecologically valid virtual reality environments and integrating different data modalities for enhancing robustness of ADHD diagnosis.

Bipolar-ADHD comorbidity: screening for differences in neurocognition and virtual reality-based cognitive performance

OBJECTIVES

Identification of comorbid attention-deficit/hyperactivity disorder (ADHD) in patients with bipolar disorder (BD) is complicated by overlapping cognitive symptoms and methodological challenges. This cross-sectional study investigated whether virtual reality (VR)-based cognitive assessment that mimics daily life cognitive challenges can aid in the detection of sustained attention impairment in BD individuals with comorbid ADHD (BD + ADHD).

METHODS

Forty-nine fully or partially remitted outpatients with BD, of whom 14 (24%) had BD + ADHD, were assessed with the Cognition Assessment in Virtual Reality (CAVIR) test, including a sustained attention test that involves distractions, and the Screen for Cognitive Impairment in Psychiatry (SCIP). Patients were also rated for mood symptoms and functioning and completed questionnaires assessing subjective cognition and quality of life. Patients' cognitive impairment on the SCIP was estimated with reference to n = 100 demographically comparable healthy control participants.

RESULTS

BD + ADHD participants exhibited more pronounced performance deficits on the CAVIR sustained attention test (t(48) = 2.15, p = .037, d = .66). Notably, deficits on this test were proportional to self-reported daily life concentration difficulties in BD + ADHD individuals. Exploratory analyses revealed that BD + ADHD participants also displayed greater impairment on the SCIP working memory- and delayed verbal learning subtests and greater subjective cognitive complaints than BD patients without this comorbidity (p-levels < .001), but only the difference in subjective cognition survived correction for multiple comparisons (F(1,47) = 14.13, p = .005, np2 = 0.24).

CONCLUSION

Screening for deficits in sustained attention with an ecologically valid VR test involving distracting stimuli may be useful for identifying BD + ADHD individuals.

Influence of open-source virtual-reality based gaze training on navigation performance in Retinitis pigmentosa patients in a crossover randomized controlled trial

METHODS

A group of RP patients (n = 8, aged 20-60) participated in a study consisting of two 4-week-phases, both carried out by the same patient group in randomized order: In the 'training phase', participants carried out a Virtual-Reality gaze training for 30 minutes per day; In the 'control phase', no training occurred. Before and after each phase, participants were tasked to move through a randomized real-world obstacle course. Navigation performance in the obstacle course as well as eye-tracking data during the trials were evaluated. The study is registered at the German Clinical Trials Register (DRKS) with the ID DRKS00032628.

RESULTS

On average, the time required to move through the obstacle course decreased by 17.0% after the training phase, the number of collisions decreased by 50.0%. Both effects are significantly higher than those found in the control phase (p < 0.001 for required time, p = 0.0165 for number of collisions), with the required time decreasing by 5.9% and number of collisions decreasing by 10.4% after the control phase. The average visual area observed by participants increases by 4.41% after training, however the effect is not found to be significantly higher than in the control phase (p = 0.394).

CONCLUSION

The performance increase over the training phase significantly surpasses the natural learning effect found in the control phase, suggesting that Virtual-Reality based gaze training can have a positive effect on real-world navigation tasks for patients with RP. The training is available as work-in-progress open-source software.

Alpha modulation via transcranial alternating current stimulation in adults with attention-deficit hyperactivity disorder

Background

One potential therapy treating attention-deficit/hyperactivity disorder (ADHD) is to modulate dysfunctional brain activations using brain stimulation techniques. While the number of studies investigating the effect of transcranial direct current stimulation on ADHD symptoms continues to increase, transcranial alternating current stimulation (tACS) is poorly examined. Previous studies reported impaired alpha brain oscillation (8-12 Hz) that may be associated with increased attention deficits in ADHD. Our aim was to enhance alpha power in adult ADHD patients via tACS, using different methods to explore potential therapeutic effects.

Methods

Undergoing a crossover design, adults with ADHD received active and sham stimulation on distinct days. Before and after each intervention, mean alpha power, attention performance, subjective symptom ratings, as well as head and gaze movement were examined.

Results

Frequency analyses revealed a significant power increase in the alpha band after both interventions. Despite a trend toward an interaction effect, this alpha power increase was, however, not significantly higher after active stimulation compared to sham stimulation. For the other measures, some additional pre-post effects were found, which were not intervention-related.

Conclusion

Our study cannot provide clear evidence for a tACS-induced increase in alpha power in adult ADHD patients, and thus no stimulation related improvement of attention parameters. We provide further recommendations for the future investigation of tACS as a potential ADHD treatment.