Multimodal Virtual Reality-Based Assessment of Adult ADHD: A Feasibility Study in Healthy Subjects

Neuropsychological assessments are often surprisingly inaccurate in mapping clinically-reported attention-deficit hyperactivity disorder (ADHD) symptoms, presumably due to their low ecological validity. Virtual reality (VR) might offer a potential solution for this problem, given its capability to generate standardized and yet highly realistic virtual environments. As the first adaptation of existing virtual classroom scenarios to an adult population, we developed a Virtual Seminar Room (VSR) for multimodal characterization of ADHD symptoms. To test its feasibility, N = 35 healthy participants were immersed into the VSR via a head-mounted display and carried out a VR-embedded continuous performance task (CPT) under varying levels of distractions in two experimental blocks (24 min each). CPT performance, electroencephalography (EEG) measures, and head movements (actigraphy) were simultaneously recorded and analyzed offline. Although CPT performance remained constant throughout the task, head movements increased significantly from Block 1 to Block 2. In addition, EEG theta (4–7 Hz) and beta (13–30 Hz) power was higher during Block 1 than Block 2, and during distractor-present than distractor-absent phases. Moreover, P300 amplitudes were higher during Block 1 than Block 2, and P300 latencies were prolonged in distractor-absent compared with distractor-present phases. Although the paradigm awaits further improvements, this study confirms the general feasibility of the VSR and provides a first step toward a multimodal, ecologically valid, and reliable VR-based adult ADHD assessment.

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Regarding ADHD assessment during childhood and adolescence, two similar, but independently-developed virtual test environments have been investigated over the last years: the Virtual Classroom by Rizzo et al. (2006) and the AULA Nesplora by Iriarte et al. (2016). In the Virtual Classroom, children with ADHD are immersed into a virtual environment that resembles an ordinary classroom. Sitting at a desk surrounded by virtual classmates, the children are instructed to follow a classical visual CPT that is presented on the blackboard. To enhance reality closeness and incorporate a measure of distractibility and external interference control, different visual, auditory, and audio-visual distractors inside the virtual environment (e.g., a paper-plane flying through the room) can be presented during the task (Parsons & Rizzo, 2019). The design of the AULA Nesplora is similar, except that it contains both visual and auditory CPT stimuli (Iriarte et al., 2016). Both virtual test environments have been shown to differentiate between ADHD children/adolescents and healthy controls, with ADHD patients committing more overall errors in the CPT (Areces et al., 2018; Mühlberger et al., 2016; Neguț et al., 2017; Parsons et al., 2007; Rizzo et al., 2006) and displaying a larger amount of head- and overall body-movements during task completion (Areces et al., 2018; Parsons et al., 2007; Rizzo et al., 2006). In the Virtual Classroom, ADHD patients were additionally more affected by the insertion of distractors than healthy controls (Neguț et al., 2017; Parsons et al., 2007; Rizzo et al., 2006). Moreover, Adams et al. (2009) found a higher classification rate for discriminating ADHD patients from healthy controls if the classifier was trained on a VR-based CPT compared with a traditional CPT.