Neuropsychological assessment of visual selective attention and processing capacity with head-mounted displays.

OBJECTIVE: Neuropsychological patients often suffer from impairments in visual selective attention and processing capacity components. Their assessment demands a high standardization of testing conditions, which is difficult to achieve across institutions. Head-mounted displays (HMDs) provide a solution. These virtual reality devices cover the entire visual field in a shielded way and thus keep visual stimulation constant. For neuropsychological assessment with HMDs, sufficient reliability is required. We have previously demonstrated that an early developer version of an HMD can be used to reliably measure components of visual processing capacity. However, it is unclear whether this also holds for the assessment of components of visual selective attention. Moreover, it has yet to be established whether now commercially available HMDs are capable of reliable neuropsychological assessment. METHOD: We assessed the test-retest reliabilities of several components of visual selective attention and processing capacity of healthy subjects with the commercially available HTC Vive. Using an assessment procedure (combiTVA) derived from the theory of visual attention (TVA; Bundesen, 1990), we measured attentional selectivity, lateral bias, processing speed, visual working memory capacity, and the threshold of conscious perception. We compared the reliabilities of these components measured with the HTC Vive with those of a cathode ray tube (CRT) screen, the gold standard of visual presentation in the laboratory. RESULTS: Both devices provided comparable reliabilities. CONCLUSIONS: Thus, HMDs fulfill the requirement to replace standard screens. With their inherent visual standardization and portability, they offer unprecedented opportunities for neuropsychological assessment, such as computerized bedside testing and comparisons of test values across institutions. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Ultrahigh temporal resolution of visual presentation using gaming monitors and G-Sync.

Vision unfolds as an intricate pattern of information processing over time. Studying vision and visual cognition therefore requires precise manipulations of the timing of visual stimulus presentation. Although standard computer display technologies offer great accuracy and precision of visual presentation, their temporal resolution is limited. This limitation stems from the fact that the presentation of rendered stimuli has to wait until the next refresh of the computer screen. We present a novel method for presenting visual stimuli with ultrahigh temporal resolution (<1 ms) on newly available gaming monitors. The method capitalizes on the G-Sync technology, which allows for presenting stimuli as soon as they have been rendered by the computer's graphics card, without having to wait for the next screen refresh. We provide software implementations in the three programming languages C++, Python (using PsychoPy2), and Matlab (using Psychtoolbox3). For all implementations, we confirmed the ultrahigh temporal resolution of visual presentation with external measurements by using a photodiode. Moreover, a psychophysical experiment revealed that the ultrahigh temporal resolution impacts on human visual performance. Specifically, observers' object recognition performance improved over fine-grained increases of object presentation duration in a theoretically predicted way. Taken together, the present study shows that the G-Sync-based presentation method enables researchers to investigate visual processes whose data patterns were concealed by the low temporal resolution of previous technologies. Therefore, this new presentation method may be a valuable tool for experimental psychologists and neuroscientists studying vision and its temporal characteristics.

Using the virtual reality device Oculus Rift for neuropsychological assessment of visual processing capabilities.

Neuropsychological assessment of human visual processing capabilities strongly depends on visual testing conditions including room lighting, stimuli, and viewing-distance. This limits standardization, threatens reliability, and prevents the assessment of core visual functions such as visual processing speed. Increasingly available virtual reality devices allow to address these problems. One such device is the portable, light-weight, and easy-to-use Oculus Rift. It is head-mounted and covers the entire visual field, thereby shielding and standardizing the visual stimulation. A fundamental prerequisite to use Oculus Rift for neuropsychological assessment is sufficient test-retest reliability. Here, we compare the test-retest reliabilities of Bundesen's visual processing components (visual processing speed, threshold of conscious perception, capacity of visual working memory) as measured with Oculus Rift and a standard CRT computer screen. Our results show that Oculus Rift allows to measure the processing components as reliably as the standard CRT. This means that Oculus Rift is applicable for standardized and reliable assessment and diagnosis of elementary cognitive functions in laboratory and clinical settings. Oculus Rift thus provides the opportunity to compare visual processing components between individuals and institutions and to establish statistical norm distributions.