Ways to Improve Multitasking: Effects of Predictability after Single- and Dual-Task Training

Design guidelines for limiting and eliminating virtual reality-induced symptoms and effects at work: a comprehensive, factor-oriented review

Virtual reality (VR) can induce side effects known as virtual reality-induced symptoms and effects (VRISE). To address this concern, we identify a literature-based listing of these factors thought to influence VRISE with a focus on office work use. Using those, we recommend guidelines for VRISE amelioration intended for virtual environment creators and users. We identify five VRISE risks, focusing on short-term symptoms with their short-term effects. Three overall factor categories are considered: individual, hardware, and software. Over 90 factors may influence VRISE frequency and severity. We identify guidelines for each factor to help reduce VR side effects. To better reflect our confidence in those guidelines, we graded each with a level of evidence rating. Common factors occasionally influence different forms of VRISE. This can lead to confusion in the literature. General guidelines for using VR at work involve worker adaptation, such as limiting immersion times to between 20 and 30 min. These regimens involve taking regular breaks. Extra care is required for workers with special needs, neurodiversity, and gerontechnological concerns. In addition to following our guidelines, stakeholders should be aware that current head-mounted displays and virtual environments can continue to induce VRISE. While no single existing method fully alleviates VRISE, workers' health and safety must be monitored and safeguarded when VR is used at work.

Contributions of open-loop and closed-loop control in a continuous tracking task differ depending on attentional demands during practice

Improving tracking performance requires numerous adjustments in the motor system, including peripheral muscle functions and central motor commands. These commands can rely on sensory feedback processing during tracking, i.e., closed-loop control. In the case of repeated tracking sequences, these commands can rely on an inner representation of the target trajectory to optimize pre-planning, i.e., open-loop control. Implicit learning in a continuous tracking task with repeated sequences proves the availability of an inner target representation, which emerges by learning task regularities, even without explicit knowledge. We hypothesize that the actual use of open-loop or closed-loop control is influenced by the demand for attention. Specifically, we suggest that closed-loop control and its development during practice need attentional resources, whereas open-loop control can work and evolve in a more automatic way without attentional demands. To test this, we investigated motor-control strategies when extensively practicing a continuous compensatory force-tracking task using isometric leg muscle activation, either as a single-motor task or as a motor-cognitive dual task. After training, we found evidence for predominantly closed-loop control in the single-task training group and for open-loop control in the dual-task training group. In particular, we ascertained dual-task motor costs and a weakly developed implicit knowledge of task regularities in the single-task training group. In contrast, in the dual-task training group dual-task motor costs disappeared, while implicit learning was clearly observed. We conclude that motor-cognitive dual-task training may boost implicit motor learning, without necessarily impeding concurrent improvement in the cognitive task. Data repository: reserved doi: https://doi.org/10.5281/zenodo.6759377.