Contemporary work environments require humans to process audiovisual
information displays whilst moving around the world. The attentional
demands associated with using devices such as in-ear headphones and
head-mounted displays may be significantly influenced by varying
locomotor demands, yet this relationship remains poorly understood. This
study investigates the interplay of information presentation modality,
movement state, and cognitive task difficulty. In a virtual reality
laboratory, 22 participants performed a cued task-switch paradigm with
two difficulty levels while standing, walking, or walking with
perturbations on a treadmill. We used a questionnaire, behavioral and
mobile EEG data to investigate cognitive-motor interference. We find
that locomotion interfered with cognitive task performance, and that the
presentation modality of task-switch notification modified the nature of
this interference. While auditory cue presentation resulted in faster
responses under low cognitive load conditions, visual information
presentation was less impaired by higher cognitive and locomotor
demands. A detailed analysis of the EEG response to cues addressed these
differences in terms of multi-modal attentional mechanisms. Hence,
wearable information presentation should be tailored to the specific
needs, particularly for cognitively demanding information in mobile work
settings.