Wearables at work: mental relief or added stress?

When we walk, hear, and see all at once, our brain races to process the flood of sensory input. Like a bustling traffic hub at rush hour, it effortlessly manages countless streams of information to keep everything running smoothly. But what happens when the “traffic density” increases? The brain must continue to manage multiple tasks reliably - otherwise, conflicts may arise that impair performance.

Dr. Julian Elias Reiser, researcher in the IfADo groups “Experimental Ergonomics” and “Stress & Work Design”, conducted a study examining how people process acoustic and visual information while moving - and whether the senses compete with each other. A question that is gaining importance in an ever more complex working world.

IfADo: What new challenges does our brain face in today’s workplace?

Dr. Julian Elias Reiser: New technologies are increasing the amount of information we process every day at work. In fields such as logistics and assembly, smart glasses and in-ear headphones now deliver information – like inventory data or instructions – directly, replacing traditional paper lists. This saves time and increases productivity, but it also puts additional strain on the brain. We have to respond to acoustic or visual signals while moving at the same time. In our study, we set out to examine whether visual and auditory signals affect attention differently while walking — and whether they cause measurable declines in performance.

IfADo: What was your approach?

Dr. Julian Elias Reiser: Our participants solved cognitive tasks while alternating between standing and walking on a treadmill, either with or without impairment (Research Lab GRAIL). They switched tasks periodically, triggered by a visual or acoustic signal. While performing the task, we measured the participants’ brain activity using an EEG. The results showed that performing tasks while walking was often more challenging. Moreover, the type of cue used to signal task changes played a decisive role.

IfADo: How do you explain this?

Dr. Julian Elias Reiser: When cues were presented as sounds, many participants responded more quickly to simple tasks. However, for more difficult tasks or while walking, performance was better when the information was presented visually. In fact, visual cues even improved performance in some cases. This may be because the brain first needs to “translate” auditory information into a visual form before responding effectively. We know that the brain controls attention differently depending on the sense involved which even seems to be amplified while walking. Conflicts between thinking and movement arose not only due to the physical effort of walking, but also because information processing seemed to have changed fundamentally.

IfADo: What does this mean for work environments?

Dr. Julian Elias Reiser: Visual cues appear easier to process during complex tasks while moving, which is especially relevant for activities that involve complex movements. For the workplace, this means that information should be presented in a way that suits the specific work context. For tasks involving complex movements, screen instructions on a data headset can be helpful. Light signals at storage locations or floor-projected cues may also be effective. Auditory warnings or instructions are effective when people are mostly stationary or performing simple reactions. However, during complex or fast-paced tasks, they can lead to delays.