Study Claims Electronic Face Tattoos Can Help Manage Stress At Work

A revolutionary/goofy-looking wireless forehead e-tattoo has been developed that can accurately estimate mental workloads in real-time, offering a significant leap forward for human-in-the-loop systems in high-stakes environments. This groundbreaking device, detailed in an article in the August 15 issue of Device by authors Heeyong Huh, Hyonyoung Shin, Hongbian Li, and colleagues from The University of Texas at Austin and the U.S. Army Aeromedical Research Laboratory, promises to transform how we monitor cognitive states in fields like aviation, healthcare, and robotics.

Up till now, methods for monitoring mental workload, such as electroencephalography (EEG) and electrooculography (EOG) devices, have been hampered by their obtrusive nature, cumbersome wiring, and susceptibility to motion artifacts. Such limitations have made real-world applications challenging, if not impossible, for individuals actively engaged in tasks.

However, a newly unveiled forehead electronic tattoo addresses these critical issues with an innovative setup. Unlike conventional systems, this ultra-thin, conformable sensor utilizes composite-coated graphite-deposited polyurethane (APC-GPU) electrodes mated to a conductive adhesive film. These specially designed electrodes offer superior adhesion to the skin and significantly reduce motion artifacts, ensuring stable, high-fidelity signal acquisition even during dynamic movements. The e-tattoo's ultra-thin, reusable design also ensures exceptional comfort and compatibility with existing headgear, such as helmets used by pilots or hard hats worn by industrial operators.

The research team successfully demonstrated the e-tattoo's capabilities on six participants in an N-back test. N-backs are cognitive tasks used to assess working memory and attention where participants are presented with a sequence of stimuli (like letters or numbers) and must indicate when the current stimulus matches the one presented in steps earlier in the sequence. Using the collected EEG and EOG signals, the researchers found a strong correlation between the physiological signals captured by the e-tattoo and the participants' mental workload levels.

Furthermore, the team developed a sophisticated machine-learning model that, trained on these physiological features, successfully estimates variations in mental workload across different task difficulties.

The implications of this technology are promising. Real-time monitoring of operator cognitive condition can dramatically enhance safety and performance in human-in-the-loop systems. Imagine a pilot whose cognitive load is continuously monitored, allowing for proactive adjustments to prevent errors. Or a surgeon whose mental fatigue can be detected before it impacts critical decisions. 

However, one of the authors of the study Lu Nanshu indicated that stress management doesn't mean temporarily switching to an easier task. Lu said, "Previous studies indicated that the optimal mental performance occurs when the mental workload demand is not too low or too high. When it’s too low, it’s very boring, and the people will just lose focus.”