Assessment of Mental Workloads using Differential Dermal Potentials Recorded from in and around Ear

Differential dermal potentials is a non-invasive bio-potential signal acquired from the skin surface is a relatively new mode for human activity and behavior monitoring. Literature suggests acquiring differential dermal potentials from either hand or leg, which might be uncomfortable for long term usage. In the present work, for the first time we have acquired the differential dermal potentials from in and around the ear and have used that for monitoring mental workload. Experimental data were acquired from ear lobes and ear canals using two different devices while the participants were engaged in a mental arithmetic task. Thereafter, the signals are analyzed and a set of the most discriminating features are identified. Using these features, a cognitive load prediction model is developed. Results show that, for rest vs. load classification, we achieved an accuracy of 89% for ear canal data and 94.2% for ear lobe data. We also observed a positive co-occurrence of signals collected from these two locations. Thus, our proposed approach can be used for monitoring mental workload condition in real-life applications and is suitable for long term usage.