EMG and GSR signals for evaluating user's perception of different types of ceramic flooring

Most product evaluations rely on questionnaires to convert subjective data, or user opinion, to objective data. However, some users may feel inhibited or unable to decide in cases where product differences are very subtle. Other techniques such as physiological measurements can contribute to the understanding of perceptions by incorporating measurements that do not involve conscious processes. This paper presents the results of a research project concerning the use of three biosignals for evaluating user perception: electromyography (EMG) activity of the zygomaticus major, EMG of the corrugator supercilii, and galvanic skin response (GSR). These signals were recorded in the subjects while three calibration images (neutral face, smiling face and frowning face) and eight ceramic flooring images were being projected. The results revealed that types of ceramic tile flooring can be differentiated by GSR values, creating two groups elicited by the users’ emotional response. On the other hand, significant differences were found in the EMG signals, especially in the zygomaticus major, elicited by the calibration images. The results indicate that the analysis of this type of signal has a potential use in the understanding of product perception. The results provided by the recording of zygomaticus major signals while subjects observed the calibration images show that the smiling face image elicited positive activity of the zygomaticus major.Relevance to industryIdentification of the aspects of product design that are considered to be the most important to potential users is an essential field for many industries. Numerous methodological techniques have been developed to try to understand these processes, nearly all of which are based on user opinion. However, it seems clear from a scientific point of view that subconscious processes play an important role in the aspects relating to perception and decision-making. This paper proposes a feasible approach using non-invasive physiological measurements.