抄録
Due to the amplitude-frequency characteristic of the steady-state visual-evoked potential, the flickering frequency of a steady-state visual-evoked potential-based brain-computer interface is typically lower than 20Hz. However, a visual flicker with a flashing frequency below the critical flicker-fusion frequency often makes subjects feel edgy and causes visual discomfort. This study aims to quantitatively evaluate the relationship between user's visual discomfort and the nasal skin temperature (NST). NST is calculated using the thermal image of the human face. The correlations between the physiological index (NST) and the psychophysical index (based on responses on the visual analogue scale (VAS)) were both considered. The results of VAS are a psychometric response index, which can be used in questionnaires.
This study presents a novel technique based on the nasal skin temperature to measure user's visual discomfort. A change in temperature was studied in accordance with the usual method. The results were similar to the known symptoms, which are related to optical sensitivity. Moreover, the frequency characteristics of NST were studied. As a result, the relationship between user's visual discomfort and frequency characteristics of NST dynamics is very strong under 0.01Hz.
