A novel optical non-intrusive method for measuring acoustic startle reflex in humans

Abstract

Objective: The development of a new non-intrusive optical system for remotely measuring acoustic startle reflex (ASR) in humans. Approach: The eye reflex movement during an acoustic stimulation session is recorded through a high-speed digital camera. The eyes region is isolated by the rest of the face by an advanced pyramid-like feature detection algorithm, which greatly reduces the number of false positives. A separate Lucas–Kanade optical flow routine is designed for the eyeblink movement detection and the startle eyeblink reflex (SEBR) curve extraction. Image masking is implemented for the elimination of unwanted artifacts caused mainly by voluntary eye movement. The proposed system was tested along with a valid EMG system on a sample of 32 healthy randomly selected adults, and the results were compared in order to measure the system’s degree of reliability. Main results: To assess the proposed method’s validity the EMG data was used as a benchmark. The results showed strong correlation between EMG and Camera acquired results, which proves the validity of the proposed method. Furthermore, by comparing the response probability and the signal to noise ratio (SNR) for the two techniques, we proved that the proposed method can surpass the traditional EMG system in terms of accuracy and reliability. Significance: The proposed technique presents a simple, robust and reliable non-intrusive means of measuring ASR in humans, with the potential of future implementation on various ASR psychophysiology experiments, such as the study of PPI.

A narrative review of the interconnection between pilot acute stress, startle, and surprise effects in the aviation context: Contribution of physiological measurements

“…Other measures such as facial expressions are quite effective as it has been suggested that fear is a measurable aspect of startle (Dismukes et al, 2015 ). The optical system technique developed to remotely measure acoustic startle reflex (ASR) in humans also seems to be a promising technique (Balogiannis et al, 2020 ). Regarding surprise, evidence has been shown regarding the use of heart and respiratory rate, GSR, and pupil dilation.…”

Research Progress in the Study of Startle Reflex to Disease States

“…Other novel measurement methods include the new optical non-invasive method, 9 mobile acoustic startle reflex monitoring system (MARS), 10 and video freeze monitoring system. 5 The Balogiannis team 9 believe that the new optical non-invasive method is simple and reliable, making it superior to traditional EMG systems in terms of effectiveness, accuracy, and reliability. MARS 10 is the first mobile phone-based monitoring system.…”