The countermeasure of driver fatigue is valuable for reducing the risk of accidents caused by vigilance failure during prolonged driving. Listening to the radio (RADIO) has been proven to be a relatively effective “in-car” countermeasure. However, the connectivity analysis, which can be used to investigate its alerting effect, is subject to the issue of signal mixing. In this study, we propose a novel framework based on clustering and entropy to improve the performance of the connectivity analysis to reveal the effect of RADIO to maintain driver alertness. Regardless of reducing signal mixing, we introduce clustering algorithm to classify the functional connections with their nodes into different categories to mine the effective information of the alerting effect. Differential entropy (DE) is employed to measure the information content in different brain regions after clustering. Compared with the Louvain-based community detection method, the proposed method shows more superior ability to present RADIO effectin confused functional connection matrices. Our experimental results reveal that the active connection clusters distinguished by the proposed method gradually move from frontal region to parieto-occipital regionwith the progress of fatigue, consistent with the alpha energy changes in these two brain areas. The active class of the clusters in parieto-occipital region significantly decreases and the most active clusters remain in the frontal region when RADIO is taken. The estimation results of DE confirm the significant change (p < 0.05) of information content due to the cluster movements. Hence, preventing the movement of the active clusters from frontal region to parieto-occipital region may correlate with maintaining driver alertness. The revelation of alerting effect is helpful for the targeted upgrade of fatigue countermeasures.

Using the Road Situation Video Test Paradigm and Eye-Tracking Analysis Method, according to the two-stage processing model of hazard perception (HP), this study divides HP into two stages: perception and behaviour response, and compares the different roles of sensation seeking level in two different processing stages of perception and behaviour response when adolescents are crossing the road. The results show that: (1) In the perception stage, adolescents with high sensation seeking, especially boys with high sensation seeking perceive danger faster than boys with low sensation seeking and girls, they are more aware of danger. Particularly, boys with high sensation seeking show a stronger advantage of attention processing to hazard in the early stage of perception processing from 8^th and 9^th grades. (2) In the behaviour response stage, adolescents with high sensation seeking, especially the boys are less sensitive, have stricter judgment criteria, and are more likely to make dangerous decisions when crossing the road. Girls with different sensation seeking levels are more sensitive and more cautious when crossing the road, make the probability of judging dangerous situation is higher, so they choose a more conservative way, and may be less likely to across the road.