認知プロセスに基づく全身反応時間と道路横断行動の関連性

抄録

　The purpose of this study was to clarify the relationship between reaction time (RT) and traffic accidents and examine whether RT measurement is useful as a method for evaluating the risk of traffic accident occurrence. The subjects were 79 healthy elderly women (mean age; 77.9 ± 5.4 years). We employed a walking environment simulator system (hereafter, walking simulator), which is considered to have the potential to evaluate the individual risk of traffic accident involvement. We assessed 2 RT parameters: simple reaction time and multitask reaction time. Both parameters were assessed as the average value of 3 measurements (hereafter, simple reaction time: SRT; multi-task reaction time: MRT). Based on the results obtained with the walking simulator, the subjects were classified as either an accident group (n = 22) or an accident avoidance group (n = 57). Using 2-way ANOVA, we compared the SRT and MRT as dependent variables and the group and task factors as independent variables. When a significant interaction was observed, a significance test between levels was performed for each factor using an unpaired t-test and a paired t-test. As a result, a significant main effect was observed in the task factors, and a significant interaction was observed. Paired t-tests were therefore performed for the group factors. Consequently, a significant difference was detected between the accident and the avoidance groups, and MRT was slower than SRT in both groups. In addition, there was no significant inter-group difference in SRT with unpaired t-test for RT for each task, but a significant inter-group difference was observed in MRT. Therefore, the accident group had a significantly longer RT than the accident avoidance group. These results suggest that the MRT could be a substitute parameter for assessing the risk of traffic accident occurrence using a walking simulator, making it an effective index for screening older individuals (i.e. exploratory evaluation of whether or not an accident is likely to occur). At the same time, promoting appropriate attention and improving traffic safety awareness among older people is critical for reducing traffic accidents involving older people crossing the road.