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内容記述 |
Honda has set a goal to achieve zero fatalities in tra"c accidents by 2050. To realize this goal, it is necessary to elucidate and eradicate the causes of human errors by drivers. Previous studies have suggested that eye movements during driving reflect human error and are related to driving safety. However, little is known about the cognitive and neural processes underlying drivers’ visual behavior. To investigate this, we recorded fMRI and eye-tracking data while healthy adults (22-78 years old) operated a driving simulator. The driving simulator was constructed inside an MRI scanner and composed of a steering wheel with winker buttons, an accelerator pedal, and a brake pedal. Participants drove in target or other trials. In target trials, a road with risks, such as a car in the adjacent lane passing the participants’ driving car, was presented, and participants were required to change lanes to the right safely. At the end of a trial, a tra"c light in front of an intersection turned red, and participants had to put on a brake pedal to stop. One trial took about thirty seconds. In the other trials, participants drove on the road with a lane change to the left or without lane change or drove straightly on a road without any other tra"c participants. We focused on the data of target trials and analyzed the relationship between the visual behavior to a risky car and the maximum deceleration, which becomes greater when drivers suddenly put on the brake pedal at the tra"c light. The behavioral data showed that the number of fixations was negatively correlated, and the duration from the last fixation to the time when the risk was eliminated was positively correlated to the maximum deceleration. Next, we investigated what neural processes underlie these visual behaviors. The fMRI data showed that the duration from the last fixation to the time when the risk was eliminated modulated activations in the angular gyrus and supramarginal gyrus at the last fixation. In previous studies, it is known that the angular gyrus is related to theory of mind, and the supramarginal gyrus is related to integration of semantic and technical information. These results suggest that drivers who operate the brake pedal gently keep paying attention to other tra"c participants until risks are eliminated to guess the mental state of other drivers, and then decide their own behavior. Based on this insight, it is possible that encouraging drivers to estimate the mental state of others can lead to more gentle driving operations. |
