Gaze behavior and human error in distracted driving: Unlocking the complexity of articulatory rehearsal mechanism

This study reports development of an experimental paradigm named as 'Direction Following in Distracted Driving - Suppression of Articulatory Rehearsal Mechanism (D3-SARM)'. It investigates the effect of suppressed articulatory rehearsal mechanism (ARM) on gaze behavior and driving performance in a naturalistic driving environment. Drivers (N = 45) voluntarily participated in the study and drove an instrumented vehicle on a two-lane track. They were required to follow certain directions displayed on the direction signboards that were installed along the track. There were three levels of suppression of ARM namely, non-suppression (NS), simple suppression (SS), and complex suppression (CS). Equal number of participants were randomly assigned to each level of suppression. The results demonstrate that there are significantly lesser fixation durations and fixation counts under CS of ARM as compared to the other two levels. Overall driving error analysis revealed that there are more significant errors under CS as compared to SS and NS. Moreover, drivers committed more slips than lapses irrespective of the levels of suppression. On the whole, this study suggests that suppression of ARM affects gaze behavior and compromises driving performance. Also, even in the case of drivers being unable to have fixation on target visual information irrespective of non-suppressed ARM or suppressed ARM, drivers paid visits.