Sajad Najar - Academia.edu (original) (raw)
Papers by Sajad Najar
Lecture notes in networks and systems, 2022
Journal of Transportation Safety & Security, 2019
Driving is a complex task performed in a dynamic environment whereby visuospatial information is ... more Driving is a complex task performed in a dynamic environment whereby visuospatial information is a critical aspect of driver cognition. Drivers' interaction with the in-vehicle interfaces challenges their ability to respond to the dynamic traffic scenes efficiently. This study examines the effect of in-vehicle object and spatial distractions on drivers' gaze behavior and driving performance. An experimental paradigm named as direction following in distracted drivingobject and spatial (D3-OS) was developed for this study. An instrumented vehicle was voluntarily driven by 47 drivers on a two-lane test-track (data from seven participants were invalid, hence not included in the analysis). Four direction signboards were installed on the left side along the track and the drivers were required to drive according to the directions displayed on these signboards. Drivers were instructed to provide responses to the distracting stimuli shown on an in-vehicle display monitor that was attached to the dashboard. Novice and expert drivers (20 in each group) were randomly assigned to object and spatial distractions. The results demonstrate that compared to spatial distraction, during object distraction, fixation durations and fixation counts on area of interest (AOI) are significantly reduced and driving errors (i.e., both slips and lapses) are significantly increased. Novice drivers committed significantly more slips and lapses as compared to expert drivers. Furthermore, an increased cognitive workload (CWL) is associated with an increase in the occurrence of slips and lapses. On the whole, the results of the study signify the importance of strict enforcement of traffic regulations related to distracted driving more stringently in the case of novice drivers.
Perceptual and Motor Skills
In-vehicle interactive systems are widely used in modern vehicles. While these systems serve vari... more In-vehicle interactive systems are widely used in modern vehicles. While these systems serve various purposes, they are also potential distracters for drivers. In this study we investigated the effect of in-vehicle spatial distractions on driving errors and driver gaze behavior by developing an experimental paradigm named, “Direction Following in Distracted Driving – Spatial: Simultaneous and Sequential (D3-SSS).” Twenty-seven drivers voluntarily participated and were required to drive an instrumented vehicle on a two-lane test-track, following directions shown on direction signboards. While driving, drivers were required to respond to in-vehicle spatial distracting stimuli presented to them through a monitor attached to the dashboard. The drivers were randomly assigned to in-vehicle spatial-simultaneous and spatial-sequential distraction conditions. Our results demonstrated that, in comparison with spatial-sequential distractions, there were shorter eye fixation durations and fewer...
Drivers get driving related information mainly through visual, auditory, and haptic sensory chann... more Drivers get driving related information mainly through visual, auditory, and haptic sensory channels but it is predominantly based on the information received through visual senses. In working memory visual information fades away faster than the auditory information and in order to retain the visual information for a longer duration it gets recoded into phonological information through Articulatory Rehearsal Mechanism (ARM) [1]. After every 2 s, ARM recites and rehearses the phonological information making it to re-enter into the phonological store, where it starts to decay again immediately [1, 2]. Individuals when engaged in processing visual information in order to perform driving and if there is suppression of ARM chances are high that visual information processing will be compromised. This distraction is ought to suppress the visual information from being rehearsed and remembered acoustically. The present study investigates the effect of suppression of ARM on driving performanc...
Transportation Research Part F: Traffic Psychology and Behaviour, 2018
This study reports development of an experimental paradigm named as ‘Direction Following in Distr... more 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 signif...
Lecture notes in networks and systems, 2022
Journal of Transportation Safety & Security, 2019
Driving is a complex task performed in a dynamic environment whereby visuospatial information is ... more Driving is a complex task performed in a dynamic environment whereby visuospatial information is a critical aspect of driver cognition. Drivers' interaction with the in-vehicle interfaces challenges their ability to respond to the dynamic traffic scenes efficiently. This study examines the effect of in-vehicle object and spatial distractions on drivers' gaze behavior and driving performance. An experimental paradigm named as direction following in distracted drivingobject and spatial (D3-OS) was developed for this study. An instrumented vehicle was voluntarily driven by 47 drivers on a two-lane test-track (data from seven participants were invalid, hence not included in the analysis). Four direction signboards were installed on the left side along the track and the drivers were required to drive according to the directions displayed on these signboards. Drivers were instructed to provide responses to the distracting stimuli shown on an in-vehicle display monitor that was attached to the dashboard. Novice and expert drivers (20 in each group) were randomly assigned to object and spatial distractions. The results demonstrate that compared to spatial distraction, during object distraction, fixation durations and fixation counts on area of interest (AOI) are significantly reduced and driving errors (i.e., both slips and lapses) are significantly increased. Novice drivers committed significantly more slips and lapses as compared to expert drivers. Furthermore, an increased cognitive workload (CWL) is associated with an increase in the occurrence of slips and lapses. On the whole, the results of the study signify the importance of strict enforcement of traffic regulations related to distracted driving more stringently in the case of novice drivers.
Perceptual and Motor Skills
In-vehicle interactive systems are widely used in modern vehicles. While these systems serve vari... more In-vehicle interactive systems are widely used in modern vehicles. While these systems serve various purposes, they are also potential distracters for drivers. In this study we investigated the effect of in-vehicle spatial distractions on driving errors and driver gaze behavior by developing an experimental paradigm named, “Direction Following in Distracted Driving – Spatial: Simultaneous and Sequential (D3-SSS).” Twenty-seven drivers voluntarily participated and were required to drive an instrumented vehicle on a two-lane test-track, following directions shown on direction signboards. While driving, drivers were required to respond to in-vehicle spatial distracting stimuli presented to them through a monitor attached to the dashboard. The drivers were randomly assigned to in-vehicle spatial-simultaneous and spatial-sequential distraction conditions. Our results demonstrated that, in comparison with spatial-sequential distractions, there were shorter eye fixation durations and fewer...
Drivers get driving related information mainly through visual, auditory, and haptic sensory chann... more Drivers get driving related information mainly through visual, auditory, and haptic sensory channels but it is predominantly based on the information received through visual senses. In working memory visual information fades away faster than the auditory information and in order to retain the visual information for a longer duration it gets recoded into phonological information through Articulatory Rehearsal Mechanism (ARM) [1]. After every 2 s, ARM recites and rehearses the phonological information making it to re-enter into the phonological store, where it starts to decay again immediately [1, 2]. Individuals when engaged in processing visual information in order to perform driving and if there is suppression of ARM chances are high that visual information processing will be compromised. This distraction is ought to suppress the visual information from being rehearsed and remembered acoustically. The present study investigates the effect of suppression of ARM on driving performanc...
Transportation Research Part F: Traffic Psychology and Behaviour, 2018
This study reports development of an experimental paradigm named as ‘Direction Following in Distr... more 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 signif...