Company Logo Professor: Liu student: Ruby The role of working memory, field dependence, visual search, and reaction time in the left turn performance of older female drivers

Company Logo Objective To find the contribution of field dependence. visual search skill. working memory. reaction time. Two aspects of left turn performance in a group of female drivers: decision time gap choice

Company Logo References Old age drivers was 3.8 times accident. (more than 75 years old) Middle age drivers was 1.8 times accident. (44-40 years old) Young age drivers was 3 times accident. (16-19 years old) (Massie et al., 1995)

Company Logo References Close to 40% of fatalities and 60% for injuries to more than 64 years old driver occur at intersections and most of accidents in the left turns (Hauer, 1988), especially for older female drivers (Bishu et al., 1991). Drivers were shown a lack of comprehension of protected left turns (left turn on arrow only). (Knoblauch et al., 1995)

Company Logo References Misjudgment of the distance or speed of an oncoming vehicle (Scialfa et al, 1987) or misjudgment of gaps (Stamatiadis et al., 1991), which were attributed of the intersections. Greater field dependence to be related to slower recognition speeds for traffic signs. (Fleury, 1994; 1996), (Loo, 1978)

Company Logo References Greater field dependence to be related to drivers’ pedal response errors at intersections. (Grubb, 1992) When scanning a visual field, field dependence drivers are more likely to have difficulty distinguish between relevant and irrelevant.  field dependence drivers may not take the large information.

Company Logo References The dynamic acuity was predictive of driving problem. (Laux and Brelsford, 1990)  over curb, near crash due to failure to see another car. Visual acuity has also been associated with left turn decisions. (Grubb, 1992; Guerrier et al., 1995) Older drivers’ slower response rates increased their difficulties in judging time to collision and acceptable gaps. (Staplin and Lyles, 1991)

Company Logo References Older drivers’ visual information processing ability was bad, which measured by the useful field of views (UFOV). (Owsley, Sloane et al, 1991) Older persons on the visual spatial information display showed less accurate at keeping track of a single attribute of different objects. (Detweiler et al., 1996)

Company Logo Method Participants 26 women, age from years old. (M=73.35, SD=7.4) All subjects have driver license and still driving. Material Ten film of oncoming traffic at a four lane intersection. Speed limit of 30 mile/h. Presented on a TV monitor.

Company Logo Independent variables Visual acuity Used a Snellen Eye Chart to test subjects. Demographic Question about the participants' age, the number of days they drove … 28 questions about their driving experiences. Perceptual style Used the Embedded Figures Test (EFT) to measure participants’ perceptual sytle.

Company Logo Independent variables Visual search The targets were ],#,and,> which embedded in any of the locations in the search field. Working memory Participants solved the continue additions. The additions consisted of two digit number. Reaction time Simple reaction time 10 presentation of a Whit band on a black background. Choice reaction time 20 random presentations of a circle (press C) or a square (press S) on the monitor.

Company Logo Dependent variables Decision time The first frame of the scenario is displayed to the participant pressing any key on the keyboard (the gap chosen). Gap chosen The space the participant selected between two oncoming cars to do the left turn.

Company Logo Equipments BCD Video Link Control presentation of the film. IMB PC Control the BCD program. 13’’B/W monitor Connect to the VCR through the BCD interface.

Company Logo Results Participants have been driven for an average of 46 years old. They drove an average of 6 days a week. 5 reported usually driving at night. The reasons reported for not driving at night were related to vision.

Company Logo Results Relationship of age to other independent variables. Visual search skill was significant. (r (26) =-0.39, p =0.03) Relationship of working memory, visual search, field dependence, and reaction time to left turn performance. The quicker the driver’s choice reaction time, the larger the gaps chosen. The greater the working memory, the longer the driver waited.

Company Logo Results Decision time Decision time was significant related to gap sizes (r (26) =0.70, p <0.001)  the longer decision time the larger the gaps chosen.

Company Logo Results Contribution of working memory, visual search, field dependence, and reaction time to decision time, and gap choice. Decision time The greater working memory was related to longer decision time and greater field independence was related to shorter decision time.

Company Logo Results Contribution of working memory, visual search, field dependence, and reaction time to decision time, and gap choice. Gap choice Choice reaction time to contribute the most variance to left turn performance (R (1,24) =0.38, p =0.06) Decision time is the best predictor of gap choice. (R (1,24) =0.7, p <0.0001)

Company Logo Results Effects of working memory, field dependence, and choice reaction time and gap choice. Working memory plays the most important role on gap choice.

Company Logo Discussion The relationship of working memory to gap choice in this study.  greater working memory capacity would allow the older driver to manage the relevant information more efficiently.  would result in faster decision time and larger gaps. The longer decision time by high working memory.  because person being capable of managing larger amounts of information may spend more time gather relevant information.  the recognition of a traffic pattern which resulted in the strategy taken.

Company Logo Discussion A relevant parallel to driving in the intersections designing which decrease the information processing load of older drivers. Focusing on working memory would be idea to help safe driving for older persons.