Effect of a concurrent auditory task on visual search performance in a driving-related image-flicker task Professor: Liu Student: Ruby

Motivation & purpose Motivation –Using telephone on the car may affect driving performance. Purpose –To test the effect of limiting attention on the change blindness in driving-scene images. –Single-task and dual-task.

References The combination tasks has a negative effect on driving test. (Alm & Nilsson, 1994) Some on-road driving studies indicate that such as lane maintenance and braking are not significantly affected by telephone use. (Briem & Hedman, 1995) Change blindness can divided into limited attention when it is presented by an image flicker technique (Rensink, O’Regan, & Clark, 1997, 2000).

References Experienced drivers searched a larger visual area more efficiently and with fewer eye movements than novice drivers. (Crundall, Underwood, & Chapman, 1999) The auditory task was the Working Memory Span Test and used in many studies to test the divided attention on driving performance (Briem & Hedman, 1995).

Methods Participants –26 undergraduates. –Normal vision. –Driving license. Equipments –Computer and 17-inch monitor. –Viewing distance: 60 cm

Methods Stimuli –Half of the images the changed included an object to the driving. –Half of the images the changed included an object to the unrelated to the driving.

Methods Procedure –8 practice trials. –Half the trials only have the visual task. –Half the trial have the visual task and auditory task.

Methods Visual scanning task

Methods Auditory task –Contents: A B C (every letter delay 1 second.) –Ask: B before A (answer: false)

Methods Total 88 images, 22 for each task type 2 ×change type 2. –Task type: single task and dual task –Change type: driving related and driving unrelated

Results Outliers: –RT were less than 200 ms. –Participants detected the wrong objects and location. –RT were greater than 3 standard deviation from the right responds.

Results Mean response times and error rates for driving-related and driving-unrelated scene changes.

Results The main effect of change type was significant, F(1,25)=269.33, MSE= , p<.0001 The main effect of change type was significant, F(1,25)=25.60, MSE= , p<.0001 The change type × task type interaction was no significant, p=.7958

Results Speed-accuracy trade-off : (include the outliers) –The main effect of change task types significant, F(1,25)=25.47, MSE=2.60, p< –The main effect of task types (p=.4316) and the interaction (.3779) was not significant.

Results RT were significantly faster in the driving related 9.03 vs 11.78, t(31)= -2.27, p=.03. Mean response times for individual changes as a function of distance from the center of the screen.

Discussion Participants were significantly slower in both change types during the auditory task. RT should be delayed because the auditory task and during the auditory task, the participants were not stop looking the images. When the auditory task presented at the same time, it can impair the visual task.

Discussion The auditory task (second task) reduced the horizontal and vertical of the visual scanning window which can affect the participants’ ability to detect the dangerous objects. Driving related objects were detected more faster than driving unrelated objects. –The participants were used their driving experience for searching the similar scenes.

Conclusion Drivers’ attention is divided between operating a telephone and driving, visual analysis can be impaired on the road.