Download - LOGO The role of attentional breadth in perceptual change detection Professor: Liu Student: Ruby
LOGO
The role of attentional breadth in perceptual chan
ge detectionProfessor: LiuStudent: Ruby
Objective
• Examined the relationship between perceptual change detection and attention which relating individual differences in attentional breadth to observers’ ability to detect changes in driving scenes.
References
• When changes to scenes at the same time with saccadic eye movements, we have a limited ability to detect them.
(Grimes, 1996; Henderson, 1997; McConkie & Currie, 1996)
• The objects of central interest probably attracted attention through higher level cognitive processes.
(Rensink et al. 1997)
References
• The FFOV represents the spatial area that is needed to perform a specific visual task without occurred eye or head movements. (Ball, Roenker, & Bruni, 1990; Mackworth, 1965, 1976)
• The size of the FFOV decreased with age.
(Ball, Beard, Roenker, Miller, & Griggs, 1988)
References
• Older drivers had poorer driving performances on the FFOV, a skill that would seem to because an ability to detect change in the environment.
(Isler, Parsonson, & Hansson, 1997; Rizzo, Rinach, McGehee, & Dawson, 1997)
Method - participants
• 25 Younger group• 13 women, 12 men.• Age from 18 to 33 years.
• 26 Older group• 18 women, 8 men.• Age from 55 to 80 years.
• Each participant had corrected visual acuity better than 20/40.
• Each participant had a driver’s license for 2 years, and drove over 25 miles per month.
Method - apparatus
• A Micron Millenia MME computer.
• A 12 × 16in. Viewsonic monitor.• 56 cm from the screen.
• A Fresnel lens.• Was used to remove the accommodation cues.• Increased the subjective size of the image regi
on.
Method – perceptual change task
• Each image was displayed for 240 msec and each blank screen for 80 msec.
• 80 photographs were taken from the driver’s view inside a car.
• The objects and their changes were categorized along three parts: eccentricity, meaningfulness, and salience.
• When they detected the change, press the mouse button and describe the change.
Method – perceptual change task
• The first pilot study (meaningfulness and salience)• 14 younger and 10 older participants.• Subjects saw two images of a scene on color p
rinted pages in a notebook. (82 scenes)• They were asked to rate the change according
to a 6 point Likert scale.• Meaningfulness was defined to the importa
nce of the change to driving performance.• Salience was defined to noticeable change
should be the high salient.
Method – perceptual change task
• The second pilot study (meaningfulness and salience)• 6 younger and 6 older participants.• Rate a single object in each of the 82
scenes.• Meaningfulness was defined to the
importance of the object to driving performance.
• Salience was defined to noticeable object should be the high salient.
Method – perceptual change task
• The perceptual change performance, the 80 driving scenes were divided into four categories:• Low meaning/low salience.• Low meaning/high salience.• high meaning/low salience.• high meaning/high salience.
Method – atentional breadth task
• An oblique target appearing in 11 vertical distractors.• Targets and distractors appear randomly at on
e of three eccentricities (10, 20, and 30 deg from fixation) along 8 radial meridians for a total of 24 possible positions.
• After finish the change detection task, they moved the mouse to one of the 24 possible target positions to indicate their response.
Results – change detection performance (RT)
• Main effects were significant for all four factors.• Age: younger adults performed
significantly faster than older adults, F(1,48)=41.02, P<0.001.
• Eccentricity: central changes were detected more quickly than peripheral ones, F(1,48)=35.14, P<0.001.
• Meaningfulness: low = 9, high = 8.2 sec; F(1,48)=9.65, P<0.003.
• Salient: low = 10.9, high = 6.8 sec; F(1,48)=313.93, P<0.001.
Results – change detection performance (RT)
• A significant two-way interaction was between age and salience, F(1,48)=6.53, p<0.014.• This result is not found in the previous
literature.
• The age and eccentricity interaction was no significant.• It may because didn’t control the eye
movements.
Results – change detection performance (RT)
• The three-way interaction between age, meaningfulness, and salience. F(1,48)=7.94, P<0.007.• Increase
meaningfulness had no effect on performance for either age group when changes were highly salient.
• When salience change was low, increasing meaningfulness help the performance of young, but not old.
Results – change detection performance (RT)
• A significant three-way interaction was also found between eccentricity, meaningfulness, and salience. F(1,48)=9.64, P<0.003.• When changes were
both high meaning and salience, the central changes were detected faster than peripheral changes.
• Different meaningfulness did not influence performance when changes were both peripheral and low salience.
Results – change detection performance (accuracy)
• Main effects were significant for:• Age[ F(1,38)=39.8, P<0.001 ]• Eccentricity[ F(1,38)=31.7, P<0.001 ]• Salience [ F(1,48)=64, P<0.001 ]
Results – change detection performance (accuracy)
• Two-way interactions was found for age × salience. [ F(1,48)=19.3, p<0.001 ]
• Also found significant two-way interactions for meaningfulness × salience. [ F(1,48)=4.7, P<0.03 ]
Results – relationship between FFOV and change detection performance
• A larger FFOV correspond to faster detection of object changes. (r=-0.68, p<0.001)
Results – relationship between FFOV and change detection performance
• The size of the FFOV appear to be related to change detection for central changes and perhaps even more strongly for peripheral changes.
• The correlation was -0.54 (p<0.01), for centrally located changes.
• The correlation was -0.66 (p<0.01), for periphery located changes.
Discussion – age, change characteristic, and change detection.
• Salient scene characteristics were more responsible for driving attention to change than meaningful change characteristics, especially for older adults.
• The salient changes to objects are quickly detected, but nonsalient changes are detected by slow, serial processing.
Discussion – age, change characteristic, and change detection.
• Older drivers had more difficulty detecting change under most situations adds a new dimensions to the present literature on change detection.• Older and younger drivers showed
differences in detecting changes, but not unsurprising given other findings for age-related differences on many visual search tasks.
Discussion – attentional breadth and change detection
• A strong correlation between breadth of attention and change detection.• A smaller FFOV corresponded to slower chang
e detection.• The breadth of attention plays an impo
rtant role in change detection.• Reducing the number of attentional samples r
equired to detect a change.