The role of attentional breadth in perceptual change detection

1
The role of attentional breadth in perceptual
change detection

• Professor Liu
• Student Ruby

2
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.

3
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)

4
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)

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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)

6
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 drivers license for 2
  years, and drove over 25 miles per month.

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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 region.

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Method perceptual change task

• Each image was displayed for 240 msec and each
  blank screen for 80 msec.
• 80 photographs were taken from the drivers 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.

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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
  printed 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 importance of
  the change to driving performance.
• Salience was defined to noticeable change should
  be the high salient.

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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.

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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.

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Method atentional breadth task

• An oblique target appearing in 11 vertical
  distractors.
• Targets and distractors appear randomly at one 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.

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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, Plt0.001.
• Eccentricity central changes were detected more
  quickly than peripheral ones, F(1,48)35.14,
  Plt0.001.
• Meaningfulness low 9, high 8.2 sec
  F(1,48)9.65, Plt0.003.
• Salient low 10.9, high 6.8 sec
  F(1,48)313.93, Plt0.001.

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Results change detection performance (RT)

• A significant two-way interaction was between age
  and salience, F(1,48)6.53, plt0.014.
• This result is not found in the previous
  literature.
• The age and eccentricity interaction was no
  significant.
• It may because didnt control the eye movements.

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Results change detection performance (RT)

• The three-way interaction between age,
  meaningfulness, and salience. F(1,48)7.94,
  Plt0.007.
• 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.

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Results change detection performance (RT)

• A significant three-way interaction was also
  found between eccentricity, meaningfulness, and
  salience. F(1,48)9.64, Plt0.003.
• 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.

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Results change detection performance (accuracy)

• Main effects were significant for
• Age F(1,38)39.8, Plt0.001
• Eccentricity F(1,38)31.7, Plt0.001
• Salience F(1,48)64, Plt0.001

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Results change detection performance (accuracy)

• Two-way interactions was found for age
  salience. F(1,48)19.3, plt0.001
• Also found significant two-way interactions for
  meaningfulness salience. F(1,48)4.7, Plt0.03
  

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Results relationship between FFOV and change
detection performance

• A larger FFOV correspond to faster detection of
  object changes. (r-0.68, plt0.001)

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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 (plt0.01), for centrally
  located changes.
• The correlation was -0.66 (plt0.01), for periphery
  located changes.

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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.

22
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.

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Discussion attentional breadth and change
detection

• A strong correlation between breadth of attention
  and change detection.
• A smaller FFOV corresponded to slower change
  detection.
• The breadth of attention plays an important role
  in change detection.
• Reducing the number of attentional samples
  required to detect a change.