Transcript The Effects of Varied Peripheral and Central Changes on Change

The Effects of Focused Attention
and Varied Peripheral and Central
Changes on Change Blindness
and Change Detection
Teal Maxwell
Emily Welch
Naomi Janett
Jessica Padgett
Defining Terms
Change Blindness
 Change Detection
 Focused Attention

Previous Research
Type of Change

Central changes were very frequently
detected, but peripheral changes were rarely
detected unless the participants’ attention
was directed to the peripheral images
(Turatto, Angrilli, Mazza, Umilta, & Driver
2002).
 Peripheral changes take longer to detect
(Shore & Klein, 2000).
Previous Research
Area of Focus

Usually details of an image can only be
remembered if one’s attention is focused on
the feature that is changing
(Rensink,O’Regan & Clark 1997).
 Cueing participants to the area of change
substantially increases their ability to detect a
change (Turatto, Angrilli, Mazza, Umilta, &
Driver 2002).
Variables

Independent
» Type of Change (Central or Peripheral)
» Area of Focus (Central, Peripheral, or None)

Dependent
» Number of Correctly Identified Changes (out of 5)
Hypothesis

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
Central changes will be more easily detected than
peripheral changes
With attention guidance more changes will be
detected
Participants in the condition with central changes and
centrally focused attention will correctly detect more
changes than the other experimental conditions
Method
Participants

200 total participants
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31 Central Change and Central Focus
37 Central Change and Peripheral Focus
37 Central Change and No Focus
30 Peripheral Change and Central Focus
30 Peripheral Change and Peripheral Focus
35 Peripheral Change and No Focus
Female Mount Holyoke College
students
 Random assignment

Materials
2 photos per condition (6 total
conditions)
 Photos taken by an Olympus digital
camera

Materials
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Pictures printed on a 8.5” x 11” sheet of paper
Changes detected were reported on 3” x 5”
notecard
Stopwatch used for timing
Consent form
Debriefing statement
Procedure

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Participant signed consent form
Participants given notecard
Directions read depending on condition
Original photo shown for 30 seconds
5 second pause
Modified photo shown for 30 seconds
Participants recorded changes detected
Debriefing statement presented
Original
Central
Original
Peripheral
Original with Focus
Central with Focus
Original with Focus
Peripheral with Focus
Results
Dependent Variable

The number of correctly detected
changes out of a possible 5
Hypothesis



Central changes will be more easily detected than
peripheral changes
With attention guidance more changes will be
detected
Participants in the condition with central changes and
centrally focused attention will correctly detect more
changes than the other experimental conditions
Results
Analysis
Data were analyzed using a two-way
independent groups ANOVA
 Central changes

» Mean: 3.03
» Standard Deviation: 1.63

Peripheral changes
» Mean: 1.71
» Standard Deviation: 1.41

Results significant, p <.001
Changes Detected
Main Effect - Type of Change
5
4
3
2
1
0
Central
Peripheral
Type of Change
Results
Analysis

Central focus
• Mean: 2.56
• Standard Deviation: 2.22

Peripheral focus
• Mean: 1.89
• Standard Deviation: 1.23

No focus
• Mean: 2.74
• Standard Deviation: 1.33
Changes
Detected
Main Effect - Attention Guidance
5
4
3
2
1
0
Central
Peripheral
Attention Guidance
None
Results
Analysis

Central Change-Central Focus

• Mean: 4.56
• Standard Deviation: 0.57

Central Change-Peripheral
Focus
• Mean: 0.5
• Standard Deviation: 1.14

• Mean: 1.43
• Standard Deviation: 1.28

Central Change-No Focus
• Mean: 3.35
• Standard Deviation: 1.03
Peripheral Change-Central
Focus
Peripheral Change-Peripheral
Focus
• Mean: 2.47
• Standard Deviation: 0.90

Peripheral Change-No Focus
• Mean: 2.09
• Standard Deviation: 1.31
Results significant at p <.001 level
Interaction: Change and Focus
5
Num ber of Correct Changes
4.5
4
3.5
3
Central Change
2.5
Peripheral Change
2
1.5
1
0.5
0
Central
Peripheral
None
Area of Focused Attention
Discussion
Main Effect One

Participants in the central condition correctly
detected significantly more changes than
participants in the peripheral condition.

Central changes are detected more
frequently (Turatto, et al. 2002).
Discussion
Main Effect Two

Participants who received central attention
guidance or no attention guidance detected
significantly more changes than those
receiving peripheral guidance.

When attention is focused on the central
aspects of an image, changes are detected
more frequently than when no guidance is
given (Turatto, et al. 2002).
Discussion
Interaction

For central changes
– those who received central attention guidance performed better
than those receiving peripheral or no attention guidance
– those who received no attention guidance performed better than
those receiving peripheral attention guidance

For peripheral changes
– those who received peripheral attention guidance correctly detected
more changes than those receiving central or no attention
guidance.
– those who received no attention guidance correctly detected more
changes than those receiving central attention guidance
Discussion
Interaction - Previous Research

When attention is directed to the area in
which the change is taking place, the change
is more likely to be detected (Turatto, et al.
2002).
 Without attention guidance, new stimuli
“overwrite” what is stored in visual memory
(Rensink, et al. 1997).
Discussion
Implications
Central changes are more often
detected than peripheral changes
 Attention is naturally focused centrally
 Attention plays a role in change
detection
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Questions?
THE
END