Manipulating Attention in Computer Games

Matthias Bernhard, Le Zhang,

Michael Wimmer

Institute of Computer Graphics and Algorithms

Vienna University of Technology

Attention without a Task

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Attention

Stimulus

But during Game Play...

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Attention

Stimulus

Attention only to Task

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Attention

Stimulus

task-relevant

Inattentional Blindness

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Attention

Stimulus

not attended

Manipulating Attention

Why ? Control difficulty of a game

Decrease or increaseAvoid Inattentional Blindness

Notify user about unexpected, but important information

Visibility of advertisements How ?

Influence preattentive vision Increase saliency

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Increasing Saliency

Bottom-up / Stimulus driven :Contrast, warm colors, high

luminance,... Changes: motion, flicker, ... Previous work !

Top-down biased:During visual search tasks This work !

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This Work

Simple but effective guiding principle Manipulate attention during a task Preliminary evaluation with a user study

Action computer gameDirect attention towards an advertisement

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Increasing Bottom-Up Saliency

Intelligent lighting [El-Nasr 2005]Techniques used in theatres and movies

h

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El-Nasr, M.S., Intelligent Lighting for Game Environments, Journal of Game Design, 2, 1 (2005)

Increasing Bottom-Up Saliency

Subtle Gaze Direction [Bailey et al. 2008]Subtle modulation in

peripheral FOVStop modulation

before fixationEye-tracker required

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Bailey,R,McNamara,A.,Sudarsanam,N.,Grimm,C., Subtle Gaze Direction, ACM Transactions on Graphics,, 28, 4 (2008)

Modulation

Problem: Inattentional Blindness

Bottom-up saliency not necessarily sufficient Strong focus on task, particularly in games

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Increasing Top-Down Biased Saliency

Guided Search [Wolfe 1994]Top-down influence during visual searchBias towards features of a search targetMany search tasks in games

Our proposal:Generate distractors of g. search itentionally Adjust design of search targets

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Advertisements Unattended

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Attention

health item

Change a Search Target

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Attention

Advertisement Becomes Distractor

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same featuresAttention

Advertisement Becomes Distractor

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similar color

same featuresAttention

User Study with Computer Game

2D action game with 3D background

6 advertisements in background1 distractor adv. + 5 other adv.BichromaticReal brands Realistic lighting

(raytraced scene)

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Game elements

Background scene

Procedure

Play game (3 minutes) Distraction (6 minutes) Memory Test

Recognition test3 alternatives/forced choice1 in-game advertisement

+ 2 not in game adv.Select with mouseclick36 trials: 6 per advert.

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Game

Memory test application

Test Group (12 Participants)

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expectedattention

distractor

target

Control Group 1 (N=12)

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expectedattention

target

Control Group 2 (N=12)

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expectedattention

target

replaced

Results: Distractor Advertisement

Around chance level in control groups

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Test

Control 1

Control 2

pro

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corr

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Results: Distractor Advertisement

Around chance level in control groups Difference betw. test and controls: p<0.001 (Wilcox)

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Test

Control 1

Control 2

pro

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***

Results: Other Advertisements

Also higher scores in test group

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Test

Control 1

Control 2

pro

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corr

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Results: Other Advertisements

Also higher scores in test group One possible reason: similarity of color

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Test

Control 1

Control 2

pro

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corr

ect

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similar color

Results: Other Advertisements

Interesting: difference betw. Test & Control 2 Generally increased attention to background ?

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Test

Control 1

Control 2

pro

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corr

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p=.12

p=.14

Conclusion Control group:

Advertisements not remembered well (also salient ones!!!)

Inattentional Blindness did occur Bottom-up saliency necessary, but not sufficient

Test group:We „broke through“ Inattentional BlindnessProbably increased attention to other

background elements too

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Future work

More studiesMultivariate analysisSubtle feature combinationsDynamic viewpointEye-tracking

Visualization tool for game designers Encode current task in visual search tasksComputational simulation of Guided Search Related work: Navalpakkam and Itti, „Modelling the

Influence of Task on Visual Attention“, Vis.Research, 2005

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Thanks for your attention !

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Variation across Participants

Distribution visualized with box plots

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pro

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Increasing Bottom-Up Saliency

Use pop-out features Shrill colors, brightness, etc

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© Ghostbusters: The Video Game