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 Matthias Bernhard, Le Zhang, Michael Wimmer 1 Attention Stimulus

But during Game Play... Matthias Bernhard, Le Zhang, Michael Wimmer 2 Attention Stimulus

Attention only to Task Matthias Bernhard, Le Zhang, Michael Wimmer 3 Attention Stimulus task- relevant

Inattentional Blindness Matthias Bernhard, Le Zhang, Michael Wimmer 4 Attention Stimulus not attended

Manipulating Attention  Why ?  Control difficulty of a game  Decrease or increase  Avoid Inattentional Blindness  Notify user about unexpected, but important information  Visibility of advertisements  How ?  Influence preattentive vision  Increase saliency Matthias Bernhard, Le Zhang, Michael Wimmer 5

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 ! Matthias Bernhard, Le Zhang, Michael Wimmer 6

This Work  Simple but effective guiding principle  Manipulate attention during a task  Preliminary evaluation with a user study  Action computer game  Direct attention towards an advertisement Matthias Bernhard, Le Zhang, Michael Wimmer 7

Increasing Bottom-Up Saliency  Intelligent lighting [El-Nasr 2005]  Techniques used in theatres and movies h Matthias Bernhard, Le Zhang, Michael Wimmer 8 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 FOV  Stop modulation before fixation  Eye-tracker required Matthias Bernhard, Le Zhang, Michael Wimmer 9 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 Matthias Bernhard, Le Zhang, Michael Wimmer 10

Increasing Top-Down Biased Saliency  Guided Search [Wolfe 1994]  Top-down influence during visual search  Bias towards features of a search target  Many search tasks in games  Our proposal:  Generate distractors of g. search itentionally  Adjust design of search targets Matthias Bernhard, Le Zhang, Michael Wimmer 11

Advertisements Unattended Matthias Bernhard, Le Zhang, Michael Wimmer 12 Attention health item

Change a Search Target Matthias Bernhard, Le Zhang, Michael Wimmer 13 Attention

Advertisement Becomes Distractor Matthias Bernhard, Le Zhang, Michael Wimmer 14 same features Attention

Advertisement Becomes Distractor Matthias Bernhard, Le Zhang, Michael Wimmer 15 similar color same features Attention

User Study with Computer Game  2D action game with 3D background  6 advertisements in background  1 distractor adv.  + 5 other adv.  Bichromatic  Real brands  Realistic lighting (raytraced scene) Matthias Bernhard, Le Zhang, Michael Wimmer 16 Game elements Background scene

Procedure  Play game (3 minutes)  Distraction (6 minutes)  Memory Test  Recognition test  3 alternatives/forced choice  1 in-game advertisement + 2 not in game adv.  Select with mouseclick  36 trials: 6 per advert. Matthias Bernhard, Le Zhang, Michael Wimmer 17 Game Memory test application

Test Group (12 Participants) Matthias Bernhard, Le Zhang, Michael Wimmer 18 expected attention distractor target

Control Group 1 (N=12) Matthias Bernhard, Le Zhang, Michael Wimmer 19 expected attention target

Control Group 2 (N=12) Matthias Bernhard, Le Zhang, Michael Wimmer 20 expected attention target replaced

Results: Distractor Advertisement  Around chance level in control groups Matthias Bernhard, Le Zhang, Michael Wimmer 21 Test Control 1 Control 2 proportion correct answers

Results: Distractor Advertisement  Around chance level in control groups  Difference betw. test and controls: p<0.001 (Wilcox) Matthias Bernhard, Le Zhang, Michael Wimmer 22 Test Control 1 Control 2 proportion correct answers ***

Results: Other Advertisements  Also higher scores in test group Matthias Bernhard, Le Zhang, Michael Wimmer 23 Test Control 1 Control 2 proportion correct answers

Results: Other Advertisements  Also higher scores in test group  One possible reason: similarity of color Matthias Bernhard, Le Zhang, Michael Wimmer 24 Test Control 1 Control 2 proportion correct answers similar color

Results: Other Advertisements  Interesting: difference betw. Test & Control 2  Generally increased attention to background ? Matthias Bernhard, Le Zhang, Michael Wimmer 25 Test Control 1 Control 2 proportion correct answers 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 Blindness  Probably increased attention to other background elements too Matthias Bernhard, Le Zhang, Michael Wimmer 26

Future work  More studies  Multivariate analysis  Subtle feature combinations  Dynamic viewpoint  Eye-tracking  Visualization tool for game designers  Encode current task in visual search tasks  Computational simulation of Guided Search  Related work: Navalpakkam and Itti, „Modelling the Influence of Task on Visual Attention“, Vis.Research, 2005 Matthias Bernhard, Le Zhang, Michael Wimmer 27

Thanks for your attention ! Matthias Bernhard, Le Zhang, Michael Wimmer 28

Variation across Participants  Distribution visualized with box plots Matthias Bernhard, Le Zhang, Michael Wimmer 29 proportion correct answers

Increasing Bottom-Up Saliency  Use pop-out features  Shrill colors, brightness, etc Matthias Bernhard, Le Zhang, Michael Wimmer 30 © Ghostbusters: The Video Game