Biometrics, Features, Game Metrics, Psychophysiology

Shoot To Thrill – Biofeedback in Games and Player Experience

I was unpre­pared when open­ing the lat­est edi­tion of favorite indus­try mag­a­zine Game Developer, when a blink on the cov­er should have already told me what was revealed on page 21 in this October 2008 issue. As my eyes went into sac­cadic over­load, I could feel my lacrimal glands kick­ing in lead­ing to an over­lu­bri­ca­tion of my cornea, which almost pre­vent­ed me from read­ing the biofeed­back arti­cle con­ve­nient­ly titled “Shoot to thrill”.

It was hard to believe at first: A major arti­cle on how the American EmSense Corporation was using biofeed­back to eval­u­ate engage­ment in games, obvi­ous­ly show­cas­ing some results from their recent stud­ies of an accu­mu­lat­ed mass of 300 hours of data (phys­i­o­log­i­cal and game­play). Ding! Ding! Did I not want to write a PhD about this top­ic? No ref­er­ence to aca­d­e­m­ic work (well, my papers might be a bit too new, but hey there is a whole crowd of game researchers, who have been into met­rics and phys­i­o­log­i­cal mea­sure­ment for a few years now)... Fighting an ini­tial state of cog­ni­tive arrest result­ing from the usu­al anx­i­ety PhD stu­dents get when they have the feel­ing that their research has already been done by some­body else, I was lat­er able to read the arti­cle in detail.

They have used a num­ber of mod­ern, most­ly first-per­son, shoot­er action games, like Battlefield 2141, Call of Duty 3, F.E.A.R., Gears of War, Ghost Recon AW 2, Resistance: Fall of Man, Halo 2, and Half-Life 2. Then, they claim to use their own pro­pri­etary head­set to mea­sure the fol­low­ing: EEG, heart activ­i­ty, breath­ing, blink­ing, tem­per­a­ture, and motion. Ok, so I am guess­ing here, that their ban­dana includes maybe four dry elec­trodes (opposed to the 32 chan­nels we usu­al­ly use in our research) and maybe also incor­po­rates gal­van­ic skin response (even though the head is not the per­fect loca­tion to mea­sure this).

The sci­en­tif­ic ques­tion that remains: How accu­rate can this be to assess the fac­tor they claim to be able to mea­sure with this? Engagement, emo­tion, adren­a­line and cog­ni­tion. I already some­times feel like I try read­ing someone’s palm when I sit in front of elab­o­rate high-res­o­lu­tion EEG data, how would it be the data were in small­er res­o­lu­tion? Although, I have to admit that I do not pos­sess equal pow­ers as a team of 7 com­mit­ted MIT grad­u­ates and they seem to use elab­o­rate algo­rithms to cal­cu­late their engage­ment pro­files. In a sigh of relief, I remind­ed myself that it is indus­try stuff that I am read­ing here, not a sci­en­tif­ic jour­nal. Therefore, giv­ing them the ben­e­fit of the doubt, I con­tin­ued to look at their find­ings:

  • Cut scenes engage play­ers only by stick­ing to a the­mat­ic emo­tion or refer­ring to char­ac­ters to which the play­er has already estab­lished emo­tion­al attach­ment. This sounds per­fect­ly rea­son­able; how­ev­er, I strong­ly won­der how they would eval­u­ate emo­tion­al attach­ment with­out tak­ing a facial EMG.
  • Tutorials are more engag­ing if play­ers expe­ri­ence real com­bat sce­nar­ios. When play­ers are threat­ened in the tuto­r­i­al phase already, they will like­ly learn the inter­ac­tion mechan­ics faster than when they have to lis­ten to an instruc­tor. They also refer to an “emo­tion­al roller­coast­er” here, a moment of calm instruc­tion is fol­lowed by intense com­bat, which is explained in the next point.
  • The alter­na­tion between brief calm moments and intense events or com­bat is keep­ing play­ers more engaged. This is a hypoth­e­sis I can com­plete­ly back up from the sci­ence side as in a study that I will be pre­sent­ing at this year’s Future Play con­fer­ence, I found that a lev­el I designed around the con­cept of sequences of com­bat in alter­na­tion with regeneration/resting elicit­ed more signs of play­ers being the flow state than a reg­u­lar lev­el. As sci­en­tists explore the con­cepts behind game expe­ri­ence and what lev­els of engage­ment are elicit­ed by what game ele­ments, I think there could be mutu­al ben­e­fit.
  • Players find close com­bat more engag­ing than shoot­ing. This I find a promis­ing premise for a future study as their argu­ment seems rea­son­able, even though I still won­der how they ass­es pos­i­tive emo­tion for a ener­gy sword kill in Halo 2, using the equip­ment they described.
  • Little good­ies in games can sum up to a gen­er­al­ly greater expe­ri­ence. This was in my opin­ion their weak­est point. As of course they were ana­lyz­ing game events in con­text, much like we do in our cur­rent stud­ies, but they only giv­ing a few exam­ples here of what those lit­tle good­ies can be (e.g. grenades in Halo 2). But what I think they are real­ly try­ing to say here is that by design­ing engag­ing sin­gle play­er com­bat, you are more like­ly to have an engag­ing mul­ti­play­er expe­ri­ence, if that builds on your sin­gle play­er com­bat mechan­ics.
  • Cut scenes need to be more Michael Bay and less Steven Soderbergh. Meaning that dynam­ic action scenes, espe­cial­ly when they involve game char­ac­ters are like­ly to be more engag­ing for play­ers than cut scenes that try to inform the play­er about some­thing.
  • Tutorials should grab you from the start. Meaning that if you are only try­ing to sim­u­late the game dur­ing the first min­utes of game­play, play­ers will like­ly be less engaged. And los­ing your play­ers in the tuto­r­i­al phase might result in your game not suc­ceed­ing at all. This sounds obvi­ous, but it is good to see it backed up by their data.
  • Too much con­stant inten­si­ty will result in detach­ment of play­er engage­ment. This is some­thing I would like to put to the test myself, as it seems an inter­est­ing hypoth­e­sis that play­ers will lose inter­est if the game is too chal­leng­ing. Getting chal­lenge opti­mal­ly right might only be pos­si­ble in the afore­men­tioned alter­na­tion between intense com­bat and cooldown areas.
  • Repetitive actions result in play­ers los­ing inter­est, so does assured out­come. This is basic wis­dom of a good game design­er, adding a ran­dom ele­ment to your games ulti­mate­ly results in more fun. Something we see in board games using dice mechan­ics every day.
  • Use of inter­est­ing weapons can have a large impact on game­play. This is a more dif­fi­cult con­clu­sion, because it is hard to gen­er­al­ize. I would say that any kind of usable item in a game that has a high nov­el­ty val­ue for the play­er is like­ly to keep them engaged as they might find the pay­off of using it a dri­ving fac­tor for game­play itself. The per­fect exam­ple of this is Portal, where the whole game­play mechan­ic was designed around a nov­el­ty weapon. I would like to study this in more detail as well.

They con­clude their arti­cle with a state­ment that I find per­fect­ly sound: The major ben­e­fit of using bio-sen­so­ry eval­u­a­tion tech­niques for games is that you can find behav­ioral trends of play­ers that allow you to esti­mate what parts of your game design are work­ing and what parts are not. This makes this kind of analy­sis an invalu­able tool for improv­ing game design. Case in point, these meth­ods will change the game indus­try for the bet­ter. With a mixed feel­ing of excite­ment and pres­sure, I will return now to ana­lyz­ing the stud­ies that con­sol­i­date my PhD. If you are into these kinds of stud­ies, next week is a great chance to catch one of my talks at Future Play in Toronto, Canada and iTec, Darmstadt, Germany. In addi­tion, all encour­age­ments for fin­ish­ing it soon are great­ly appre­ci­at­ed.


4 thoughts on “Shoot To Thrill – Biofeedback in Games and Player Experience

  1. Pingback: Player Engagement, In-Game Advertising, Neuromarketing and User Experience « The Acagamic

  2. Bryan Rayner says:

    What I want to see is them try doing a sim­i­lar test with Jason Roher’s games, or Braid, or Flower, Cloud.

    I guess it’s all com­ing back to the Theory of Fun, eh?

    Good luck with your PhD!

  3. Libby | stress relief says:

    This is a very infor­ma­tive arti­cle. I had no idea that so much thought went into the set up of the games. I just know it’s a great stress relief to play and escape.

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