This document summarizes a presentation given by Andrew Dekker from the University of Queensland and Erik Champion from Massey University in New Zealand at UX Australia 2010 in Melbourne. The presentation discussed using biometric feedback devices to adapt computer games dynamically based on a user's physiological responses. It provided examples of games that have used biometric data like Emotiv and Neurosky devices. A study was described that used a biometric sensor with a first-person shooter game to detect users' galvanic skin response, heart rate and body temperature to trigger different game events based on their stress levels. The presentation concluded by discussing the potential for biometric feedback to create more engaging adaptive gaming experiences.
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Biofeedback for blood sweat and fears: Using biometric data to dynamically adapt computer games
1. Biofeedback for blood sweat
and fears
Andrew Dekker, ITEE, University of Queensland
Erik Champion, Massey University, New Zealand
UX Australia 2010
Melbourne, Australia, 25-27 August 2010
2. Biofeedback for blood sweat
and fears
Andrew Dekker, ITEE, University of Queensland
Erik Champion, Massey University, New Zealand
UX Australia 2010
Melbourne, Australia, 25-27 August 2010
3. dynamic, adaptive and user
centric environments
computer games context
computers cannot
understand the user...
or can they?
real-time biometric devices
4. “ we are investigating the
methods that dynamically
allow a game to react and
adapt to the user through
low-cost and easily
modifiable prototypes
20. Liked
Horror
User Gamer? Played FSP? Played HL 2? Games/films?
• Aged between 15 and 50.
• Both female and male (25% female, 75% 1 casual yes no neutral
male).
2 casual yes yes neutral
• Experienced and not experienced in first
person shooters and Half-Life 2. 3 no yes yes yes
• Had not been previously involved in the 4 yes yes yes yes
project or performed informal evaluation.
• Enjoyed and didn’t enjoy horror computer 5 yes yes yes yes
games, movies and books. 6 no yes no neutral
• Had various levels of computer game
experience (from users who rarely played 7 no yes yes no
computer games to users who played games
as a hobby). 8 casual yes no yes
9 casual yes yes yes
10 no yes no yes
11 yes no no no
12 no yes no yes
13 yes yes yes neutral
14 yes no no neutral
Yes 5 12 7 7
Neutral 4 - - 5
No 5 2 7 2
Total 14 14 14 14
Dekker? Traditional game versus biometric enhanced game Every player gets the same experience, versus customised experience
Dekker? Making the game context sensitive Games like black & white started this with weather
Dekker? We examined game engines Lots of potential, especially in third person where you can see the avatar First person - the visceral reaction
Erik Wired for sound - overkill? Created based on a proprietary analysis of how users react to situations. So each biometric device must be analysed in a specific way. Another issue with these devices is that they are custom built and used solely within a single testing environment, and are generally built to only satisfy institutional and controlled ethical procedure. EEG devices involve ethical issues, and there is no scientific proof in how emotional information can be measured correctly (Beckhaus et al, 2004).
Erik? - Types of biometric interaction Heart rate can be measured in real-time through a device that measures the EKG and heart rate variability of an individual. This is accomplished through sensors that measure the rate at which blood flows through the body.Through this technique, is it possible to evaluate (with additional information) whether the user is relaxed, nervous, challenged, bored, sleepy, lying or telling the truth, as well as anxiety levels (Beckhaus et al, 2004).Additionally it is possible to measure Blood Volume Pulse (BVP) through sensors that measure blood pressure as waveform. Arousal is the prominent effect that can be measured through this application (Beckhaus et al, 2004). Wild Divine (2004) uses EKG to measure stress, respiratory and anxiety levels of the user.
Erik Neurosky and Emotiv
Erik - Devices 1? Lightstone The Lightstone measures the ECG HRV (Electrocardiogram Heartrate Variability) and the GSR (Galvanic Skin Response) of the user in real-time. Can measure: Anxiety and stress Relaxation and meditation Tension Sudden changes in mood Breathing variability
Dekker - The Data Heartbeat, Heart speed variability, Skin Response All interaction between the user and the environment is conducted through the game avatar, creating a sense of virtual ‘presence’.Presence is defined as “a state of consciousness, the sense of being in the virtual environment” (Slater et al, 1995). Presence can be further refined to personal presence, “the subjective feel of actually ‘being’ in the virtual environment, leading to a sense of “places visited, rather than seen” (Burdford and Blake, 1999). Readings are averaged at two-second intervals. This reduces any possible incorrect readings, and provides an accurate representation of the user at the particular time. The current average of the users biometrics are then compared against the calibration average, to create a multiplier. These three multipliers (heartrate variability, skin response and heartbeat) are used to dynamically change the game environment.
Dekker - Half-Life 2 Lots of technical reasons Ravenholm - horror, good for reading biometric data :)
Dekker Go through video :>
Dekker Hawthorne Effect (placating the interview). Placebo Effect (with wearing the biometric device).External environment.Technical inconsistencies.
Dekker - Avatar speed based on the heartbeat multiplier with a base level of 200. Environment volume dynamically changed based on a base level volume of 1 multiplied by the square of the players skin response, which is multiplied by 0.8. Screen fades to white if the user’s heartbeat multiplier is under 0.2 of the average.Screen fades to red if the heartbeat multiplier is over 3.5.Avatar invisibility if the users heartbeat is under 0.5 and their skin response in under 0.5 of the calibration average. Screen bright red if the user’s heartbeat and skin response are over 3 times their average, the field of view of the avatar changes to 130 degrees and the speed of the avatar dramatically increases (berserker mode). A ‘bullet time’ effect if the user’s skin response is higher then 3 times their calibration average. This effect changes the density and gravity of the environment, to emulate the effect of the avatar being faster than other characters. A red filter if the players heartbeat is faster than 2 times the average. This is to give the effect that the user is getting more excited or anxious. Screen turns black and white if the user’s heartbeat is under 0.8 of their calibrated average,Environment (walls) becomes semi-transparent if the user’s galvanic skin response is between 0.5 and 0.7 of their average.Screen shakes if the user’s heartbeat increases past 3.8 of their average.Weapon damage dynamically changes through changes in heartbeat and skin response).
Shaders - method to manipulate the visual response without requiring a lot of time / effort.
Dekker - Interface User preference of game genre, theme and style of game. Learning curveHCI problems with device Preconceptions of prototypes Design and pace of the levelDynamic events within the environment. Being killed and other immersion breaking events.
Dekker - 14 Users Do you consider yourself a gamer? Do you enjoy, or have you played First Person Shooter games? Have you played Half-Life 2? Do you enjoy horror games, films or books? What do you enjoy about them? Did you enjoy the first level you played, or the second level? Why did you enjoy one level over the other? Did you realise which level was incorporation your biometric information? Did you like or dislike the visualisation effects that were present in theenhanced level, what did you like or not like about them?What other game elements did you find different between the two levels, did they aid or hinder the game experience? What other game elements do you think may be enhanced through incorporating biometric information?From your experiences in the prototype, do you feel that biometric information can assist in creating a more engaging experience?
Dekker - Analysis All timestamped 3 things: game recordings (game play) video recordings (physical reaction) biometric logs (quantitative data)
Observation of the participant playing each level (Level A and Level B).Video recording of the players’ faces to gauge reaction to events. A recording technology that is built in to the game so that their actions within the game world could be used for reflection.Biometric recordings of the participants heartbeat, heartrate and skin response value.Interviews with the participant (which were recorded), discussing what the participant experienced during the game.
Responses to the biofeedback Lots of potential overall according to qualitative feedback
The biometric sensors created a major usability issue in the prototype. The keyboard and mouse combination were effective for most users. The interface allowed users to easily start and change the game levels. The calibration period which did not allow the user to move gave an accurate base level. The biometric sensors were reasonably effective in reading biometric information, although unbelievable readings were sometimes experienced. Users not familiar with the game genre (First Person Shooters) were move involved with learning how to play the game rather than the gameplay. The game level (Ravenholm) led to some confusion during exploration due to its open nature. Some weapons in the game were confusing to users unfamiliar with the game. Users facial expressions were easily comparable to the biometric information. When the user was killed in the game, their concentration and engagement was hindered significantly. Audio effects had a considerable effect on users biometric information and reactions. The black and white visualisation made users calmer. The red filter visualisation did not effect biometric information significantly. The white screen visualisation made users confused. Users seemed to be more engaged in the enhanced version especially when sounds were played. The learning of the environment was a major variable in the evaluation. Users’ assumptions of both environments reacting similarly was a variable not originally considered. Users reacted strongly when the screen shook. The variation of the biometric information gave very different experiences to individuals. Users did not try to adjust their breathing or heartrate to see how it affected the gameplay.The brightness of the room (camera requirements) and other factors affected the user experience.
What are the implications? biometrics allow us to better gauge the users reaction to what we do currently we have tested in a game environment games are different to a lot of forms of interactive media, they initiate interaction with the user, rather than just respond there is a lot of potential, and commercially adoption is coming slowly adaptive interfaces have a lot of potential