The pupil response as an indicator of user experience in a digital exercise game.

To study whether psychophysiological indicators are suitable measures of user experience in a digital exercise game (exergame), a laboratory study employing both psychophysiological and self-report measures was conducted. Sixty-six participants cycled for 10 min on an ergometer while pupil diameter, skin conductance, and heart rate were measured; afterward, they completed a user experience questionnaire. The participants performed under three experimental conditions varying between subjects: active gaming (participants controlled the altitude of a digital bird by varying their pedal rate in order to catch letters flying across the screen), observing a game (they observed a replay of another participant's game), and no-game (blank screen). Only the gaming condition showed evidence for statistically significant pupil dilations-indicating emotional arousal-in response to game events (catching a letter) or corresponding points in time. The observational condition did not differ statistically from the no-game control condition. Self-reports also indicated that the gaming condition was rated most fun and least demanding. Other psychophysiological indicators (heart rate, skin conductance) showed no systematic effects in response to game events, rather they steadily increased during training. Thus, pupil responses were shown to be suitable indicators of positive emotional reactions to game events and user experience in a (training) game.

Personalized Adaptive Control of Training Load in Cardio-Exergames--A Feasibility Study.

OBJECTIVE: This article presents a feasibility study of using an algorithm for an individual and adaptive control of training load in an ergometer-controlled exergame for aerobic training. An additional goal was to investigate the effects of the adaptive game on the players' motivation. MATERIALS AND METHODS: A two-phase approach (calibration and exercise phase) was applied in a sample of 16 physically active adults. In the cardio-exergame "LetterBird," the flight of a pigeon was controlled by the pedaling rate of a bike ergometer as input device. During the calibration phase the individual heart rate (HR) responses of the players were measured. In the exercise phase, these data were used to adjust the resistance of the ergometer using the proposed algorithm. The purpose of this algorithm was to induce an individually defined target HR and to keep it in a steady state. In order to establish a reference for further studies, the game experience was measured using the kids-Game Experience Questionnaire. RESULTS: In 15 of 16 participants the actual HR reached the intended individual HR range within 10 minutes after onset of exercise. However, the induced HR initially exceeded the target HR in 13 participants, which made load adjustments necessary. The analysis of the kids-Game Experience Questionnaire confirmed the motivational effect of the exergame "LetterBird." CONCLUSIONS: The results confirm that the proposed algorithm for personalized HR control in the game "LetterBird" is feasible. Furthermore, the cardio-exergame "LetterBird" seems to have a substantial short-term motivating effect.