Capturing user engagement via psychophysiology: Measures and mechanisms for biocybernetic adaptation

The concept of task engagement is associated with effortful striving to reach a desired goal. This dimension is fundamental for software designed to elicit high quality performance. This paper will review the concept of task engagement, both in the psychological literature and with respect to affective computing approaches, such as biofeedback and the definition of 'flow' states. This paper will briefly describe a series of laboratory experiments designed to explore measures of task engagement based on EEG and cardiovascular measures. These experiments employed a number of manipulations to influence task engagement, e.g. performance feedback, task difficulty and financial incentives. Results demonstrated the sensitivity of EEG measures to cognitive sources of engagement (e.g. mental workload) whilst cardiovascular variables tended to respond to the motivation to achieve. We use these findings to explore how real-time monitoring of engagement may generate adaptive dynamics for software design using a computer game as an exemplar system.