Sophie Stellmach of the Department of Simulation and Graphics at Otto-von-Guericke University, Magdeburg, wrote a thesis on creating a psychophysiological logging system for a digital game modification

Abstract
This student thesis intends to facilitate cognitive experiments for gameplay experience studies. To achieve this a psychophysiological logging framework was developed, which automatically reports the occurrence of specific game events to a log file and to the parallel port. Via the parallel port the communication with psychophysiological systems is possible.

Thus, psychophysiological data can be correlated with in-game data in real time. In addition, this framework is able to log viewed game objects via an eye tracker integration. This gives some information on how certain game elements affect the player's attention. For the development of this system the Source SDK, the game engine of Half-Life 2, has been used. Consequently, custom-built Half-Life 2 levels had to be developed, which are suitable for cognitive experiments. In this context, tools for level editing will be introduced.

This thesis shapes the basis for further research work in the area of psychophysiological software development and is intended to facilitate this for future scholars facing these issues.

Download Stellmach's thesis [PDF].