Stress and Cognitive Load in Multimodal Conversational Interactions

The quality assessment of multimodal conversational interactions is determined by many influence parameters. Stress and cognitive load are two of them. In order to assess the impact of stress and cognitive load on the perceived conversational quality it is essential to control their levels during the interaction. Therefore we present in this paper preliminary experiments carried out to determine the circumstances in which low/high levels of stress respectively cognitive load are achieved while interacting with the system. Different levels are manipulated by varying task difficulty (information complexity, task load, and simulated speech recognition errors), information presentation (modality usage, spatial organization and temporal order of information items) and time pressure. Heart rate variability (HRV) and galvanic skin response (GSR) as well as subjective judgments in the form of questionnaires are deployed to validate the induced stress and cognitive levels. Methods and preliminary results are presented.