Stephan Streuber

The general aim of my PhD project is to investigate the perceptual and cognitive mechanism underlying joint action coordination (e.g. playing a tennis game or handing over an object to another person). Specifically I am interested in the importance of different sources of visual information (e.g. about biological motion, tools or interaction objects) and the factors which determine the use of visual information in joint actions (e.g. expertise, social context). In order to provide a high degree of realism this project employs Virtual Reality technology in order to manipulate visual information while pairs of humans interact in a closed loop environment. Further, this technology allows for a precise recording and analysis of the interaction partners behavior such as a flight trajectory of a ball or the body movements of the interaction partners. The investigation of the mechanisms underlying joint action coordination will deepen our knowledge about the influence of social components on our daily lives (e.g. social interactions and learning) and will help to develop systems which are capable to interact with humans in a natural and sophisticated way.

The PhD project is supervised by:

Dr. Stephan De La Rosa

Prof. Dr. Heinrich Buelthoff

Prof. Dr. Guenther Knoblich

Prof. Dr. Natalie Sebanz

The role of visual information in social interactions

Introduction:

Social interactions play a crucial role in our daily life, yet the processes underlying social interactions are not fully understood. Understanding the processes underlying social interactions, however, will finally help to develop, for example, better theories about disorders which impair social interactions (e.g. autism) or to develop artificial systems which can interact with humans more naturally than current systems.

Goals:

The goal is to identify the critical sources of visual information (e.g. biological motion, facial expressions, tool information, and information about interaction objects) for performance and motor control during social interactions. Furthermore we aim to identify the factors which determine the importance of different sources of visual information such as the social context (e.g. competition vs. cooperation). Identifying the critical sources of visual information and the factors which determine the use of visual information will finally help us to understand the psychological processes underlying social interactions.

Methods:

A major goal of this work is to investigate the role of visual information under ecologically valid conditions. In order to provide a high degree of realism in the experiments we apply virtual reality technology (VR). VR provides a highly controlled experimental environment while at the same time remaining the interactive component of a social interaction intact.

Initial results:

We found that the availability of visual information about an interaction partner’s body and visual tool information modulates motor control and performance. We also found that different sources of visual information are weighted differently depending on the social context (cooperative vs. competitive play) (Streuber et al. 2011). This top-down modulation of social context on action and perception needs to be considered in models about action understanding.

Initial conclusion:

Most of our daily actions are performed within a social context and most of our action repertoire has been learned within a social context. Therefore, when investigating human behavior one needs to consider the impact of social context on action and perception. The results of our experiments showed for the first time that the social context influenced the way humans look at the environment and consequently the way how they perform an action.

Video Material:

References:

1. Streuber S, Knoblich G, Sebanz N, Bülthoff HH, and de la Rosa S (2011) The effect of social context on the use of visual information Experimental Brain Research

2. Streuber S, De La Rosa S (2011), The effect of visual information on motor control in social interaction tasks Perception 40 ECVP Abstract Supplement, page 226

3. Dodds TJ, Mohler BJ, de la Rosa S, Streuber S and Bülthoff HH (2011) Embodied interaction in immersive virtual environments with real time self-animated avatars Workshop Embodied Interaction: Theory and Practice in HCI (CHI 2011), ACM Press, New York, NY, USA, 1-4.