Perception and action is linked via the environment. The environment consists of a physical and a social part, and most studies addressing human perception and action have focused on the interaction with the physical world. However, for the proper functioning of an individual, communication and interaction with its social environment is highly important. There is little doubt that perception aids interaction and communication and therefore is essential for an individual in its social context. Furthermore, it is assumed that the human perceptual and action system phylogenetically developed also due to the demands present in social interaction and exchange with others.

Some “special” skills are necessary in social interaction, which are not necessarily required for the interaction with the physical world. Humans need to recognize the actions of others and their goals. They have to perceive inner states like emotions, intentions and beliefs and predict the actions and the course of ongoing movements. Finally, they have to coordinate attention and action when it comes to close interaction. It seems reasonable to assume that the perceptual system has specialized processes dedicated to the processing of social information because of the frequency and abundance with which humans have to deal with social information.

In this area we investigate a) coordination issues between individuals, b) perceptual influences by the mere presence of others, and c) potential specialized perceptual processes in the perception and action during human interaction.

◘ Multi User Interaction and Control
◘ Accessing social information during joint action coordination
◘ The role of perceptual processes in the recognition of social interaction
◘ Motion Perception in Virtual Environments

Multi User Interaction and Control

Collaborative transportation and joint body: Humans posses a notion about the spatial extent of their own body (body scheme) that helps them navigate through the physical environment. Hence, tall people duck when walking through a small door, and narrow passages are crossed sideways. Here we ask how flexible this body scheme is and whether it can be extended to an integrated body scheme (joint body) after prolonged collaboration. For this, pairs actively carry a stretcher through a visually virtual environment. The individuals are thus connected at a fixed distance, and their walking paths are compared to individual behavior.

Attention: Humans and many animals coordinate their behaviour in various tasks in order to achieve a shared goal. While this has been shown in many instances of goal-directed behaviour, it is currently unknown whether coordination takes place also during foraging, scanning, and visual search behaviour of groups. Here, we investigated whether two persons performing together a standard visual search task exhibit a regular spatial preference to which they primarily direct their attention. We vary the nature of the search task with instruction and emphasize either competition, collaboration, or neutrality between the participants while verbal communication is usually prohibited. 

Learning from each other: Manual and motor activity often facilitates recognition and learning. The question here is whether humans have a similar benefit when observing others during their motor activity. We use an object recognition paradigm and compare recognition performance after own examination to observed examination of others.  In addition we are interested in how learning changes in conditions where two individuals are engaged in the task simultaneously.

Dynamic control: The control of a dynamic system is especially challenging for humans. Could the control of a dynamic system be simplified by collaboration? In a dynamic balancing task we investigate the strategies employed during joint control and the extent to which each controller’s behaviour depends on the co-actor’s actions.

Model of joint dynamic control

Funded by the EU Project:
◘ JAST (IST-FP6-003747)

Balance task for studying joint
dynamic control

Stimuli to learn during object
recognition