Although research in our department has a clear focus on interpersonal perception and interactions between humans, technological progress has already changed the reality of social interactions for many people. Accordingly, the importance of interactions between humans and machines (e.g., in the form of smartphones, computers, or robots) not only is increasing quickly – there are also many potential applications to psychology which come with both chances and challenges. For instance, the extent to which service robots can make a positive contribution to care services for the elderly – already a partial reality in countries such as Japan – is discussed controversially. Another example are virtual reality applications, which are beginning to play a role in clinical interventions, such as in cases of specific affective disorders. Such applications can also be used for training purposes to enhance cognitive and social abilities, and may be complemented by techniques of bio- or neurofeedback that are currently becoming validated as effective treatments for disorders such as ADHD or autism. Moreover, there is currently intense research to understand the conditions for the so-called sense of agency (the subjective impression that one´s own action has been the cause of an external response), which may be a crucial factor for smooth and pleasant interactions between humans and machines. In one project, we investigate the role of several variables (latency, (multi-)sensory nature, and affective valence of machine-generated responses to human actions) for the sense of agency. In a second related project, we specifically target human-robot interactions, and investigate the degree to which both human (e.g., age, personality, anxiety levels) and robot (e.g., degree of humanoid appearance, size, motion parameters) variables can reduce anxiety and promote smooth interactions between humans and robots.