Ulrich J. Pfeiffer

Bio: Ulrich J. Pfeiffer is an academic researcher from University of Cologne. The author has contributed to research in topics: Gaze & Social relation. The author has an hindex of 10, co-authored 12 publications receiving 610 citations. Previous affiliations of Ulrich J. Pfeiffer include Forschungszentrum Jülich.

It’s in your eyes—using gaze-contingent stimuli to create truly interactive paradigms for social cognitive and affective neuroscience

Abstract: The field of social neuroscience has made remarkable progress in elucidating the neural mechanisms of social cognition. More recently, the need for new experimental approaches has been highlighted that allow studying social encounters in a truly interactive manner by establishing 'online' reciprocity in social interaction. In this article, we present a newly developed adaptation of a method which uses eyetracking data obtained from participants in real time to control visual stimulation during functional magnetic resonance imaging, thus, providing an innovative tool to generate gaze-contingent stimuli in spite of the constraints of this experimental setting. We review results of two paradigms employing this technique and demonstrate how gaze data can be used to animate a virtual character whose behavior becomes 'responsive' to being looked at allowing the participant to engage in 'online' interaction with this virtual other in real-time. Possible applications of this setup are discussed highlighting the potential of this development as a new 'tool of the trade' in social cognitive and affective neuroscience.

A Non-Verbal Turing Test: Differentiating Mind from Machine in Gaze-Based Social Interaction

Abstract: In social interaction, gaze behavior provides important signals that have a significant impact on our perception of others. Previous investigations, however, have relied on paradigms in which participants are passive observers of other persons’ gazes and do not adjust their gaze behavior as is the case in real-life social encounters. We used an interactive eye-tracking paradigm that allows participants to interact with an anthropomorphic virtual character whose gaze behavior is responsive to where the participant looks on the stimulus screen in real time. The character’s gaze reactions were systematically varied along a continuum from a maximal probability of gaze aversion to a maximal probability of gaze-following during brief interactions, thereby varying contingency and congruency of the reactions. We investigated how these variations influenced whether participants believed that the character was controlled by another person (i.e., a confederate) or a computer program. In a series of experiments, the human confederate was either introduced as naive to the task, cooperative, or competitive. Results demonstrate that the ascription of humanness increases with higher congruency of gaze reactions when participants are interacting with a naive partner. In contrast, humanness ascription is driven by the degree of contingency irrespective of congruency when the confederate was introduced as cooperative. Conversely, during interaction with a competitive confederate, judgments were neither based on congruency nor on contingency. These results offer important insights into what renders the experience of an interaction truly social: Humans appear to have a default expectation of reciprocation that can be influenced drastically by the presumed disposition of the interactor to either cooperate or compete.

Towards a neuroscience of social interaction.

Abstract: The burgeoning field of social neuroscience has begun to illuminate the complex biological bases of human social cognitive abilities. However, in spite of being based on the premise of investigating the neural bases of interacting individuals, a majority of studies has focused on studying brains in isolation using paradigms that investigate “offline” social cognition, i.e., social cognition from an observer's point of view, rather than “online” social cognition, i.e., social cognition from an interactor's point of view. Consequently, the neural correlates of real-time social interaction have remained largely elusive and may—paradoxically—be seen to represent the “dark matter” of social neuroscience (Schilbach et al., 2013). More recently, a growing number of researchers have begun to study social cognition from an interactor's point of view, based on the assumption that there is something fundamentally different when we are actively engaged with others in real-time social interaction as compared to when we merely observe them. Whereas for “offline” social cognition, interaction and feedback are merely a way of gathering data about the other person that feeds into processing algorithms “inside” the agent, it has been proposed that in “online” social interaction the knowledge of the other—at least in part—may reside in the interaction dynamics “between” the agents. Furthermore, being a participant in an interaction may entail a commitment toward being responsive created by important difference in the motivational foundations of “online” and “offline” social cognition. There are at least three different axes along which social neuroscience will have to evolve in order to (a) be able to validate the idea that interaction is more than just an online recruitment of essentially two or more agents' internal social knowledge, and (b) move toward a true understanding of what it is like to exist and function in a social context. In a recent paper (Schilbach et al., 2013; see Figure ​Figure1),1), we describe one axis representing detachment versus emotional engagement; a second axis that runs from purely spectatorial setups to setups that allow participants to produce a meaningful change in their environment, to paradigms in which two agents can interact with each other in a dynamic way; and a third axis that contrasts methodologies that look for explanatory variance within a single agent with approaches focusing on explanatory power of a system of multiple agents. It is important to note that a more enactive approach that incorporates meaningful interaction need not necessarily focus exclusively on dynamic components of ongoing interaction. For instance, establishing the degree to which “passive” social perception and related biobehavioral markers change when in interaction as compared to merely observing, or the study of how we perceive cooperative interaction and adapt to it, is extremely useful and necessary in order to come to a full understanding of social interaction. Figure 1 Depiction of the experimental landscape of research in social neuroscience. More intense shades of gray indicate areas of the landscape, which have been left largely unexplored, thus, representing the “dark matter” of social neuroscience. ... In this line of thought, this Frontiers Research Topic brings together contributions from researchers in social neuroscience and related fields, whose work contributes to the development of the neuroscientific investigation of “online” social cognition and draws upon behavioral studies, psychophysiological investigations, computational approaches, developmental, and patient studies while also providing theoretical contributions that can help to advance research in social neuroscience. This creates an interdisciplinary perspective on what it is that separates “online” from “offline” social cognition and how differences in the underlying neurobiological processes and mechanisms can be investigated. The contributions highlight the importance of methodological advances to quantify the interpersonal processes of real-time social interaction and demonstrate how this can be related to measurements obtained from one or two brains. Without going into each of the 52 contributions to this Research Topic, there are a number of emerging patterns coming to the foreground. All of them, to some degree, focus on at least one aspect of the three axes and try to find an explanation of behavioral variance that cannot be found by exclusively focusing on disengaged agents—be it in engagement, active participation in joint actions, or in the interaction dynamics itself. The theoretical contributions shed light on how recent findings might reveal the crucial and subtle differences between spectatorial versus interactionist social cognition. Moreover, they suggest various ways of conceptualizing this distinction by focusing on coordination dynamics or interactive alignment/synchronization, cooperation, intentionality, brain-computer interfaces, differential involvement of (conscious) top-down processes, and more implicit, automatic processing, or by pointing toward findings in developmental neuroscience. Among the original research articles, a number focus on neural correlates of some form of live social interaction, either face-to-face, or via gaze and joint attention, joint action in various dual tasks such as imitation, behavioral or listener-speaker coupling. These are not limited to investigating only single agents' neural correlates, but also look at the coupling of participants' neural correlates within an interactive setup. The field of interest pertaining to the nature of interaction stretches far beyond that and incorporates inquiries into risk-taking, inequity, deception—often in the context of games, emotion, and face perception, machine interaction, the role of oxytocin, and specific interaction deficits in persons with autism. By focusing on cutting-edge research in social neuroscience and related areas, this Frontiers Research Topic allows new insights into the neurobiology of social interaction and demonstrates how the field of social neuroscience is now tackling issues that were at the very heart of the field until its inception, but have proved to be more difficult to assess. Beyond the excellent contributions that make up this Research Topic, we believe that this special focus will also give readers ideas for future research in this field, which—we hope—will continue to turn toward the investigation of phenomena that are inherently linked to participation in social interaction and may therein help social neuroscience to really go social.

Toward a second-person neuroscience.

Abstract: In spite of the remarkable progress made in the burgeoning field of social neuroscience, the neural mechanisms that underlie social encounters are only beginning to be studied and could-paradoxically-be seen as representing the "dark matter" of social neuroscience. Recent conceptual and empirical developments consistently indicate the need for investigations that allow the study of real-time social encounters in a truly interactive manner. This suggestion is based on the premise that social cognition is fundamentally different when we are in interaction with others rather than merely observing them. In this article, we outline the theoretical conception of a second-person approach to other minds and review evidence from neuroimaging, psychophysiological studies, and related fields to argue for the development of a second-person neuroscience, which will help neuroscience to really "go social"; this may also be relevant for our understanding of psychiatric disorders construed as disorders of social cognition.

Virtual Reality for Enhanced Ecological Validity and Experimental Control in the Clinical, Affective and Social Neurosciences.

Abstract: An essential tension can be found between researchers interested in ecological validity and those concerned with maintaining experimental control. Research in the human neurosciences often involves the use of simple and static stimuli lacking many of the potentially important aspects of real world activities and interactions. While this research is valuable, there is a growing interest in the human neurosciences to use cues about target states in the real world via multimodal scenarios that involve visual, semantic, and prosodic information. These scenarios should include dynamic stimuli presented concurrently or serially in a manner that allows researchers to assess the integrative processes carried out by perceivers over time. Furthermore, there is growing interest in contextually embedded stimuli that can constrain participant interpretations of cues about a target’s internal states. Virtual reality environments proffer assessment paradigms that combine the experimental control of laboratory measures with emotionally engaging background narratives to enhance affective experience and social interactions. The present review highlights the potential of virtual reality environments for enhanced ecological validity in the clinical, affective, and social neurosciences.