Stephan de la Rosa

• Ph.D.
• Professor at Fachhoschule für Oekonomie und Management

The goal of new adaptive technologies is to allow humans to interact with technical devices, such as robots, in natural ways akin to human interaction. Essential for achieving this goal, is the understanding of the factors that support natural interaction. Here, we examined whether human motor control is linked to the visual appearance of the inter...

The creation or streaming of photo-realistic self-avatars is important for virtual reality applications that aim for perception and action to replicate real world experience. The appearance and recognition of a digital self-avatar may be especially important for applications related to telepresence, embodied virtual reality, or immersive games. We...

Significance Why is it so easy for humans to interact with each other? In social interactions, humans coordinate their actions with each other nonverbally. For example, dance partners need to relate their actions to each other to coordinate their movements. The underlying neurocognitive mechanisms supporting this ability are surprisingly poorly und...

Motor-based theories of facial expression recognition propose that the visual perception of facial expression is aided by sensorimotor processes that are also used for the production of the same expression. Accordingly, sensorimotor and visual processes should provide congruent emotional information about a facial expression. Here, we report eviden...

One major challenge of social interaction research is to achieve high experimental control over social interactions to allow for rigorous scientific reasoning. Virtual reality (VR) promises this level of control. Pan and Hamilton guide us with a detailed review on existing and future possibilities and challenges of using VR for social interaction r...

So far, action recognition has been mainly examined with small point-light human stimuli presented alone within a narrow central area of the observer’s visual field. Yet, we need to recognize the actions of life-size humans viewed alone or surrounded by bystanders, whether they are seen in central or peripheral vision. Here, we examined the mechani...

Recognizing who is carrying out an action is essential for successful human interaction. The cognitive mechanisms underlying this ability are little understood and have been subject of discussions in embodied approaches to action recognition. Here we examine one solution, that visual action recognition processes are at least partly sensitive to the...

The previous body image literature has focused on how females perceive their body weight. We investigated potential gender differences in the use of visual cues (shape, texture) to estimate own body weight. A full-body scanner was used to capture each participant’s own body geometry and colour information and a set of nine personalized 3D virtual b...

Cultural differences in spatial perception have been little investigated, which gives rise to the impression that spatial cognitive processes might be universal. Contrary to this idea, we demonstrate cultural differences in spatial volume perception of computer generated rooms between Germans and South Koreans. We used a psychophysical task in whic...

Recognizing actions of others across the whole visual field is required for social interactions. In a previous study, we have shown that recognition is very good even when life size avatars who were facing the observer carried out actions (e.g. waving) were presented very far away from the fovea (Fademrecht, Bülthoff, & de la Rosa, 2016). We explor...

Data and analysis script. (ZIP)

Recent studies have shown the presence of distortions in proprioceptive hand localization tasks. Those results were interpreted as reflecting specific perceptual distortions bound to a body model. It was especially suggested that hand distortions could be related to distortions of somatotopic cortical maps. In this study, we show that hand distorti...

In real life humans need to recognize actions even if the actor is surrounded by a crowd of people but little is known about action recognition in cluttered environments. In the current study, we investigated whether a crowd influences action recognition with an adaptation paradigm. Using life-sized moving stimuli presented on a panoramic display,...

It has been suggested that the motor system is essential for various social cognitive functions including the perception of actions in social interactions. Typically, the influence of the motor system on action recognition has been addressed in studies in which participants are merely action observers. This is in stark contrast to real social inter...

A long standing debate revolves around the question whether visual action recognition primarily relies on visual or motor action information. Previous studies mainly examined the contribution of either visual or motor information to action recognition. Yet, the interaction of visual and motor action information is particularly important for underst...

People maintain larger distances to other peoples’ front than to their back. We investigated if humans also judge another person as closer when viewing their front than their back. Participants watched animated virtual characters (avatars) and moved a virtual plane toward their location after the avatar was removed. In Experiment 1, participants ju...

Mirror neurons (MNs) are considered to be the supporting neural mechanism for action understanding. MNs have been identified in monkey’s area F5. The identification of MNs in the human homolog of monkeys’ area F5 Broadmann Area 44/45 (BA 44/45) has been proven methodologically difficult. Cross-modal functional MRI (fMRI) adaptation studies supporti...

Recognizing whether the gestures of somebody mean a greeting or a threat is crucial for social interactions. In real life, action recognition occurs over the entire visual field. In contrast, much of the previous research on action recognition has primarily focused on central vision. Here our goal is to examine what can be perceived about an action...

The ability to discriminate between different actions is essential for action recognition and social interactions. Surprisingly previous research has often probed action recognition mechanisms with tasks that did not require participants to discriminate between actions, e.g., left-right direction discrimination tasks. It is not known to what degree...

Several studies have shown that the perception of one's own hand size is distorted in proprioceptive localization tasks. It has been suggested that those distortions mirror somatosensory anisotropies. Recent research suggests that non-corporeal items also show some spatial distortions. In order to investigate the psychological processes underlying...

Perceiving social information such as the cooperativeness of another person is an important part of human interaction. But can people perceive the cooperativeness of others even without any visual or auditory information? In a novel experimental setup, we connected two people with a rope and made them accomplish a point-collecting task together whi...

Although actions often appear in the visual periphery, little is known about action recognition outside of the fovea. Our previous results have shown that action recognition of moving life-size human stick figures is surprisingly accurate even in far periphery and declines non-linearly with eccentricity. Here, our aim was (1) to investigate the inf...

The way we use social actions in everyday life to interact with other people differs across various cultures. Can this cultural specificity of social interactions be already observed in perceptual processes underlying the visual recognition of actions? In the current study, we investigated whether there were any differences in action recognition be...

How do we control our bodily movements when socially interacting with others? Research on online motor control provides evidence that task relevant visual information is used for guiding corrective movements of ongoing motor actions. In social interactions observers have been shown to use their own motor system for predicting the outcome of another...

Accurate knowledge about size and shape of the body derived from somatosensation is important to locate one’s own body in space. The internal representation of these body metrics (body model) has been assessed by contrasting the distortions of participants’ body estimates across two types of tasks (localization task vs. template matching task). Her...

Prominent theories of action recognition suggest that during the recognition of actions the physical patterns of the action is associated with only one action interpretation (e.g., a person waving his arm is recognized as waving). In contrast to this view, studies examining the visual categorization of objects show that objects are recognized in mu...

Emotion expression in human-human interaction takes place via various types of information, including body motion. Research on the perceptual-cognitive mechanisms underlying the processing of natural emotional body language can benefit greatly from datasets of natural emotional body expressions that facilitate stimulus manipulation and analysis. Th...

Thresholds for detecting a gap between two complex tones were determined for young listeners with normal hearing and old listeners with mild age-related hearing loss. The leading tonal marker was always a 20-ms, 250-Hz complex tone with energy at 250, 500, 750, and 1000 Hz. The lagging marker, also tonal, could differ from the leading marker with r...

The goal of this research was to investigate women's sensitivity to changes in their perceived weight by altering the body mass index (BMI) of the participants' personalized avatars displayed on a large-screen immersive display. We created the personalized avatars with a full-body 3D scanner that records the participants' body geometry and texture....

The visual recognition of actions occurs at different levels. At a kinematic level, an action can be described as the physical movement of a body part in space and time, whereas at a semantic level, an action can carry various social meanings such as the goals or intentions of an action. A substantial amount of neuroscientific research work has bee...

The perception and interpretation of social cues is important in order to coordinate one’s actions and movements with another individual. Especially human actions, consisting of motion cues, seem to provide an extensive array of socially relevant information and play a central role by providing reliable interpretations of complex visual information...

Action recognition research has mainly focused on investigating the perceptual processes in the recognition of isolated actions from biological motion patterns. Surprisingly little is known about the cognitive representation underlying action recognition. A fundamental question concerns whether actions are represented independently or interdependen...

Actions do not occur out of the blue. Rather, they are often a part of human interactions and are, therefore, embedded in an action sequence. Previous research on visual action recognition has primarily focused on elucidating the perceptual and cognitive mechanisms in the recognition of individual actions. Surprisingly, the social and temporal cont...

Stored representations of body size and shape as derived from somatosensation (body model) are considered to be critical components of perception and action. It is commonly believed that the body model can be measured using a localization task and be distinguished from other visual representations of the body using a visual template matching task....

Visual action recognition is a prerequisite for humans to physically interact with other humans. Do we use similar perceptual mechanisms when recognizing actions from a photo (static) or a movie (dynamic)? We used an adaptation paradigm to explore whether static and dynamic action information is processed in separate or interdependent action-sensit...

How do we recognize different actions? Action recognition has been a captivating topic for a long time, and previous studies have shown that specific representations of human actions might be encoded in brain regions such as the STS or the IFG. However, many studies have rather focused on the spatio-temporal dynamics of actions using single action...

Cook et al. suggest that motor-visual neurons originate from associative learning. This suggestion has interesting implications for the processing of socially relevant visual information in social interactions. Here, we discuss two aspects of the associative learning account that seem to have particular relevance for visual recognition of social in...

The social context in which an action is embedded provides important information for the interpretation of an action. Is this social context integrated during the visual recognition of an action? We used a behavioural visual adaptation paradigm to address this question and measured participants' perceptual bias of a test action after they were adap...

Previous research suggests that bodily self-identification, bodily self-localization, agency, and the sense of being present in space are critical aspects of conscious full-body self-perception. However, none of the existing studies have investigated the relationship of these aspects to each other, i.e., whether they can be identified to be disting...

Recognizing social interactions, e.g., two people shaking hands, is important for obtaining information about other people and the surrounding social environment. Despite the visual complexity of social interactions, humans have often little difficulties to visually recognize social interactions. What is the visual representation of social interact...

We wanted to investigate whether judgments of personality traits based on brief visual observations, namely the ‘thin slicing’ approach, can also be replicated with biological motion cues consisting of point-light stimuli when different sorts of natural human actions were carried out. We captured six different actions carried out by ten different p...

Action recognition is critical for successful human interaction. Previous research highlighted the importance of the motor system to visual action recognition. Little is known about the visual tuning properties of processes involved in action recognition. Here we examined the visual tuning properties of processes involved in action recognition by m...

Many scientists have demonstrated that compared to the real world egocentric distances in head-mounted display virtual environments are underestimated. However, distance perception in large screen immersive displays has received less attention. We investigate egocentric distance perception in a virtual office room projected using a semi-spherical,...

Probing emotional facial expression recognition with the adaptation paradigm is one way to investigate the processes underlying emotional face recognition. Previous research suggests that these processes are tuned to dynamic facial information (facial movement). Here we examined the tuning of processes involved in the recognition of emotional facia...

Theories of social interaction (i.e., common coding theory) suggest that visual information about the interaction partner is critical for successful interpersonal action coordination. Seeing the interaction partner allows an observer to understand and predict the interaction partner's behavior. However, it is unknown which of the many sources of vi...

Humans have been shown to perceive and perform actions differently in immersive virtual environments (VEs) as compared to the real world. Immersive VEs often lack the presence of virtual characters; users are rarely presented with a representation of their own body and have little to no experience with other human avatars/characters. However, virtu...

Social context modulates action kinematics. Less is known about whether social context also affects the use of task relevant visual information. We tested this hypothesis by examining whether the instruction to play table tennis competitively or cooperatively affected the kind of visual cues necessary for successful table tennis performance. In two...

Recent evidence suggests that the recognition of an object's presence and its explicit recognition are temporally closely related. Here we re-examined the time course (using a fine and a coarse temporal resolution) and the sensitivity of three possible component processes of visual object recognition. In particular, participants saw briefly present...

People underestimate egocentric distances in head-mounted display virtual environments, as compared to estimates done in the real world. Our work investigates whether distances are still compressed in a large screen display immersive virtual environment, where participants are able to see their own body surrounded by the virtual environment. We con...

Research has shown that the visual system's sensitivity to variations in luminance (visual contrast) within a particular area of the retina is affected in a bottom-up fashion by the ambient contrast levels in nearby regions. Specifically, changes in the ambient contrast in areas surrounding the target area alter the sensitivity to visual contrast w...

A plausible assumption is that self-avatars increase the realism of immersive virtual environments (VEs), because self-avatars provide the user with a visual representation of his/her own body. Consequently having a self-avatar might lead to more realistic human behavior in VEs. To test this hypothesis we compared human behavior in VE with and with...

Nakayama and Silverman (1986) proposed that, when searching for a target defined by a conjunction of color and stereoscopic depth, observers partition 3D space into separate depth planes and then rapidly search each such plane in turn, thereby turning a conjunctive search into a "feature" search. In their study, they found, consistent with their hy...