Perspective Taking and Avatar-Self Merging.

Today, avatars often represent users in digital worlds such as in video games or workplace applications. Avatars embody the user and perform their actions in these artificial environments. As a result, users sometimes develop the feeling that their self merges with their avatar. The user realizes that they are the avatar, but the avatar is also the user-meaning that avatar's appearance, character, and actions also affect their self. In the present paper, we first introduce the event-coding approach of the self and then argue based on the reviewed literature on human-avatar interaction that a self-controlled avatar can lead to avatar-self merging: the user sets their own goals in the virtual environment, plans and executes the avatar's actions, and compares the predicted with the actual motion outcomes of the avatar. This makes the user feel body ownership and agency over the avatar's action. Following the event-coding account, avatar-self merging should not be seen as an all-or-nothing process, but rather as a continuous process to which various factors contribute, including successfully taking the perspective of the avatar. Against this background, we discuss affective, cognitive, and visuo-spatial perspective taking of the avatar. As evidence for avatar-self merging, we present findings showing that when users take the avatar's perspective, they can show spontaneous behavioral tendencies that run counter to their own.

Object affordances from the perspective of an avatar.

Humans often interact with avatars in video gaming, workplace, or health applications, for instance. The present research studied object affordances from an avatar's perspective. In two experiments, participants responded to objects with a left/right keypress, indicating whether the objects were upright or inverted. Task-irrelevant objects' handles were aligned with either the left or right hand of the actor and/or avatar. We hypothesized that actors respond faster when the handles are aligned, as compared to non-aligned, with the respective avatar hand (spatial alignment effect or object-based Simon effect). In Experiment 1, the spatial alignment effect was increased through the presentation of avatar hands as compared to when no hands were presented. In Experiment 2, the avatar perspective was rotated by 90° to the right and left of the actor's view. Here, the spatial alignment effect was guided by the avatar, suggesting that the actors took its perspective when perceiving objects' affordances.

Character Customization With Cosmetic Microtransactions in Games: Subjective Experience and Objective Performance.

Free games that are monetized by selling virtual items, such as cosmetic microtransactions for one's avatar, seem to offer a better gaming experience to paying players. To experimentally explore this phenomenon, the effects of character customization with cosmetic microtransactions on objective and self-estimated player performance, subjective identification with the avatar, fun and the players' perceived competence were examined in the game League of Legends. This study introduces a new laboratory-based, experimental task to objectively measure within-game player performance. Each participant performed this game-based task in two different conditions: With a character that was customized using a provided set of cosmetic microtransactions and with a default character. Results showed that customization increased subjective identification with the player character. However, objective performance measures were unaffected by this manipulation although the novel experimental approach provided reliable performance results. Additionally, identification was positively related to perceived competence, fun, and self-estimated performance. Implications for the design of cosmetic microtransactions and their influence on competitive gaming are discussed.

Human Cognition in Interaction With Robots: Taking the Robot's Perspective Into Account.

OBJECTIVE: The present study investigated whether and how different human-robot interactions in a physically shared workspace influenced human stimulus-response (SR) relationships. BACKGROUND: Human work is increasingly performed in interaction with advanced robots. Since human-robot interaction often takes place in physical proximity, it is crucial to investigate the effects of the robot on human cognition. METHOD: In two experiments, we compared conditions in which humans interacted with a robot that they either remotely controlled or monitored under otherwise comparable conditions in the same shared workspace. The cognitive extent to which the participants took the robot's perspective served as a dependent variable and was evaluated with a SR compatibility task. RESULTS: The results showed pronounced compatibility effects from the robot's perspective when participants had to take the perspective of the robot during the task, but significantly reduced compatibility effects when human and robot did not interact. In both experiments, compatibility effects from the robot's perspective resulted in statistically significant differences in response times and in error rates between compatible and incompatible conditions. CONCLUSION: We concluded that SR relationships from the perspective of the robot need to be considered when designing shared workspaces that require users to take the perspective of the robot. APPLICATION: The results indicate changed compatibility relationships when users share their workplace with an interacting robot and therefore have to take its perspective from time to time. The perspective-dependent processing times are expected to be accompanied by corresponding error rates, which might affect-for instance-safety and efficiency in a production process.

Is effector visibility critical for performance asymmetries in the Simon task? Evidence from hand- and foot-press responses.

The Simon effect is a stimulus-response compatibility effect in which the spatial dimension of the stimulus is task-irrelevant. This effect is often larger in reaction time (RT) for the stimulus located on the dominant-hand side of participants, for most of which it is the right hand, due to dominant-hand keypress responses being faster than non-dominant-hand responses. Experiment 1 demonstrated that pedal-press responses with the left and right feet show a similar asymmetry, favoring the right response for right-footed persons. The asymmetric pattern for keypress responses was absent in results of Wallace (Journal of Experimental Psychology, 93, 163-168, 1972) when participants were not permitted to see the response keys or their hands placed on the keys at any time during the experiment, whereas we found the asymmetric pattern in a recent study when participants placed their hands on the keys prior to their being covered up. Experiments 2 and 3 showed that the Simon effect asymmetry for RT was evident even when participants were prevented from seeing the response device and their responding hands or feet. Although both hands and feet showed a Simon effect asymmetry in RT, consideration of incorrect responses suggested that whereas the asymmetry for hands is not due to a response bias, that for the feet may be due at least in part to such bias. Regardless, our results suggest that the Simon effect asymmetry is mainly an artifact of comparing conditions for which one response is made by the faster dominant right effector and the other with the slower non-dominant left effector.

Seeing the world through the eyes of an avatar? Comparing perspective taking and referential coding.

Previous studies have shown that users spontaneously take the position of a virtual avatar and solve spatial tasks from the avatar's perspective. The common impression is that users develop a spatial representation that allows them to "see" the world through the eyes of the avatar-that is, from its virtual perspective. In the present paper, this perspective taking assumption is compared with a referential coding assumption that allows the user to act on the basis of changed reference points. Using a spatial compatibility task, Experiment 1 demonstrated that visual perspective of the avatar was not the determining factor for taking the avatar's spatial position, but that its hand position (as the reference point) was decisive for the spatial coding of objects. Experiment 2 showed, however, that if the participant's hand position was not corresponding with the avatar's hand positions, the spatial referencing by the avatar's hands expired, thereby demonstrating the limits of referential coding. Still, the present findings indicated that referential coding may be at the base when taking the avatar's perspective. Accordingly, any study in perspective taking needs to consider and evaluate possible mechanisms of referential coding. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Taking time to take perspective? Rapidly changing reference frames in the avatar-Simon task.

The avatar-Simon task demonstrates that even task irrelevant avatars cause compatibility effects from their point of view, a result that can be interpreted within the frameworks of spontaneous spatial perspective taking and referential coding. In the present study, we used an avatar-Simon task with rapidly changing avatar positions and with simultaneous and non-simultaneous presentations to investigate the time course of this phenomenon. The results showed that participants took the avatar's perspective into account even when the avatar's position was randomized on a trial-by-trial basis. This avatar-compatibility effect was also observed when avatar and stimulus were presented simultaneously, even though the participants had no time to adopt the avatar's perspective in advance. However, the effect was much more pronounced when a delay between avatar and stimulus presentation was in place.

Action effect consistency and body ownership in the avatar-Simon task.

Putting oneself in the shoes of a digital alter ego becomes an increasingly relevant part of our everyday experience. In modern day psychology, these interactions can be examined within the frameworks of visual perspective taking and body ownership. Both target similar questions: What does it take, to become one with the avatar? When do we show the same behavior and make the same experiences, as if we were in its place? In this study, we want to address the role of action effect consistency for these concepts. We manipulated the participants' sense of agency over a task-irrelevant avatar in a Simon task by providing either corresponding or random action effects. These effects could be either embodied and therefore linked to the avatar (Experiment 1) or independent of it (Experiment 2). We used stimulus-response compatibility effects from the avatar's point of view as a measure for spontaneous visual perspective taking and a questionnaire to measure the perceived body ownership of the avatar. The results showed that corresponding action effects lead to increased spontaneous perspective taking of the avatar, regardless of whether the effect was linked to the avatar or not. Though the avatar compatibility effects were overall more pronounced in the embodied action effect condition. However, significant differences in perceived body ownership were only observed if the effects were linked to the avatar. The results might prove useful to further our understanding of subjective and objective measurements of interactions with avatars.

Visual perspective taking for avatars in a Simon task.

In modern digital applications, users often interact with virtual representations of themselves or others, called avatars. We examined how these avatars and their perspectives influence stimulus-response compatibility in a Simon task. Participants responded to light/dark blue stimuli with left/right key presses in the presence of a task-irrelevant avatar. Changes in stimulus-response compatibility were used to quantify changes in the mental representation of the task and perspective taking toward this avatar. Experiments 1 and 2 showed that perspective taking for an avatar occurred in orthogonal stimulus-response mappings, causing a compatibility effect from the avatar's point of view. In the following two experiments we introduced a larger variety of angular disparities between the participant and avatar. In Experiment 3, the Simon effect with lateralized stimulus positions remained largely unaffected by the avatar, pointing toward an absence of perspective taking. In Experiment 4, after avatar hand movements were added in order to strengthen the participants' sense of agency over the avatar, a spatial compatibility effect from the avatar's perspective was observed again, and hints of the selective use of perspective taking on a trial-by-trial basis were found. Overall, the results indicate that users can incorporate the perspective of an avatar into their mental representation of a situation, even when this perspective is unnecessary to complete a task, but that certain contextual requirements have to be met.

Reversed effect of spatial compatibility when taking avatar's perspective.

If an actor takes the perspective of an avatar, spatial dissociations could arise between the perspective of the actor and the perspective of the avatar. These become particularly interesting when solving spatial compatibility tasks. Effects of spatial compatibility are usually explained by a match or mismatch of automatic behavioural tendencies and intentional mapping processes. The question is whether actors develop such behavioural tendencies for an avatar and thereby are able to neglect their own perspective. In the experiments, actors take the perspective of the avatar and pressed ipsilateral or contralateral left-right keys in response to lateralised coloured discs. Experiments 1 and 2 showed that compatibility effects are tied to the avatar but not to the actor. Experiment 3 revealed that participants could ignore the perspective of the avatar. We concluded that the automatic behavioural tendencies in compatibility experiments are not as automatic as sometimes assumed. It is likely that the present results are not only applicable to the use of avatars but also to other human-controlled robots and drones.

Perceived Ownership of Avatars Influences Visual Perspective Taking.

Modern computer-based applications often require the user to interact with avatars. Depending on the task at hand, spatial dissociation between the orientations of the user and the avatars might arise. As a consequence, the user has to adopt the avatar's perspective and identify herself/himself with the avatar, possibly changing the user's self-representation in the process. The present study aims to identify the conditions that benefit this change of perspective with objective performance measures and subjective self-estimations by integrating the idea of avatar-ownership into the cognitive phenomenon of spatial compatibility. Two different instructions were used to manipulate a user's perceived ownership of an avatar in otherwise identical situations. Users with the high-ownership instruction reported higher levels of perceived ownership of the avatar and showed larger spatial compatibility effects from the avatar's point of view in comparison to the low ownership instruction. This supports the hypothesis that perceived ownership benefits perspective taking.

Constrained postures and spatial S-R compatibility as measured by the Simon effect.

Whereas working under constrained postures is known to influence the worker's perceived comfort and health, little is known in regard to its influence on performance. Employing an Auditory Simon task while varying posture, we investigated the relationship between constrained postures and cognitive processes in three experiments. In Experiment 1 and 2, participants operated a rocker switch or a control knob with one hand either in front or in the back of their body and while either sitting or kneeling. Perceived musculoskeletal exertion was gathered with a questionnaire. Results of the first two experiments showed differently perceived comfort and a minor effect of constrained posture on cognitive performance. However, results indicated that spatial coding in the back compares to either a virtual turn of the observer towards the control device (front-device coding) or along the observer's hand (effector coding). To clarify this issue the rocker switch was operated with one or two hands in Experiment 3, showing a comparable coding only in the one-hand condition and indicating evidence for the effector-coding hypothesis in the back.

Using tools with real and imagined tool movements.

WHEN USING LEVER TOOLS, SUBJECTS HAVE TO DEAL WITH TWO, NOT NECESSARILY CONCORDANT EFFECTS OF THEIR MOTOR BEHAVIOR: the body-related proximal effects, like tactile sensations from the moving hand, and/or more external distal effects, like the moving effect points of the lever. As a consequence, spatial compatibility relationships between stimulus (S; at which the effect points of the lever aim at), responding hand (R) and effect point of the lever (E) play a critical role in response generation. In the present study we examine whether the occurrence of compatibility effects needs real tool movements or whether a similar response pattern can be already evoked by pure mental imaginations of the tool effects. In general, response times and errors observed with real and imagined tool movements showed a similar pattern of results, but there were also differences. With incompatible relationships and thus more difficult tasks, response times were reduced with imagined tool movements than compared with real tool movements. On the contrary, with compatible relationships and thus high overlap between proximal and distal action effects, response times were increased with imagined tool movements. Results are only in parts consistent with the ideomotor theory of motor control.

Concurrent adaptation to opposite visual distortions: impairment and cue.

The present study compared single and dual adaptation to visuomotor rotations in different cueing conditions. Participants adapted either to a constant rotation or to opposing rotations (dual adaptation) applied in an alternating order. In Experiment 1, visual and corresponding postural cues were provided to indicate different rotation directions. In Experiment 2, either a visual or a postural cue was available. In all cueing conditions, substantial dual adaptation was observed, although it was attenuated in comparison to single adaptation. Analysis of switching costs determined as the performance difference between the last trial before and the first trial after the change of rotation direction suggested substantial advantage of the visual cue compared to the postural cue, which was in line with previous findings demonstrating the dominance of visual sense in movement representation and control.

Intra- and intermodal integration of discrepant visual and proprioceptive action effects.

Integration of discrepant visual and proprioceptive action effects puts high demands on the human information processing system. The present study aimed to examine the integration mechanisms for the motor (Exp. 1) and visual modality (Exp. 2). According to theories of common coding, we assumed that visual as well as proprioceptive information is represented within the same cognitive domain and is therefore likely to affect each other (multisensory cross talk). Thus, apart from the often-confirmed visual dominance in multisensory integration, we asked about intra- and intermodal recall of either proprioceptive or visual information and whether there were any differences between the motor and visual modality. In a replication paradigm, we perturbed the relation between hand movements and cursor movements. The task required the (intra- vs. intermodal) replication of an initially performed (seen) hand (cursor) movement in a subsequent motor (visual) replication phase. First, mechanisms of integration were found to be dependent on the output modality. Visual action effects interfered the motor modality, but proprioceptive action effects did not have any effects on the visual modality. Second, however, intermodal integration was more susceptible to interference, and this was found to be independent from the output modality. Third, for the motor modality, the locus of perturbation (perturbation of cursor amplitude or perturbation of hand amplitude) was irrelevant, but for the visual modality, perturbation of hand amplitudes reduced the cross talk. Tool use is one field of application of these kinds of results, since the optimized integration of conflicting action effects is a precondition for using tools successfully.

Spatial realignment in sensorimotor adaptation: taking the efficiency into account.

The present study reviewed the modular approach in adaptive motor control by taking cognitive efficiency into account. Three experiments were conducted to compare different visuomotor learning mechanisms (modular adaptation, use-dependent plasticity, and spatial realignment) in response to visuomotor rotations. During exposure, the visual feedback of flicking movements in a single-target scenario was rotated either 30° clockwise (CW) or counterclockwise (CCW) at the left and right starting locations, respectively. Exposure to the CW and CCW rotations was carried out in an alternating order. After adaptation to the rotations, generalization was evaluated by assessing aftereffects from a set of untrained starting locations to the target (Experiments 1 and 2) or from the trained starting locations to a set of new targets (Experiment 3). Predictions made based on the different visuomotor learning mechanisms were compared to the empirical data. In spite of evidential advantages of modular structure, the current work could show a particular case of visuomotor transformation, in which modularity lacks efficiency. Results indicate that the adaptive motor control system employed the spatial realignment to accomplish adaptation more efficiently.

Vision and proprioception in action monitoring by young and older adults.

Discrimination of proprioceptive and visual spatial information is a prerequisite for the learning of visuo-motor transformations. This study investigated the individual's capability to discriminate the directions of seen cursor motions and felt hand movements under a visuo-motor rotation paradigm and its age-related variation. Young and older participants performed 3-stroke arm movements on a digitizing tablet without seeing their arm. The visual feedback of the second stroke was rotated randomly by various angles ranging from -30° to 30° and displayed on a monitor. Older adults were poorer in discrimination than young adults. In both age groups, the felt hand direction was shifted toward the seen cursor direction (i.e., visual capture) by approximately 25% to 30% of the rotation of the visual feedback. Older adults also showed an enhanced visual capture. The results suggest that both the increased sensory noise and the increased assimilation of the bimodal information cause the reduction of discrimination capability in older adults. These findings provide underlying reasons for age-related changes in learning a new visuo-motor transformation.

Regional accent variation in the shadowing task: evidence for a loose perception-action coupling in speech.

We investigated the relation between action and perception in speech processing, using the shadowing task, in which participants repeat words they hear. In support of a tight perception-action link, previous work has shown that phonetic details in the stimulus influence the shadowing response. On the other hand, latencies do not seem to suffer if stimulus and response differ in their articulatory properties. The present investigation tested how perception influences production when participants are confronted with regional variation. Results showed that participants often imitate a regional variation if it occurs in the stimulus set but tend to stick to their variant if the stimuli are consistent. Participants were forced or induced to correct by the experimental instructions. Articulatory stimulus-response differences do not lead to latency costs. These data indicate that speech perception does not necessarily recruit the production system.

The perceived onset position of a moving target: effects of trial contexts are evoked by different attentional allocations.

Previous studies have shown that the localization of the perceived onset position of a moving target varies with the trial context. When the moving target appeared at predictable positions to the left or right of fixation (constant context), localization judgments of the perceived onset positions were essentially displaced in motion direction (Fröhlich effect). In contrast, when the target appeared at unpredictable positions in the visual field (random context), localization judgments were at least drastically reduced. Four explanations of this influence of trial context on localization judgments were examined in three experiments. Findings ruled out an overcompensation mechanism effective in random-context conditions, a predictive mechanism effective in constant-context conditions and a detrimental mechanism originating from more trial repetitions in constant-context conditions. Instead, the results indicated that different attentional allocations are responsible for the localization differences. They also demonstrated that attentional mechanisms are at the basis of the Fröhlich effect.