The influence of another's actions and presence on perspective taking.

The ability to take each other's visuospatial perspective has been linked to people's capacity to perceive another's action possibilities and to predict their actions. Research has also shown that visuospatial perspective taking is supported by one's own mental own-body transformation. However, how these two processes of action perception and visuospatial perspective taking might interact remains largely unknown. By introducing seven angular disparities between participants and the model in the stimuli pictures across "Action" and "No Action" conditions, we investigated whether the observation of a goal-directed action facilitates perspective taking and whether this facilitation depends on the level of mental own-body transformation required to take perspective. The results showed that action observation facilitated performance independently of the level of mental-own body transformation. The processes behind this facilitation could involve anatomical mapping that is independent of the congruency between the participants' and the model's perspectives. Further, we replicated previous research findings, showing that participants were more accurate and faster when taking the perspective of a person compared to an inanimate object (a chair). The strongest facilitation effects were seen at the highest angular disparities between participants and the model in the stimuli pictures. Together, these findings enhance our knowledge of the mechanisms behind visuospatial perspective taking.

Can 18-Month-Olds Revise Attributed Beliefs?

Successful social interactions rely on flexibly tracking and revising others' beliefs. These can be revised prospectively, new events leading to new beliefs, or retrospectively, when realizing that an attribution may have been incorrect. However, whether infants are capable of such belief revisions is an open question. We tested whether 18-month-olds can revise an attributed FB into a TB when they learn that a person may have witnessed an event that they initially thought she could not see. Infants first observed Experimenter 1 (E1) hiding two objects into two boxes. Then E1 left the room, and the locations of the objects were swapped. Infants then accompanied Experimenter 2 (E2) to the adjacent room. In the FB-revised-to-TB condition, infants observed E1 peeking into the experimental room through a one-way mirror, whereas in the FB-stays-FB condition, they observed E1 reading a book. After returning to the experimental room E1 requested an object by pointing to one of the boxes. In the FB-stays-FB condition, most infants chose the non-referred box, congruently with the agent's FB. However, in the FB-revised-to-TB condition, most infants chose the other, referred box. Thus, 18-month-olds revised an already attributed FB after receiving evidence that this attribution might have been wrong.

How 15-month-old infants process morphologically complex forms in an agglutinative language?

While phonological development is well-studied in infants, we know less about morphological development. Previous studies suggest that infants around one year of age can process words analytically (i.e., they can decompose complex forms to a word stem and its affixes) in morphologically simpler languages such as English and French. The current study explored whether 15-month-old infants learning Hungarian, a morphologically complex, agglutinative language with vowel harmony, are able to decompose words into a word stem and a suffix. Potential differences between analytical processing of complex forms with back versus front vowels were also studied. The results of Experiment 1 indicate that Hungarian infants process morphologically complex words analytically when they contain a frequent suffix. Analytic processing is present both in the case of complex forms with back and front vowels according to the results of Experiment 2. In light of the results, we argue for the potential relevance of the early development of analytic processing for language development.

Reading Your Mind While You Are Reading-Evidence for Spontaneous Visuospatial Perspective Taking During a Semantic Categorization Task.

Recent studies have demonstrated people's propensity to adopt others' visuospatial perspectives (VSPs) in a shared physical context. The present study investigated whether spontaneous VSP taking occurs in mental space where another person's perspective matters for mental activities rather than physical actions. Participants sat at a 90° angle to a confederate and performed a semantic categorization task on written words. From the participants' point of view, words were always displayed vertically, while for the confederate, these words appeared either the right way up or upside down, depending on the confederate's sitting position. Participants took longer to categorize words that were upside down for the confederate, suggesting that they adopted the confederate's VSP without being prompted to do so. Importantly, the effect disappeared if the other's visual access was impeded by opaque goggles. This demonstrates that human adults show a spontaneous sensitivity to others' VSP in the context of mental activities, such as joint reading.

Seeing behind the surface: communicative demonstration boosts category disambiguation in 12-month-olds.

In their first years, infants acquire an incredible amount of information regarding the objects present in their environment. While often it is not clear what specific information should be prioritized in encoding from the many characteristics of an object, different types of object representations facilitate different types of generalizations. We tested the hypotheses that 1-year-old infants distinctively represent familiar objects as exemplars of their kind, and that ostensive communication plays a role in determining kind membership for ambiguous objects. In the training phase of our experiment, infants were exposed to movies displaying an agent sorting objects from two categories (cups and plates) into two locations (left or right). Afterwards, different groups of infants saw either an ostensive or a non-ostensive demonstration performed by the agent, revealing that a new object that looked like a plate can be transformed into a cup. A third group of infants experienced no demonstration regarding the new object. During test, infants were presented with the ambiguous object in the plate format, and we measured generalization by coding anticipatory looks to the plate or the cup side. While infants looked equally often towards the two sides when the demonstration was non-ostensive, and more often to the plate side when there was no demonstration, they performed more anticipatory eye movements to the cup side when the demonstration was ostensive. Thus, ostensive demonstration likely highlighted the hidden dispositional properties of the target object as kind-relevant, guiding infants' categorization of the foldable cup as a cup, despite it looking like a plate. These results suggest that infants likely encode familiar objects as exemplars of their kind and that ostensive communication can play a crucial role in disambiguating what kind an object belongs to, even when this requires disregarding salient surface features.

Out of your sight, out of my mind: Knowledge about another person's visual access modulates spontaneous visuospatial perspective-taking.

Accumulating evidence suggests that humans spontaneously adopt each other's visuospatial perspective (VSP), but many aspects about the underlying mechanisms remain unknown. The aim of this study was to investigate whether knowledge about another's visual access systematically modulates spontaneous VSP-taking. In a spatial compatibility task, a participant and a confederate sat at a 90°angle to each other, with visual stimuli being aligned vertically for the participants and horizontally for the confederate. In this task, VSP-taking is reflected in a spatial compatibility effect in the participant, because stimulus-response compatibility occurs only if the participant takes the confederate's perspective. We manipulated the visual access of the confederate during the task by means of glasses with adjustable shutters that allowed or prevented the confederate from seeing the visual stimuli. The results of 2 experiments showed that people only adopted their task partner's VSP if that person had unhindered visual access to the stimuli. Provided that the confederate had visual access to the participant's stimuli, VSP-taking occurred regardless of whether the confederate performed the same visual task as the participant (Experiment 1) or a different, auditory task (Experiment 2). The results suggest that knowledge about another's visual access is pivotal for triggering spontaneous VSP-taking, whereas having the same task is not. We discuss the possibility that spontaneous VSP-taking can effectively facilitate spatial alignment processes in social interaction. (PsycINFO Database Record

When do humans spontaneously adopt another's visuospatial perspective?

Perspective-taking is a key component of social interactions. However, there is an ongoing controversy about whether, when and how instances of spontaneous visuospatial perspective-taking occur. The aim of this study was to investigate the underlying factors as well as boundary conditions that characterize the spontaneous adoption of another person's visuospatial perspective (VSP) during social interactions. We used a novel paradigm, in which a participant and a confederate performed a simple stimulus-response (SR) compatibility task sitting at a 90° angle to each other. In this set-up, participants would show a spatial compatibility effect only if they adopted the confederate's VSP. In a series of 5 experiments we found that participants reliably adopted the VSP of the confederate, as long as he was perceived as an intentionally acting agent. Our results therefore show that humans are able to spontaneously adopt the differing VSP of another agent and that there is a tight link between perspective-taking and performing actions together. The results suggest that spontaneous VSP-taking can effectively facilitate and speed up spatial alignment processes accruing from dynamic interactions in multiagent environments.

Pointing as Epistemic Request: 12-month-olds Point to Receive New Information.

Infants start pointing systematically to objects or events around their first birthday. It has been proposed that infants point to an event in order to share their appreciation of it with others. In the current study, we tested another hypothesis, according to which infants' pointing could also serve as an epistemic request directed to the adult. Thus, infants' motivation for pointing could include the expectation that adults would provide new information about the referent. In two experiments, an adult reacted to 12-month-olds' pointing gestures by exhibiting 'informing' or 'sharing' behavior. In response, infants pointed more frequently across trials in the informing than in the sharing condition. This suggests that the feedback that contained new information matched infants' expectations more than mere attention sharing. Such a result is consistent with the idea that not just the comprehension but also the production of early communicative signals is tuned to assist infants' learning from others.