Eighteen- and 24-month-old infants correct others in anticipation of action mistakes

Much of human communication and collaboration is predicated on making predictions about others' actions. Humans frequently use predictions about others' action mistakes to correct others and spare them mistakes. Such anticipatory correcting reveals a social motivation for unsolicited helping. Cognitively, it requires forward inferences about others' actions through mental attributions of goal and reality representations. The current study shows that infants spontaneously intervene when an adult is mistaken about the location of an object she is about to retrieve. Infants pointed out a correct location for an adult before she was about to commit a mistake. Infants did not intervene in control conditions when the adult had witnessed the misplacement, or when she did not intend to retrieve the misplaced object. Results suggest that preverbal infants anticipate a person's mistaken action through mental attributions of both her goal and reality representations, and correct her proactively by spontaneously providing unsolicited information.     

Domesticated dogs’ (Canis familiaris) use of the solidity principle

Organisms must often make predictions about the trajectories of moving objects. However, often these objects become hidden. To later locate such objects, the organism must maintain a representation of the object in memory and generate an expectation about where it will later appear. We explored adult dogs’ knowledge and use of the solidity principle (that one solid object cannot pass through another solid object) by evaluating search behavior. Subjects watched as a treat rolled down an inclined tube into a box. The box either did or did not contain a solid wall dividing it in half. To find the treat, subjects had to modify their search behavior based on the presence or absence of the wall, which either did or did not block the treat’s trajectory. Dogs correctly searched the near location when the barrier was present and the far location when the barrier was absent. They displayed this behavior from the first trial, as well as performed correctly when trial types were intermingled. These results suggest that dogs direct their searches in accordance with the solidity principle.     

Fourteen-month-olds know what others experience only in joint engagement

We investigated how 14‐month‐old infants know what others know. In two studies, an infant played with each of two objects in turn while an experimenter was present. Then the experimenter left the room, and the infant played with a third object with an assistant. The experimenter returned, faced all three objects, and said excitedly ‘Look! Can you give it to me?’ In Study 1, the experimenter experienced each of the first two toys in episodes of joint visual engagement (without manipulation) with the infant. In response to her excited request infants gave the experimenter the object she did not know, thus demonstrating that they knew which ones she knew. In Study 2, infants witnessed the experimenter jointly engage around each of the experienced toys with the assistant, from a third‐person perspective. In response to her request, infants did not give the experimenter the object she had not experienced. In combination with other studies, these results suggest that to know what others have experienced 14‐month‐old infants must do more than just perceive others perceiving something; they must engage with them actively in joint engagement.     

Object files across eye movements: Previous fixations affect the latencies of corrective saccades

One of the factors contributing to a seamless visual experience is object correspondence—that is, the integration of pre- and postsaccadic visual object information into one representation. Previous research had suggested that before the execution of a saccade, a target object is loaded into visual working memory and subsequently is used to locate the target object after the saccade. Until now, studies on object correspondence have not taken previous fixations into account. In the present study, we investigated the influence of previously fixated information on object correspondence. To this end, we adapted a gaze correction paradigm in which a saccade was executed toward either a previously fixated or a novel target. During the saccade, the stimuli were displaced such that the participant’s gaze landed between the target stimulus and a distractor. Participants then executed a corrective saccade to the target. The results indicated that these corrective saccades had lower latencies toward previously fixated than toward nonfixated targets, indicating object-specific facilitation. In two follow-up experiments, we showed that presaccadic spatial and object (surface feature) information can contribute separately to the execution of a corrective saccade, as well as in conjunction. Whereas the execution of a corrective saccade to a previously fixated target object at a previously fixated location is slowed down (i.e., inhibition of return), corrective saccades toward either a previously fixated target object or a previously fixated location are facilitated. We concluded that corrective saccades are executed on the basis of object files rather than of unintegrated feature information.     

Object individuation in 3-day-old chicks: use of property and spatiotemporal information

Object individuation was investigated in newborn domestic chicks. Chicks' spontaneous tendency to approach the larger group of familiar objects was exploited in a series of five experiments. In the first experiment newborn chicks were reared for 3 days with objects differing in either colour, shape or size. At test, each chick was presented with two groups of events: two objects differing in one property vs. two presentations of the same object. In both cases, all objects involved in the same group of events were sequentially presented and eventually concealed in a different spatial location, and the number of events taking place at each location was equalized. Chicks spontaneously approached the two different objects rather than the single object seen twice. Chicks did not just prefer the more varied set as they did not choose it when the two elements of each group of events were simultaneously presented (Experiment 2). Chicks succeeded when two different objects simultaneously presented were confronted with three identical ones simultaneously presented (Experiment 3), though they failed with sequential presentation of two different objects vs. one object presented three times if they had been familiarized with up to three identical objects (Experiment 4). Chicks instead succeeded if they had been familiarized with objects that were all different from one another (Experiment 5). These young birds thus proved able to use property and spatiotemporal information for object individuation.     

Gravity bias in young and adult chimpanzees (Pan troglodytes): tests with a modified opaque-tubes task

Young human children at around 2 years of age fail to predict the correct location of an object when it is dropped from the top of an S-shape opaque tube. They search in the location just below the releasing point (Hood, 1995). This type of error, called a 'gravity bias', has recently been reported in dogs and monkeys. In the present study, we investigated whether young and adult chimpanzees also show such a gravity bias in a modified version of the original opaque-tube task. The original task by Hood and colleagues required the subject to search in a location after the object had fallen, while in the task reported here, subjects were required to predict the location before the object was dropped. Thus the present procedure does not involve explicit invisible displacement operations, one of the important components of the original procedure. In Experiment 1 both young (1.5-2.5-year-old) and adult chimpanzees predicted the location of falling food items below the releasing point even when crossed tubes were used. These gravity errors remained after the extensive experience of using the tubes themselves. Experiment 2 further tested adult and 4-year-old chimpanzees under the set-up in which the straight and crossed tubes were simultaneously presented. The results were the same as those in the previous test, suggesting that developmental changes and learning effect do not affect the gravity bias in chimpanzees.     

Guiding Decision Makers' Eye Movements with (Un)Predictable Object Locations

We propose a new approach for guiding eye movements by controlling the predictability of object locations. We hypothesize that when a high (low) relevance object has a predictable location, observers are more (less) likely to fixate it compared with objects in unpredictable locations. We tested this hypothesis in three decision‐making studies, manipulating the location of a product label in an unpredictable, a predictable, and a mixed visual environment. In Study 1 and Study 2, we find that participants are less likely to fixate a low and medium relevance label in a predictable location, and in Study 3, we find that participants are more likely to fixate a high relevance label in a predictable location. Our findings suggest that predictable locations increase while unpredictable locations decrease top‐down control. The approach can be used to increase or decrease eye movements towards specific information depending on the goals of the choice architect. Copyright © 2017 John Wiley & Sons, Ltd.     

Do domestic dogs interpret pointing as a command?

Domestic dogs comprehend human gestural communication flexibly, particularly the pointing gesture. Here, we examine whether dogs interpret pointing informatively, that is, as simply providing information, or rather as a command, for example, ordering them to move to a particular location. In the first study a human pointed toward an empty cup. In one manipulation, the dog either knew or did not know that the designated cup was empty (and that the other cup actually contained the food). In another manipulation, the human (as authority) either did or did not remain in the room after pointing. Dogs ignored the human’s gesture if they had better information, irrespective of the authority’s presence. In the second study, we varied the level of authority of the person pointing. Sometimes this person was an adult, and sometimes a young child. Dogs followed children’s pointing just as frequently as they followed adults’ pointing (and ignored the dishonest pointing of both), suggesting that the level of authority did not affect their behavior. Taken together these studies suggest that dogs do not see pointing as an imperative command ordering them to a particular location. It is still not totally clear, however, if they interpret it as informative or in some other way.     

Walking through doorways causes forgetting: recall

The aim of the current study was to explore how the location updating effect is affected when people are tested using recall rather than recognition, which is what has been done in prior work. Differences in the memory processes involved with these two tasks lead to predictions for two different patterns of data. In Experiment 1, memory was tested by having participants recall the single object they were carrying or had just put down, whereas in Experiment 2, people sometimes needed to recall both objects. It was found that, unlike recognition test performance, a similar location updating effect was found for both Associated (what was currently being carried) and Dissociated (what was recently set down) objects. Moreover, when both objects were correctly recalled, there was a bias to remember them in the order that they were encountered. Finally, if only one object was correctly recalled, it was the Associated object that was currently being carried. Overall, these results are consistent with the Event Horizon Model of event cognition.     

Infants use shared experience to interpret pointing gestures

We investigated whether 1‐year‐old infants use their shared experience with an adult to determine the meaning of a pointing gesture. In the first study, after two adults had each shared a different activity with the infant, one of the adults pointed to a target object. Eighteen‐ but not 14‐month‐olds responded appropriately to the pointing gesture based on the particular activity they had previously shared with that particular adult. In the second study, 14‐month‐olds were successful in a simpler procedure in which the pointing adult either had or had not shared a relevant activity with the infant prior to the pointing. Infants just beginning to learn language thus already show a complex understanding of the pragmatics of cooperative communication in which shared experience with particular individuals plays a crucial role.     

Representation of object location in 6.5-month-old infants

Within a small bounded space, the location of a hidden object can be coded in terms of distance information, general area of hiding, or the boundary of the space. 6.5-month-old infants' use of these three coding strategies was examined using a visual search task. Infants watched as an object was hidden at one of four identical locations. After a short delay (10 s), the object either reappeared at the location where it was hidden (possible event), or reappeared at one of the other three locations (impossible event). Looking behavior was not systematically influenced by the amount of distance the object moved from the original location of hiding or by whether the object was hidden near a boundary. Infants did not appear to code the location of a hidden object in terms of distance information, general area of hiding, or whether it was hidden at a boundary. However, the location of reappearance (i.e., impossible event) did influence looking times. Infants were surprised when the object reappeared at a boundary position that was previously unoccupied. They were not surprised when the object reappeared at a central location. Thus, two factors influenced coding of location: boundary information (but in a different way than specified) and the nature of the change (absence vs. presence of an object). The influence of these two factors on coding of spatial information was discussed.     

Does contingency in adults’ responding influence 12-month-old infants’ social referencing?

In two experiments we examined the influence of contingent versus non-contingent responding on infant social referencing behavior. EXPERIMENT 1: Forty 12-month-old infants were exposed to an ambiguous toy in a social referencing situation. In one condition an unfamiliar adult who in a previous play situation had responded contingently to the infant’s looks gave the infant positive information about the toy. In the other condition an unfamiliar adult who previously had not responded contingently delivered the positive information. EXPERIMENT 2: Forty-eight 12-month-old infants participated in Experiment 2. In this experiment it was examined whether the familiarity of the adult influences infants’ reactions to contingency in responding. In one condition a parent who previously had responded contingently to the infant’s looks provided positive information about the ambiguous toy, and in the other condition a parent who previously had not responded contingently provided the positive information. The infants looked more at the contingent experimenter in Experimenter 1, and also played more with the toy after receiving positive information from the contingent experimenter. No differences in looking at the parent and in playing with the toy were found in Experiment 2. The results indicate that contingency in responding, as well as the familiarity of the adult, influence infants’ social referencing behavior.     

Orangutans (Pongo pygmaeus) and bonobos (Pan paniscus) point to inform a human about the location of a tool

Although pointing is not part of great apes’ natural gestural repertoire, they can learn to point to food, in order to request it. To assess the flexibility with which they can use this gesture, one can vary the potential referent of the point. In two previous studies, three orangutans (two of them human-reared) have shown the ability to point to the location of a tool which a human experimenter needed in order to give them food. Here, we tested six orangutans and five bonobos using a set-up in which our subjects had to guide a human experimenter to the hiding place of a fork which was needed in order to retrieve a piece of food for the subject out of a vertical tube. We further examined the potential role of a competitive/deceptive context by varying the identity of the person responsible for hiding the tool. In addition, we implemented three different control conditions in which an object was hidden but it was not necessary to indicate its location to get the food. We found that the majority of subjects spontaneously guided the experimenter to the hiding place of the fork by pointing to it when it was necessary and they did so significantly less in control conditions. We did not find an effect of the person hiding the fork. Our results show that mother-reared orangutans and bonobos are able to point to inform a human about the location of an object that the human needs to procure food for the subject and that they can take into account whether it is relevant or not to do so.

Sensitivity to triadic attention between 6 weeks and 3 months of age

In Study 1, 6-week- and 3-month-old infants gazed more to an adult when she alternated attention between an object and the infant versus when attention was directed only to the object. In Study 2, 6-week-olds did not discriminate between triadic situations with face-to-face interaction controlled.     

Does contingency in adults’ responding influence 12-month-old infants’ social referencing?

In two experiments we examined the influence of contingent versus non-contingent responding on infant social referencing behavior. EXPERIMENT 1: Forty 12-month-old infants were exposed to an ambiguous toy in a social referencing situation. In one condition an unfamiliar adult who in a previous play situation had responded contingently to the infant’s looks gave the infant positive information about the toy. In the other condition an unfamiliar adult who previously had not responded contingently delivered the positive information. EXPERIMENT 2: Forty-eight 12-month-old infants participated in Experiment 2. In this experiment it was examined whether the familiarity of the adult influences infants’ reactions to contingency in responding. In one condition a parent who previously had responded contingently to the infant’s looks provided positive information about the ambiguous toy, and in the other condition a parent who previously had not responded contingently provided the positive information. The infants looked more at the contingent experimenter in Experimenter 1, and also played more with the toy after receiving positive information from the contingent experimenter. No differences in looking at the parent and in playing with the toy were found in Experiment 2. The results indicate that contingency in responding, as well as the familiarity of the adult, influence infants’ social referencing behavior.     

Collaborative partner or social tool? New evidence for young children’s understanding of joint intentions in collaborative activities

Some children’s social activities are structured by joint goals. In previous research, the criterion used to determine this was relatively weak: if the partner stopped interacting, did the child attempt to re‐engage her? But re‐engagement attempts could easily result from the child simply realizing that she needs the partner to reach her own goal in the activity (social tool explanation). In two experiments, 21‐ and 27‐month‐old children interacted with an adult in games in which they either did or did not physically need the partner to reach a concrete goal. Moreover, when the partner stopped interacting, she did so because she was either unwilling to continue (breaking off from the joint goal) or unable to continue (presumably still maintaining the joint goal). Children of both age groups encouraged the recalcitrant partner equally often whether she was or was not physically needed for goal attainment. In addition, they did so more often when the partner was unable to continue than when she was unwilling to continue. These findings suggest that young children do not just view their collaborative partners as mindless social tools, but rather as intentional, cooperative agents with whom they must coordinate intentional states.     

Eye tracking provides no evidence that young infants understand path obstruction

In two experiments with 47 4-month-olds, we investigated attention to key aspects of events in which an object moved along a partly occluded path that contained an obstruction. Infants were familiarized with a ball rolling behind an occluder to be revealed resting on an end wall, and on test trials an obstruction wall was placed in the ball's path. In Experiment 1, we did not find longer looking when the object appeared in an impossible location beyond the obstruction, and infants did not selectively fixate the object in this location. In Experiment 2, after rolling one or two balls, we measured infants' fixations of a two-object outcome with one ball in a novel but possible resting position and the other in a familiar but impossible location beyond the obstruction. Infants looked longer at the ball in the possible but novel location, likely reflecting a looking preference for location novelty. Thus we obtained no evidence that infants reasoned about obstruction and identified a violation on that basis.     

Infants’ coding of location in continuous space

The ability to code location in continuous space is fundamental to spatial behavior. Existing evidence indicates a robust ability for such coding by 12 months, but systematic evidence on earlier origins is lacking. A series of studies investigated 5-month-olds’ ability to code the location of an object hidden in a sandbox, using a looking-time paradigm. In Experiment 1, after familiarization with a hiding-and-finding sequence at one location, infants looked longer at an object being disclosed from a location 12 inches (30 cm) away than at an object emerging from the hiding location, showing they were able to code location in continuous space. In Experiment 2, infants reacted with greater looking when objects emerged from locations 8 inches (20 cm) away from the hiding location, showing that location coding was more finely grained than could be inferred based on the first study. In Experiment 3, infants were familiarized with an object shown in hiding-and-finding sequences at two different locations. Infants looked longer at objects emerging 12 inches (30 cm) away from the most recent hiding location than to emergence from the other location, showing that infants could code location even when events had previously occurred at each location. In Experiment 4, after familiarization with two objects with different shapes, colors, and sounding characteristics, shown in hiding-and-finding sequences in two locations, infants reacted to location violations as they had in Experiment 3. However, they did not react to object violations, that is, events in which the wrong object emerged from a hiding location. Experiment 5 also found no effect of object violation, even when the infants initially saw the two objects side by side. Spatiotemporal characteristics may play a more central role in early object individuation than they do later, although further study is required.     

Determinants of infants' understanding of supporting relations: amount of contact versus position of the center of gravity

This study investigated the developmental age at which infants recognize about supporting relations between objects and what information they use to judge whether a supported object will fall down or not. Four kinds of events were used. All events involved support in relation of two boxes, which differed in the amount of contact between objects and the amount of discrepancy between the supported object's position and its most balanced position. 115 infants (3 to 13 mo.) saw 4 events which differed on these two variables. Infants 10 months and older looked longer at the event in which the center of a supported box was just outside of the edge of a supporting box, that is, a support relation in which it was difficult to anticipate whether the box would fall down or not. Analysis suggested that infants' attention is not determined by only one simple stimulus variable but by more complicated variables (such as uncertainty of prediction).     

Walking through doorways causes forgetting: Situation models and experienced space

We investigated the ability of people to retrieve information about objects as they moved through rooms in a virtual space. People were probed withobject names that were either associated withthe person (i.e., carried) or dissociated from the person (i.e., just set down). Also, people either did or did not shift spatial regions (i.e., go to a new room). Information about objects was less accessible when the objects were dissociated from the person. Furthermore, information about an object was also less available when there was a spatial shift. However, the spatial shift had a larger effect on memory for the currently associated object. These data are interpreted as being more supportive of a situation model explanation, following on work using narratives and film. Simpler memory-based accounts that do not take into account the context in which a person is embedded cannot adequately account for the results.