Infants infer intentions from prosody

Two studies were conducted to examine infants’ ability to discern intentions from lexical and prosodic cues. Two groups of 14-18-month-olds participated in these studies. In both studies, infants watched an adult perform a sequence of two-step actions on novel toys that produced an end-result. In the first study actions were marked intentionally with both lexical and prosodic cues. In the second study, the lexical markers of intention were presented in Greek, thus providing infants with prosodic but not lexical cues. In both studies, infants reproduced more intentional than accidental actions, suggesting that infants can infer intentions from prosodic cues.     

Apes know that hidden objects can affect the orientation of other objects

Four bonobos, seven gorillas, and six orangutans were presented with two small rectangular boards on a platform. One of the boards had a piece of food under it so that it acquired an inclined orientation whereas the other remained flat on the platform. Subjects preferentially selected the inclined board. In another experiment, subjects were initially presented with two inclined boards and a transformation took place in which one of the boards fell flat to the platform while the other remained inclined. Subjects also preferred the board that remained inclined. Two additional experiments highlighted some of the possible limitations of their reasoning in this task. Presented with two inclined boards, one of which was visibly supported by a piece of wood, they failed to systematically select the unsupported one whose only reason for being inclined was the presence of the reward. Another experiment presented two rewards in each trial (instead of the customary one) in one of the following two combinations: large banana vs. small carrot or small banana vs. large carrot. Prior to the test, E presented both rewards to the subject and then hid each of them under one of the boards so that both boards were differentially inclined due to the different sizes of the rewards involved. Although subjects selected the board that showed a greater inclination (thus securing the larger reward), they disregarded the type of food that was involved. This often meant that they chose the large carrot over the small banana even though they reversed such a choice when the rewards were not occluded by the boards. Providing subjects with a 'reminder' of the type of reward hidden under the boards did not alter the original results. There was no evidence of learning throughout the various experiments and control tests ruled out the possibility of inadvertent cuing by the experimenter, poor performance due to a lack of motivation, or good performance due to a predisposition to select objects with sloped surfaces. It is concluded that subjects made some inferences about the reason for the inclined orientation of the boards, and not simply associated an inclined orientation with the presence of the reward.     

Intentional control of visual processing benefits from referential objects

Arguments have been made that enhanced visual processing occurs in the area of the palms of the hands due to greater density of bimodal neurons. An alternative is that the hands serve as reference objects relative to which attentional resources are allocated. Two experiments were conducted to determine whether the palms are unique in speeding responses in an Eriksen flanker-type task compared with other parts of the hands and objects used as barriers. In Experiment 1, the hands were crossed and positioned so that the palms faced outward toward letters located in the outer positions. Trial blocks differed in whether the centrally located letter or outer letters were designated as the target for responding. Results yielded reductions in flanker interference much as obtained when the palms face inward. This reduction occurred regardless of whether the center or outer positions of the letters were designated as the target. Experiment 2 replicated these results using as reference objects wooden blocks that mimicked the hands' physical contours, positioned with a curve-edge facing outwards. The results lend support to the referential coding account of the reduction of flanker interference.     

Understanding the referential nature of looking: infants' preference for object-directed gaze

In four experiments, we investigated whether 9-month-old infants are sensitive to the relationship between gaze direction and object location and whether this sensitivity depends on the presence of communicative cues like eye contact. Infants observed a face, which repeatedly shifted its eyes either toward, or away from, unpredictably appearing objects. We found that they looked longer at the face when the gaze shifts were congruent with the location of the object. A second experiment ruled out that this effect was simply due to spatial congruency, while a third and a fourth experiment revealed that a preceding period of eye contact is required to elicit the gaze-object congruency effect. These results indicate that infants at this age can encode eye direction in referential terms in the presence of communication cues and are biased to attend to scenes with object-directed gaze.     

Infants learn about objects from statistics and people

In laboratory experiments, infants are sensitive to patterns of visual features that co-occur (e.g., Fiser & Aslin, 2002). Once infants learn the statistical regularities, however, what do they do with that knowledge? Moreover, which patterns do infants learn in the cluttered world outside of the laboratory? Across 4 experiments, we show that 9-month-olds use this sensitivity to make inferences about object properties. In Experiment 1, 9-month-old infants expected co-occurring visual features to remain fused (i.e., infants looked longer when co-occurring features split apart than when they stayed together). Forming such expectations can help identify integral object parts for object individuation, recognition, and categorization. In Experiment 2, we increased the task difficulty by presenting the test stimuli simultaneously with a different spatial layout from the familiarization trials to provide a more ecologically valid condition. Infants did not make similar inferences in this more distracting test condition. However, Experiment 3 showed that a social cue did allow inferences in this more difficult test condition, and Experiment 4 showed that social cues helped infants choose patterns among distractor patterns during learning as well as during test. These findings suggest that infants can use feature co-occurrence to learn about objects and that social cues shape such foundational learning in distraction-filled environments.     

Children's use of gaze and limb movement cues to infer deception

A sample of 96 children from kindergarten, 2nd, 4th, and 6th grades judged the truthfulness of peers who varied in gaze and limb movement while providing verbal communications. Results indicated that children attributed greater lying to the peers who displayed indirect rather than direct gaze and active rather than nonactive limb movement. The use of these cues was more evident in 4th- and 6th-grade children than it was in kindergarten and 2nd-grade children. Pilot studies indicated that adults and children as young as 5-6 years of age associated indirect gaze and active limb movement with anxiety. The findings are discussed with respect to children's theory of mind, concepts of lying, understanding of display rules, and learning of physiological cues associated with deception.     

Development of gaze aversion as disengagement from visual information

Older children, but not younger children, were found to look away more from the face of an interlocutor when answering difficult as opposed to easy questions. Similar results were found in earlier work with adults, who often avert their gaze during cognitively difficult tasks (A. M. Glenberg, J. L. Schroeder, & D. A. Robertson, 1998). Twenty-five 8-year-olds and 26 5-year-olds answered verbal reasoning and arithmetic questions of varying difficulty. The older children increased gaze aversion from the face of the adult questioner in response to both difficult verbal reasoning questions and difficult arithmetic questions. In contrast, younger children (5-year-olds) responded less consistently to cognitive difficulty. It is concluded that adultlike patterns of gaze aversion in response to cognitive difficulty are certainly acquired by 8 years of age. The implications of appropriate gaze aversion for children's management of cognitive processing resources are considered.     

The functional arrangement of objects biases gaze direction

Psychonomic Bulletin & Review - A growing number of studies suggest that semantic knowledge can influence the control of gaze in scenes. For example, observers are more likely to look toward...     

Holistic face processing can be independent of gaze behaviour: Evidence from the composite face illusion

People tend to perceive identical top halves (i.e. above the nose) of two face stimuli as being different when they are aligned with distinct bottom halves. This composite face illusion is generally considered as the most compelling evidence that facial features are integrated into a holistic representation. Here, we recorded eye‐movements during the composite face illusion in a delayed matching task of top halves of faces. Behavioural results showed a strong composite face effect, participants making more mistakes and taking longer time to match two identical top halves of faces when they were aligned (vs. misaligned) with different bottom halves. Importantly, fixation sites and eye‐movements were virtually identical when the top and bottom parts were aligned (composite illusion) or misaligned (no illusion), indicating that holistic face processing can be independent of gaze behaviour. These findings reinforce the view that holistic representations of individual faces can be extracted early on from information at a relatively coarse scale, independently of overt attention.     

Human heading judgments in the presence of moving objects

When moving toward a stationary scene, people judge their heading quite well from visual information alone. Much experimental and modeling work has been presented to analyze how people judge their heading for stationary scenes. However, in everyday life, we often move through scenes that contain moving objects. Most models have difficulty computing heading when moving objects are in the scene, and few studies have examined how well humans perform in the presence of moving objects. In this study, we tested how well people judge their heading in the presence of moving objects. We found that people perform remarkably well under a variety of conditions. The only condition that affects an observer’s ability to judge heading accurately consists of a large moving object crossing the observer’s path. In this case, the presence of the object causes a small bias in the heading judgments. For objects moving horizontally with respect to the observer, this bias is in the object’s direction of motion. These results present a challenge for computational models.     

Perceiving curvilinear heading in the presence of moving objects

Four experiments were directed at understanding the influence of multiple moving objects on curvilinear (i.e., circular and elliptical) heading perception. Displays simulated observer movement over a ground plane in the presence of moving objects depicted as transparent, opaque, or black cubes. Objects either moved parallel to or intersected the observer's path and either retreated from or approached the moving observer. Heading judgments were accurate and consistent across all conditions. The significance of these results for computational models of heading perception and for information in the global optic flow field about observer and object motion is discussed.     

Experience matters: 11-month-old infants can learn to use material information to predict the weight of novel objects

In contrast to previous findings, this study demonstrates that 11-month-old infants are able to learn the relationship between object material and object weight when exploring different objects that provided a systematic covariation of both object features. This guides their action in a subsequent preferential-reaching task.     

Young infants' reasoning about hidden objects: evidence from violation-of-expectation tasks with test trials only

The present research examined alternative accounts of prior violation-of-expectation (VOE) reports that young infants can represent and reason about hidden objects. According to these accounts, young infants' apparent success in these VOE tasks reflects only novelty and familiarity preferences induced by the habituation or familiarization trials in the tasks. In two experiments, 4-month-old infants were tested in VOE tasks with test trials only. The infants still gave evidence that they could represent and reason about hidden objects: they were surprised, as indicated by greater attention, when a wide object became fully hidden behind a narrow occluder (Experiment 1) or inside a narrow container (Experiment 2). These and control results demonstrate that young infants can succeed at VOE tasks involving hidden objects even when given no habituation or familiarization trials. The present research thus provides additional support for the conclusion that young infants possess expectations about hidden objects. Methodological issues concerning the use of habituation or familiarization trials in VOE tasks are also discussed.     

Affective evaluations of objects are influenced by observed gaze direction and emotional expression

Gaze direction signals another person's focus of interest. Facial expressions convey information about their mental state. Appropriate responses to these signals should reflect their combined influence, yet current evidence suggests that gaze-cueing effects for objects near an observed face are not modulated by its emotional expression. Here, we extend the investigation of perceived gaze direction and emotional expression by considering their combined influence on affective judgments. While traditional response-time measures revealed equal gaze-cueing effects for happy and disgust faces, affective evaluations critically depended on the combined product of gaze and emotion. Target objects looked at with a happy expression were liked more than objects looked at with a disgust expression. Objects not looked at were rated equally for both expressions. Our results demonstrate that facial expression does modulate the way that observers utilize gaze cues: Objects attended by others are evaluated according to the valence of their facial expression.     

Invariant recognition of natural objects in the presence of shadows

Shadows are frequently present when we recognize natural objects, but it is unclear whether they help or hinder recognition. Shadows could improve recognition by providing information about illumination and 3-D surface shape, or impair recognition by introducing spurious contours that are confused with object boundaries. In three experiments, we explored the effect of shadows on recognition of natural objects. The stimuli were digitized photographs of fruits and vegetables displayed with or without shadows. In experiment 1, we evaluated the effects of shadows, color, and image resolution on naming latency and accuracy. Performance was not affected by the presence of shadows, even for gray-scale, blurry images, where shadows are difficult to identify. In experiment 2, we explored recognition of two-tone images of the same objects. In these images, shadow edges are difficult to distinguish from object and surface edges because all edges are defined by a luminance boundary. Shadows impaired performance, but only in the early trials. In experiment 3, we examined whether shadows have a stronger impact when exposure time is limited, allowing little time for processing shadows; no effect of shadows was found. These studies show that recognition of natural objects is highly invariant to the complex luminance patterns caused by shadows.     

Spatial encoding of hidden objects in dogs (Canis familiaris)

The authors investigated the type of spatial information that controls domestic dogs' (Canis familiaris) search behavior in a situation in which they have to locate a spatial position where they saw an object move and disappear. In Experiments 1 and 2, the authors manipulated all local and global sources of allocentric spatial information surrounding the hiding location. The results revealed that dogs relied on an egocentric frame of reference. Experiment 3 showed that dogs also encoded allocentric information when egocentric information was irrelevant. The authors conclude that dogs simultaneously encode both egocentric and allocentric spatial information to locate a spatial position, but they primarily base their search behavior on an egocentric frame of reference. The authors discuss under which natural conditions dogs might use these 2 sources of spatial information and detail the nature of spatial egocentric information and the circumstances underlying its use by dogs.     

The importance of context information for the spatial specificity of gaze cueing

In three experiments, we investigated the spatial allocation of attention in response to central gaze cues. In particular, we examined whether the allocation of attentional resources is influenced by context information—that is, the presence or absence of reference objects (i.e., placeholders) in the periphery. On each trial, gaze cues were followed by a target stimulus to which participants had to respond by keypress or by performing a target-directed saccade. Targets were presented either in an empty visual field (Exps. 1 and 2) or in previewed location placeholders (Exp. 3) and appeared at one of either 18 (Exp. 1) or six (Exps. 2 and 3) possible positions. The spatial distribution of attention was determined by comparing response times as a function of the distance between the cued and target positions. Gaze cueing was not specific to the exact cued position, but instead generalized equally to all positions in the cued hemifield, when no context information was provided. However, gaze direction induced a facilitation effect specific to the exact gazed-at position when reference objects were presented. We concluded that the presence of possible objects in the periphery to which gaze cues could refer is a prerequisite for attention shifts being specific to the gazed-at position.     

Slow and steady: sustained effects of lexico-semantic associations can mediate referential impairments in schizophrenia

The present study investigated the contribution of lexico-semantic associations to impairments in establishing reference in schizophrenia. We examined event-related potentials as schizophrenia patients and healthy, demographically matched controls read five-sentence scenarios. Sentence 4 introduced a noun that referred back to three possible referents introduced in Sentences 1–3. These referents were contextually appropriate, contextually inappropriate but lexico-semantically associated, and contextually inappropriate and lexico-semantically nonassociated. In order to determine whether participants had correctly linked the anaphor to its referent, the final sentence reintroduced each referent, and participants indicated whether the last two sentences referred to the same entity. Results indicated that between 300 and 400 ms, patients, like healthy controls, used discourse context to link the noun with its preceding referent. However, between 400 and 500 ms, neural activity in patients was modulated only by lexico-semantic associations, rather than by discourse context. Moreover, patients were also more likely than controls to incorrectly link the noun with contextually inappropriate but lexico-semantically associated referents. These results suggest that at least some types of referential impairments may be driven by sustained activation of contextually inappropriate lexico-semantic associations.