Object identification in preschool children and adults

We introduce computer-based methodologies for investigating object identification in 3- to 5-year-old children. In two experiments, preschool children and adults indicated when they could identify degraded pictures of common objects as those pictures either gradually improved or degraded in clarity. Clarity transformations were implemented in four ways: blurring, decreasing the picture's physical size, decreasing the pixel signal-to-noise ratio, and cropping. In Experiment 1, all age groups correctly identified objects at a more degraded state when those objects began moderately, as opposed to very, degraded and then clarified. This finding supports the notion that previous perceptual hypotheses interfere with object identification (i.e. the perceptual interference effect). In Experiment 2, children, but not adults, overestimated their ability to recognize objects in a degraded state when the object's identity was given to them beforehand. This suggests that for young children knowledge of the object's true identity cannot be ignored when evaluating their current perceptions. This is the first demonstration of the perceptual interference effect in children. We discuss both methodological and theoretical implications of the findings for research on object perception and theory of mind.

Pre-attack symptomatology and temperament as predictors of children's responses to the September 11 terrorist attacks

BACKGROUND

The aims of this study were to assess the psychological response of children following the September 11, 2001 terrorist attacks in New York and Washington, DC and to examine prospective predictors of children's post-attack responses.

METHOD

Children's responses were assessed in a community sample of children in Seattle, Washington, participating in an ongoing study. Symptomatology and temperament assessed prior to the attacks were examined as prospective predictors of post-attack post-traumatic stress (PTS), anxiety, depression and externalizing problems.

RESULTS

Children demonstrated PTS symptoms and worries at levels comparable to those in children directly experiencing disasters, with 77% of children reporting being worried, 68% being upset by reminders, and 39% having upsetting thoughts. The most common PTS symptom cluster was re-experiencing, and 8% of children met criteria consistent with PTSD. African-American children reported more avoidant PTS symptoms and being more upset by the attacks than European-American children. Girls reported being more upset than boys. Prior internalizing, externalizing, social competence and self-esteem were related to post-attack PTS; and child inhibitory control, assessed prior to the 9/11 attacks, demonstrated a trend towards an association with post-attack PTS symptoms controlling for prior levels of symptomatology. PTS predicted child-report anxiety and conduct problem symptoms at follow-up, approximately 6 months after 9/11.

CONCLUSIONS

Children experiencing a major disaster at a distance or indirectly through media exposure demonstrated worries and PTS symptoms suggesting that communities need to attend to children's mental health needs in response to national or regional disasters. Pre-disaster symptomatology or low self-regulation may render children more vulnerable in response to a disaster, and immediate post-disaster responses predict subsequent symptomatology. These variables might be used in the identification of children in need of intervention.

Brain Activation during Face Perception: Evidence of a Developmental Change

Behavioral studies suggest that children under age 10 process faces using a piecemeal strategy based on individual distinctive facial features, whereas older children use a configural strategy based on the spatial relations among the face's features. The purpose of this study was to determine whether activation of the fusiform gyrus, which is involved in face processing in adults, is greater during face processing in older children (12–14 years) than in younger children (8– 10 years). Functional MRI scans were obtained while children viewed faces and houses. A developmental change was observed: Older children, but not younger children, showed significantly more activation in bilateral fusiform gyri for faces than for houses. Activation in the fusiform gyrus correlated significantly with age and with a behavioral measure of configural face processing. Regions believed to be involved in processing basic facial features were activated in both younger and older children. Some evidence was also observed for greater activation for houses versus faces for the older children than for the younger children, suggesting that processing of these two stimulus types becomes more differentiated as children age. The current results provide biological insight into changes in visual processing of faces that occur with normal development.

How do we perceive the pain of others? A window into the neural processes involved in empathy

To what extent do we share feelings with others? Neuroimaging investigations of the neural mechanisms involved in the perception of pain in others may cast light on one basic component of human empathy, the interpersonal sharing of affect. In this fMRI study, participants were shown a series of still photographs of hands and feet in situations that are likely to cause pain, and a matched set of control photographs without any painful events. They were asked to assess on-line the level of pain experienced by the person in the photographs. The results demonstrated that perceiving and assessing painful situations in others was associated with significant bilateral changes in activity in several regions notably, the anterior cingulate, the anterior insula, the cerebellum, and to a lesser extent the thalamus. These regions are known to play a significant role in pain processing. Finally, the activity in the anterior cingulate was strongly correlated with the participants' ratings of the others' pain, suggesting that the activity of this brain region is modulated according to subjects' reactivity to the pain of others. Our findings suggest that there is a partial cerebral commonality between perceiving pain in another individual and experiencing it oneself. This study adds to our understanding of the neurological mechanisms implicated in intersubjectivity and human empathy.

An fMRI study of imitation: action representation and body schema

Recent neuropsychological investigations of apraxia have led to new hypotheses about the representational defects associated with imitation impairments in neurological patients. This fMRI experiment investigated the relation between imitation and the body schema in healthy subjects. Experimental conditions were derived from a factorial plan, and participants were asked to watch a human model performing bodily gestures and then to execute either an identical or a different action, with the same or different limbs. Brain areas activated when subjects imitated the model were traced to the representation of the action (main effect of performing an identical action regardless of limb), to the body schema (using the same limb regardless of action), or to both. The first set of analyses yielded a network associated with visual perception, indicating that action representation is primarily visuospatial not motor, while the second analysis highlighted regions involved in body schema including the inferior parietal cortex and the insula. It is suggested that imitation of simple body gestures requires both a visuospatial description of the observed model, sustained by visual perception areas in the right occipitotemporal and superior parietal cortices and a visuospatial description of one's own body, supported by the left inferior parietal lobule. These results favor a model of praxis proposing that imitation deficits in left inferior parietal lobe patients with apraxia reflect primarily an impairment of the body schema, while deficits of praxis in right parietal patients are limited to gestures demanding in terms of visuospatial analysis.

The neural bases of cooperation and competition: an fMRI investigation

Cooperation and competition are two basic modes of social cognition that necessitate monitoring of both one's own and others' actions, as well as adopting a specific mental set. In this fMRI, study individuals played a specially designed computer game, according to a set of predefined rules, either in cooperation with or in competition against another person. The hemodynamic response during these conditions was contrasted to that of the same subjects playing the game independently. Both cooperation and competition stances resulted in activation of a common frontoparietal network subserving executive functions, as well as the anterior insula, involved in autonomic arousal. Moreover, distinct regions were found to be selectively associated with cooperation and competition, notably the orbitofrontal cortex in the former and the inferior parietal and medial prefrontal cortices in the latter. This pattern reflects the different mental frameworks implicated in being cooperative versus competitive with another person. In accordance with evidence from evolutionary psychology as well as from developmental psychology, we argue that cooperation is a socially rewarding process and is associated with specific left medial orbitofrontal cortex involvement.

Object permanence after a 24-hr delay and leaving the locale of disappearance: the role of memory, space, and identity

Fourteen-month-old infants saw an object hidden inside a container and were removed from the disappearance locale for 24 hr. Upon their return, they searched correctly for the hidden object, demonstrating object permanence and long-term memory. Control infants who saw no disappearance did not search. In Experiment 2, infants returned to see the container either in the same or a different room. Performance by room-change infants dropped to baseline levels, suggesting that infant search for hidden objects is guided by numerical identity. Infants seek the individual object that disappeared, which exists in its original location, not in a different room. A new behavior, identity-verifying search, was discovered and quantified. Implications are drawn for memory, spatial understanding, object permanence, and object identity.

The importance of eyes: how infants interpret adult looking behavior

Two studies assessed the gaze following of 12-, 14-, and 18-month-old infants. The experimental manipulation was whether an adult could see the targets. In Experiment 1, the adult turned to targets with either open or closed eyes. Infants at all ages looked at the adult's target more in the open- versus closed-eyes condition. In Experiment 2, an inanimate occluder, a blindfold, was compared with a headband control. Infants 14- and 18-months-old looked more at the adult's target in the headband condition. Infants were not simply responding to adult head turning, which was controlled, but were sensitive to the status of the adult's eyes. In the 2nd year, infants interpreted adult looking as object-directed--an act connecting the gazer and the object.

What imitation tells us about social cognition: a rapprochement between developmental psychology and cognitive neuroscience

Both developmental and neurophysiological research suggest a common coding between perceived and generated actions. This shared representational network is innately wired in humans. We review psychological evidence concerning the imitative behaviour of newborn human infants. We suggest that the mechanisms involved in infant imitation provide the foundation for understanding that others are 'like me' and underlie the development of theory of mind and empathy for others. We also analyse functional neuroimaging studies that explore the neurophysiological substrate of imitation in adults. We marshal evidence that imitation recruits not only shared neural representations between the self and the other but also cortical regions in the parietal cortex that are crucial for distinguishing between the perspective of self and other. Imitation is doubly revealing: it is used by infants to learn about adults, and by scientists to understand the organization and functioning of the brain.

Age-related differences in neural correlates of face recognition during the toddler and preschool years

Research on the development of face recognition in infancy has shown that infants respond to faces as if they are special and recognize familiar faces early in development. Infants also show recognition and differential attachment to familiar people very early in development. We tested the hypothesis that infants' responses to familiar and unfamiliar faces differ at different ages. Specifically, we present data showing age-related changes in infants' brain responses to mother's face versus a stranger's face in children between 18 and 54 months of age. We propose that these changes are based on age-related differences in the perceived salience of the face of the primary caregiver versus strangers.

The importance of eyes: how infants interpret adult looking behavior

Two studies assessed the gaze following of 12-, 14-, and 18-month-old infants. The experimental manipulation was whether an adult could see the targets. In Experiment 1, the adult turned to targets with either open or closed eyes. Infants at all ages looked at the adult's target more in the open- versus closed-eyes condition. In Experiment 2, an inanimate occluder, a blindfold, was compared with a headband control. Infants 14- and 18-months-old looked more at the adult's target in the headband condition. Infants were not simply responding to adult head turning, which was controlled, but were sensitive to the status of the adult's eyes. In the 2nd year, infants interpreted adult looking as object-directed--an act connecting the gazer and the object.

Neural correlates of face and object recognition in young children with autism spectrum disorder, developmental delay, and typical development

This study utilized electroencephalographic recordings to examine whether young children with autism spectrum disorder (ASD) have impaired face recognition ability. High-density brain event-related potentials (ERPs) were recorded to photos of the child's mother's face versus an unfamiliar female face and photos of a favorite versus an unfamiliar toy from children with ASD, children with typical development, and children with developmental delay, all 3 to 4 years of age (N = 118). Typically developing children showed ERP amplitude differences in two components, P400 and Nc, to a familiar versus an unfamiliar face, and to a familiar versus an unfamiliar object. In contrast, children with ASD failed to show differences in ERPs to a familiar versus an unfamiliar face, but they did show P400 and Nc amplitude differences to a familiar versus an unfamiliar object. Developmentally delayed children showed significant ERP amplitude differences for the positive slow wave for both faces and objects. These data suggest that autism is associated with face recognition impairment that is manifest early in life.

Does the end justify the means? A PET exploration of the mechanisms involved in human imitation

Imitation is a natural mechanism involving perception-action coupling which plays a foundational role in human development, in particular to extract the intention from the surface behavior exhibited by others. The aim of this H(15)(2)O PET activation experiment was to investigate the neural basis of imitation of object-oriented actions in normal adults. Experimental conditions were derived from a factorial design. The factors were: (a) is the stimulus event shown to subjects during observation of the model and (b) is the response manipulation performed by the subject. Two key components of human action, the goal and the means to achieve it, were systematically investigated. The results revealed partially overlapping clusters of increased regional cerebral blood flow in the right dorsolateral prefrontal area and in cerebellum when subjects imitated either of the two components. Moreover, specific activity was detected in the medial prefrontal cortex during the imitation of the means, whereas imitating the goal was associated with increased activity in the left premotor cortex. Our results suggest that for normally functioning adults, imitating a gesture activates neural processing of the intention (or goal) underlying the observed action.

A PET exploration of the neural mechanisms involved in reciprocal imitation

Imitation is a natural mechanism involving perception-action coupling which plays a central role in the development of understanding that other people, like the self, are mental agents. PET was used to examine the hemodynamic changes occurring in a reciprocal imitation paradigm. Eighteen subjects (a) imitated the actions of the experimenter, (b) had their actions imitated by the experimenter, (c) freely produced actions, or (d) freely produced actions while watching different actions made by the experimenter. In a baseline condition, subjects simply watched the experimenter's actions. Specific increases were detected in the left STS and in the inferior parietal cortex in conditions involving imitation. The left inferior parietal is specifically involved in producing imitation, whereas the right homologous region is more activated when one's own actions are imitated by another person. This pattern of results suggests that these regions play a specific role in distinguishing internally produced actions from those generated by others.

How the brain perceives causality: an event-related fMRI study

Detection of the causal relationships between events is fundamental for understanding the world around us. We report an event-related fMRI study designed to investigate how the human brain processes the perception of mechanical causality. Subjects were presented with mechanically causal events (in which a ball collides with and causes movement of another ball) and non-causal events (in which no contact is made between the balls). There was a significantly higher level of activation of V5/MT/MST bilaterally, the superior temporal sulcus bilaterally and the left intraparietal sulcus to causal relative to non-causal events. Directing attention to the causal nature of the stimuli had no significant effect on the neural processing of the causal events. These results support theories of causality suggesting that the perception of elementary mechanical causality events is automatically processed by the visual system.

Children's coding of human action: cognitive factors influencing imitation in 3-year-olds

We used imitation as a tool for investigating how young children code action. The study was designed to examine the errors children make in re-enacting manual gestures they see. Thirty-two 3-year-old children served as subjects. Each child was shown 24 gestures, generated by systematically crossing four factors: visual monitoring, spatial endpoint, movement path, and number of hands. The results showed no difference as a function of whether the children could visually monitor their own responses. Interestingly, children made significantly more errors when the adult's action terminated on a body part than they did when the same movement terminated near the body part. There were also significantly more errors when the demonstrated act involved crossing midline than when it did not, and more errors when it involved one hand rather than two hands. Our hypothesis is that human acts are coded in terms of goals. The goals are hierarchically organized, and because young children have difficulty simultaneously integrating multiple goals into one act they often re-enact the goals that are ranked higher, which leads to the errors observed. We argue that imitation is an active reconstruction of perceived events and taps cognitive processing. We suggest that the goal-based imitation in 3-year-olds is a natural developmental outgrowth of the perceptual-motor mapping and goal-directed coding of human acts found in infancy.

Origins of theory of mind, cognition and communication

There has been a revolution in our understanding of infant and toddler cognition that promises to have far-reaching implications for our understanding of communicative and linguistic development. Four empirical findings that helped to prompt this change in theory are analyzed: (a) Intermodal coordination--newborns operate with multimodal information, recognizing equivalences in information across sensory-modalities; (b) Imitation--newborns imitate the lip and tongue movements they see others perform; (c) Memory--young infants form long-lasting representations of perceived events and use these memories to generate motor productions after lengthy delays in novel contexts; (d) Theory of mind--by 18 months of age toddlers have adopted a theory of mind, reading below surface behavior to the goals and intentions in people's actions. This paper examines three views currently being offered in the literature to replace the classical framework of early cognitive development: modularity-nativism, connectionism, and theory-theory. Arguments are marshaled to support the "theory-theory" view. This view emphasizes a combination of innate structure and qualitative reorganization in children's thought based on input from the people and things in their culture. It is suggested that preverbal cognition forms a substrate for language acquisition and that analyzing cognition may enhance our understanding of certain disorders of communication.

Long-term memory, forgetting, and deferred imitation in 12-month-old infants

Long-term recall memory, as indexed by deferred imitation, was assessed in 12-month-old infants. Independent groups of infants were tested after retention intervals of 3 min, 1 week and 4 weeks. Deferred imitation was assessed using the 'observation-only' procedure in which infants were not allowed motor practice on the tasks before the delay was imposed. Thus, the memory could not have been based on re-accessing a motor habit, because none was formed in the first place. After the delay, memory was assessed either in the same or a different environmental context from the one in which the adult had originally demonstrated the acts. In Experiments 1 and 3, infants observed the target acts while in an unusual environment (an orange and white polka-dot tent), and recall memory was tested in an ordinary room. In Experiment 2, infants observed the target acts in their homes and were tested for memory in a university room. The results showed recall memory after all retention intervals, including the 4 week delay, with no effect of context change. Interestingly, the forgetting function showed that the bulk of the forgetting occurred during the first week. The findings of recall memory without motor practice support the view that infants as young as 12 months old use a declarative (nonprocedural) memory system to span delay intervals as long as 4 weeks.

Children with autism fail to orient to naturally occurring social stimuli

Children with autism were compared to developmentally matched children with Down syndrome or typical development in terms of their ability to visually orient to two social stimuli (name called, hands clapping) and two nonsocial stimuli (rattle, musical jack-in-the-box), and in terms of their ability to share attention (following another's gaze or point). It was found that, compared to children with Down syndrome or typical development, children with autism more frequently failed to orient to all stimuli, and that this failure was much more extreme for social stimuli. Children with autism who oriented to social stimuli took longer to do so compared to the other two groups of children. Children with autism also exhibited impairments in shared attention. Moreover, for both children with autism and Down syndrome, correlational analyses revealed a relation between shared attention performance and the ability to orient to social stimuli, but no relation between shared attention performance and the ability to orient to nonsocial stimuli. Results suggest that social orienting impairments may contribute to difficulties in shared attention found in autism.

Neuropsychological correlates of early symptoms of autism

Both the medial temporal lobe and dorsolateral prefrontal cortex have been implicated in autism. In the present study, performance on two neuropsychological tasks--one tapping the medial temporal lobe and related limbic structures, and another tapping the dorsolateral prefrontal cortex--was examined in relation to performance on tasks assessing autistic symptoms in young children with autism, and developmentally matched groups of children with Down syndrome or typical development. Autistic symptoms included orienting to social stimuli, immediate and deferred motor imitation, shared attention, responses to emotional stimuli, and symbolic play. Compared with children with Down syndrome and typically developing children, children with autism performed significantly worse on both the medial temporal lobe and dorsolateral prefrontal tasks, and on tasks assessing symptoms domains. For children with autism, the severity of autistic symptoms was strongly and consistently correlated with performance on the medial temporal lobe task, but not the dorsolateral prefrontal task. The hypothesis that autism is related to dysfunction of the medial temporal lobe and related limbic structures, such as the orbital prefrontal cortex, is discussed.

Explaining Facial Imitation: A Theoretical Model

A long-standing puzzle in developmental psychology is how infants imitate gestures they cannot see themselves perform (facial gestures). Two critical issues are: (a) the metric infants use to detect cross-modal equivalences in human acts and (b) the process by which they correct their imitative errors. We address these issues in a detailed model of the mechanisms underlying facial imitation. The model can be extended to encompass other types of imitation. The model capitalizes on three new theoretical concepts. First, organ identification is the means by which infants relate parts of their own bodies to corresponding ones of the adult's. Second, body babbling (infants' movement practice gained through self-generated activity) provides experience mapping movements to the resulting body configurations. Third, organ relations provide the metric by which infant and adult acts are perceived in commensurate terms. In imitating, infants attempt to match the organ relations they see exhibited by the adults with those they feel themselves make. We show how development restructures the meaning and function of early imitation. We argue that important aspects of later social cognition are rooted in the initial cross-modal equivalence between self and other found in newborns.

Infant vocalizations in response to speech: vocal imitation and developmental change

Infants' development of speech begins with a language-universal pattern of production that eventually becomes language specific. One mechanism contributing to this change is vocal imitation. The present study was undertaken to examine developmental change in infants' vocalizations in response to adults' vowels at 12, 16, and 20 weeks of age and test for vocal imitation. Two methodological aspects of the experiment are noteworthy: (a) three different vowel stimuli (/a/, /i/, and /u/) were videotaped and presented to infants by machine so that the adult model could not artifactually influence infant utterances, and (b) infants' vocalizations were analyzed both physically, using computerized spectrographic techniques, and perceptually by trained phoneticians who transcribed the utterances. The spectrographic analyses revealed a developmental change in the production of vowels. Infants' vowel categories become more separated in vowel space from 12 to 20 weeks of age. Moreover, vocal imitation was documented, infants listening to a particular vowel produced vocalizations resembling that vowel. A hypothesis is advanced extending Kuhl's native language magnet (NLM) model to encompass infants' speech production. It is hypothesized that infants listening to ambient language store perceptually derived representations of the speech sounds they hear which in turn serve as targets for the production of speech utterances. NLM unifies previous findings on the effects of ambient language experience on infants' speech perception and the findings reported here that short-term laboratory experience with speech is sufficient to influence infants' speech production.

Deferred Imitation Across Changes in Context and Object: Memory and Generalization in 14-Month-Old Infants

The influence of changes in context and object characteristics on deferred imitation was assessed in 14-month-old infants. In Experiment 1, infants in the imitation group saw an adult demonstrate target acts on miniature objects in an unusual context (an orange polka-dot tent). When later presented with larger objects in a normal laboratory room, these infants performed significantly more target acts than did controls. In Experiment 2, three groups of infants were tested. Infants in an imitation(no change) group saw an adult demonstrate target acts and were subsequently tested in the same room using the same objects as the adult. Infants in the imitation (context + object size & color change) group followed the same procedure, but both the context and two salient featural characteristics of the objects (size and color) were changed between encoding and the recall test of deferred imitation. Control infants did not see the target demonstrations. Results showed that the combined changes in context and object features led to a significant decrease in imitative performance. Nonetheless, in comparison to the controls, infants exhibited significant recall as indexed by deferred imitation. The results show that imitation generalizes across changes in object size, object color, and test context. The implications for theories of memory and representational development are discussed.