Developmental Science via MedWorm.com

Children's capacity to remember a novel problem and to secure its future solution

Developmental Science — Sat, 20 Mar 2010 00:00:00 +0100

Much of humans' success rests on foresight, the ability to predict what will happen or what is needed in the future. Surprisingly little is known about how this faculty develops. In three experiments (N = 170), 3- and 4-year-old children were presented with simple puzzles. Fifteen minutes later in a different room they were given the opportunity to secure a solution to take back to the puzzle. Only the older children performed above chance, whereas both age groups could solve the task in an instant condition. The same pattern of results emerged for another task involving selection of something to 'feed ' a puppet whose favorite food was initially unavailable. Control conditions suggest that temporal rather than spatial displacement influenced performance. Verbal reports substantiated the c...

Executive functions and child problem behaviors are sensitive to family disruption: a study of children of mothers working overseas

Developmental Science — Thu, 18 Mar 2010 00:00:00 +0100

Mothers in Sri Lanka are increasingly seeking overseas employment, resulting in disruption of the childcare environment. The present study was designed to evaluate the effects of maternal migration on executive function (EF) and behavior, thereby also contributing to the scientific understanding of environmental effects [ndash] or more specifically family effects [ndash] on children's neurocognitive functioning. A sample of 60 healthy 11-year-old children whose mothers had been working overseas for more than 1 year formed the study group, and a comparison group was recruited from the same schools. Evaluations were made twice over a 1-year interval with regard to the EF components inhibition and working memory as well as teacher ratings of internalizing and externalizing behavior. The child...

Piecing together numerical language: children's use of default units in early counting and quantification

Developmental Science — Fri, 12 Mar 2010 00:00:00 +0100

When asked to 'find three forks', adult speakers of English use the noun 'fork' to identify units for counting. However, when number words (e.g. three) and quantifiers (e.g. more, every) are used with unfamiliar words ('Give me three blickets') noun-specific conceptual criteria are unavailable for picking out units. This poses a problem for young children learning language, who begin to use quantifiers and number words by age 2, despite knowing a relatively small number of nouns. Without knowing how individual nouns pick out units of quantification [ndash] e.g. what counts as a blicket[ndash] how could children decide whether there are three blickets or four? Three experiments suggest that children might solve this problem by assigning 'default units' of quantification to number words, qua...

Facial expressions modulate the ontogenetic trajectory of gaze-following among monkeys

Developmental Science — Thu, 11 Mar 2010 00:00:00 +0100

Gaze-following, the tendency to direct one's attention to locations looked at by others, is a crucial aspect of social cognition in human and nonhuman primates. Whereas the development of gaze-following has been intensely studied in human infants, its early ontogeny in nonhuman primates has received little attention. Combining longitudinal and cross-sectional observational data from Barbary macaques at 'La Forêt des Singes', we show here that gaze-following among conspecifics develops within the first year of life with a rapid increase between 5 and 6 months, reaching adult levels at 1 year. Sex, rank, and relatedness of the animal whose gaze the subject followed did not affect gaze-following rates. Interestingly, however, the behavior was enhanced in all age classes if a gaze-cue was acc...

Three-month-olds show a negativity bias in their social evaluations

Developmental Science — Wed, 10 Mar 2010 00:00:00 +0100

Previous research has shown that 6-month-olds evaluate others on the basis of their social behaviors [ndash] they are attracted to prosocial individuals, and avoid antisocial individuals (Hamlin, Wynn & Bloom, 2007). The current studies investigate these capacities prior to 6 months of age. Results from two experiments indicate that even 3-month-old infants evaluate others based on their social behavior towards third parties, and that negative social information is developmentally privileged. (Source: Developmental Science)

Different social motives in the gestural communication of chimpanzees and human children

Developmental Science — Wed, 10 Mar 2010 00:00:00 +0100

Both chimpanzees and human infants use the pointing gesture with human adults, but it is not clear if they are doing so for the same social motives. In two studies, we presented chimpanzees and human 25-month-olds with the opportunity to point for a hidden tool (in the presence of a non-functional distractor). In one condition it was clear that the tool would be used to retrieve a reward for the pointing subject (so the pointing was selfish or 'for-me'), whereas in the other condition it was clear that the tool would be used to retrieve the reward for the experimenter (so the pointing was helpful or 'for-you'). The chimpanzees pointed reliably only when they themselves benefited, whereas the human children pointed reliably no matter who benefited. These results are interpreted as evidence ...

Rise time and formant transition duration in the discrimination of speech sounds: the Ba–Wa distinction in developmental dyslexia

Developmental Science — Wed, 10 Mar 2010 00:00:00 +0100

Across languages, children with developmental dyslexia have a specific difficulty with the neural representation of the sound structure (phonological structure) of speech. One likely cause of their difficulties with phonology is a perceptual difficulty in auditory temporal processing (Tallal, 1980). Tallal (1980) proposed that basic auditory processing of brief, rapidly successive acoustic changes is compromised in dyslexia, thereby affecting phonetic discrimination (e.g. discriminating /b/ from /d/) via impaired discrimination of formant transitions (rapid acoustic changes in frequency and intensity). However, an alternative auditory temporal hypothesis is that the basic auditory processing of the slower amplitude modulation cues in speech is compromised (Goswami et al.,2002). Here, we co...

Children's beliefs about the fantasy/reality status of hypothesized machines

Developmental Science — Fri, 29 Jan 2010 00:00:00 +0100

Four-year-olds, 6-year-olds, and adults were asked to make judgments about the reality status of four different types of machines: real machines that children and adults interact with on a daily basis, real machines that children and adults interact with rarely (if at all), and impossible machines that violated a real-world physical or biological causal law. Adults generally categorized all of the machines accurately. Both groups of children categorized familiar possible machines as real, but were agnostic as to the fantasy status of unfamiliar possible machines. Children generally responded that both kinds of impossible machines were make-believe, but 4-year-olds were more likely to make these accurate judgments for the physical than biological items, different from the older children and...

Not your mother's view: the dynamics of toddler visual experience

Developmental Science — Thu, 28 Jan 2010 00:00:00 +0100

Human toddlers learn about objects through second-by-second, minute-by-minute sensory-motor interactions. In an effort to understand how toddlers' bodily actions structure the visual learning environment, mini-video cameras were placed low on the foreheads of toddlers, and for comparison also on the foreheads of their parents, as they jointly played with toys. Analyses of the head camera views indicate visual experiences with profoundly different dynamic structures. The toddler view often consists of a single dominating object that is close to the sensors and thus that blocks the view of other objects such that individual objects go in and out of view. The adult view, in contrast, is broad and stable, with all potential targets continually in view. These differences may arise for several d...

Seventeen-month-olds appeal to false beliefs to interpret others' referential communication

Developmental Science — Thu, 28 Jan 2010 00:00:00 +0100

Recent studies have demonstrated infants' pragmatic abilities for resolving the referential ambiguity of non-verbal communicative gestures, and for inferring the intended meaning of a communicator's utterances. These abilities are difficult to reconcile with the view that it is not until around 4 years that children can reason about the internal mental states of others. In the current study, we tested whether 17-month-old infants are able to track the status of a communicator's epistemic state and use this to infer what she intends to refer to. Our results show that manipulating whether or not a communicator has a false belief leads infants to different interpretations of the same communicative act, and demonstrate early mental state attribution in a pragmatic context. (Source: Development...

Stable individual differences in number discrimination in infancy

Developmental Science — Mon, 25 Jan 2010 00:00:00 +0100

Previous studies have shown that as a group 6-month-old infants successfully discriminate numerical changes when the values differ by at least a 1:2 ratio but fail at a 2:3 ratio (e.g. 8 vs. 16 but not 8 vs. 12). However, no studies have yet examined individual differences in number discrimination in infancy. Using a novel numerical change detection paradigm, we present more direct evidence that infants' numerical perception is ratio-dependent even within the range of discriminable ratios and thus adheres to Weber's Law. Furthermore, we show that infants' numerical discrimination at 6 months reliably predicts their numerical discrimination abilities but not visual short-term memory at 9 months. Thus, individual differences in numerical discrimination acuity may be stable within the first y...

Statistical learning in typically developing children: the role of age and speed of stimulus presentation

Developmental Science — Mon, 04 Jan 2010 00:00:00 +0100

It is possible that statistical learning (SL) plays a role in almost every mental activity. Indeed, research on SL has grown rapidly over recent decades in an effort to better understand perception and cognition. Yet, there remain gaps in our understanding of how SL operates, in particular with regard to its (im)mutability. Here, we investigated whether participant-related variables (such as age) and task-related variables (such as speed of stimulus presentation) affect visual statistical learning (VSL) in typically developing children. We tested 183 participants ranging in age from 5 to 12 years and compared three speeds of presentation (using stimulus durations of 800, 400 and 200 msecs). A multiple regression analysis revealed significant effects of both age and speed of presentation [n...

Long-lasting memory for an odor acquired at the mother's breast

Developmental Science — Mon, 04 Jan 2010 00:00:00 +0100

This study indicates that early odor memories acquired during breastfeeding can be reactivated and influence behavioral processes until at least toddlerhood. (Source: Developmental Science)

The development of emotional face and eye gaze processing

Developmental Science — Mon, 04 Jan 2010 00:00:00 +0100

Recent research has demonstrated that infants' attention towards novel objects is affected by an adult's emotional expression and eye gaze toward the object. The current event-related potential (ERP) study investigated how infants at 3, 6, and 9 months of age process fearful compared to neutral faces looking toward objects or averting gaze away from objects. Furthermore, we examined how the processing of novel objects is affected by gaze direction and emotional expression. We hypothesized that an adult's fearful expression should be particularly salient when it is directed toward a referent in the environment. Furthermore, responses to objects should be increased if the face previously expressed fear toward the object. Three-month-olds did not show differential neural responses to fearful ...

Mapping numerical processing, reading, and executive functions in the developing brain: an fMRI meta-analysis of 52 studies including 842 children

Developmental Science — Sun, 03 Jan 2010 00:00:00 +0100

Tracing the connections from brain functions to children's cognitive development and education is a major goal of modern neuroscience. We performed the first meta-analysis of functional magnetic resonance imaging (fMRI) data obtained over the past decade (1999[ndash]2008) on more than 800 children and adolescents in three core systems of cognitive development and school learning: numerical abilities, reading, and executive functions (i.e. cognitive control). We ran Activation Likelihood Estimation (ALE) meta-analyses to obtain regions of reliable activity across all the studies. The results indicate that, unlike results usually reported for adults, children primarily engage the frontal cortex when solving numerical tasks. With age, there may be a shift from reliance on the frontal cortex t...

Face scanning distinguishes social from communication impairments in autism

Developmental Science — Sun, 03 Jan 2010 00:00:00 +0100

How closely related are the social and communicative impairments in Autism Spectrum Disorder (ASD)? Recent findings in typically developing children suggest that both types of impairment are highly heritable but have only moderate behavioural and genetic overlap. So far, their respective roles in social perception are poorly understood. Here we show that when looking at other people's faces, children with ASD who are better at socio-emotional behaviours than non-verbal communication look more at the eyes, while those with the opposite profile look more at the mouth (Study 1). For the mouth area, a similar pattern was observed for inverted faces, suggesting that information from this area is perceived on a featural basis. In Study 2, we found that when shown a person performing manual actio...

The development of joint visual attention: a longitudinal study of gaze following during interactions with mothers and strangers

Developmental Science — Sun, 03 Jan 2010 00:00:00 +0100

Two- to 8-month-old infants interacted with their mother or a stranger in a prospective longitudinal gaze following study. Gaze following, as assessed by eye tracking, emerged between 2 and 4 months and stabilized between 6 and 8 months of age. Overall, infants followed the gaze of a stranger more than they followed the gaze of their mothers, demonstrating a stranger preference that emerged between 4 and 6 months of age. These findings do not support the notion that infants acquire gaze following through reinforcement learning. Instead, the findings are discussed with respect to the social cognitive framework, suggesting that young infants are driven by social cognitive motives in their interactions with others. (Source: Developmental Science)

Development of motion processing in children with autism

Developmental Science — Mon, 28 Dec 2009 00:00:00 +0100

Recent findings suggest that children with autism may be impaired in the perception of biological motion from moving point-light displays. Some children with autism also have abnormally high motion coherence thresholds. In the current study we tested a group of children with autism and a group of typically developing children aged 5 to 12 years of age on several motion perception tasks, in order to establish the specificity of the biological motion deficit in relation to other visual discrimination skills. The first task required the recognition of biological from scrambled motion. Three quasi-psychophysical tasks then established individual thresholds for the detection of biological motion in dynamic noise, of motion coherence and of form-from-motion. Lastly, individual thresholds for a t...

Twelve- to 14-month-old infants can predict single-event probability with large set sizes

Developmental Science — Mon, 28 Dec 2009 00:00:00 +0100

Previous research has revealed that infants can reason correctly about single-event probabilities with small but not large set sizes (Bonatti, 2008; Teglas et al., 2007). The current study asks whether infants can make predictions regarding single-event probability with large set sizes using a novel procedure. Infants completed two trials: A preference trial to determine whether they preferred pink or black lollipops and a test trial where infants saw two jars, one containing mostly pink lollipops and another containing mostly black lollipops. The experimenter removed one occluded lollipop from each jar and placed them in two separate opaque cups. Seventy-eight percent of infants searched in the cup that contained a lollipop from the jar with a higher proportion of their preferred color ob...

Neurodevelopmental changes in the circuits underlying empathy and sympathy from childhood to adulthood

Developmental Science — Thu, 17 Dec 2009 00:00:00 +0100

Empathy and sympathy play crucial roles in much of human social interaction and are necessary components for healthy coexistence. Sympathy is thought to be a proxy for motivating prosocial behavior and providing the affective and motivational base for moral development. The purpose of the present study was to use functional MRI to characterize developmental changes in brain activation in the neural circuits underpinning empathy and sympathy. Fifty-seven individuals, whose age ranged from 7 to 40 years old, were presented with short animated visual stimuli depicting painful and non-painful situations. These situations involved either a person whose pain was accidentally caused or a person whose pain was intentionally inflicted by another individual to elicit empathic (feeling as the other) ...

Sex differences in language first appear in gesture

Developmental Science — Tue, 08 Dec 2009 00:00:00 +0100

Children differ in how quickly they reach linguistic milestones. Boys typically produce their first multi-word sentences later than girls do. We ask here whether there are sex differences in children's gestures that precede, and presage, these sex differences in speech. To explore this question, we observed 22 girls and 18 boys every 4 months as they progressed from one-word speech to multi-word speech. We found that boys not only produced speech + speech (S+S) combinations ('drink juice') 3 months later than girls, but they also produced gesture + speech (G+S) combinations expressing the same types of semantic relations ('eat' + point at cookie) 3 months later than girls. Because G+S combinations are produced earlier than S+S combinations, children's gestures provide the first sign that b...

Early development of spatial-numeric associations: evidence from spatial and quantitative performance of preschoolers

Developmental Science — Tue, 08 Dec 2009 00:00:00 +0100

Numeric magnitudes often bias adults' spatial performance. Partly because the direction of this bias (left-to-right versus right-to-left) is culture-specific, it has been assumed that the orientation of spatial-numeric associations is a late development, tied to reading practice or schooling. Challenging this assumption, we found that preschoolers expected numbers to be ordered from left-to-right when they searched for objects in numbered containers, when they counted, and (to a lesser extent) when they added and subtracted. Further, preschoolers who lacked these biases demonstrated more immature, logarithmic representations of numeric value than preschoolers who exhibited the directional bias, suggesting that spatial-numeric associations aid magnitude representations for symbols denoting ...

Medial temporal lobe memory in childhood: developmental transitions

Developmental Science — Tue, 08 Dec 2009 00:00:00 +0100

The medial temporal lobes (MTL) support declarative memory and mature structurally and functionally during the postnatal years in humans. Although recent work has addressed the development of declarative memory in early childhood, less is known about continued development beyond this period of time. The purpose of this investigation was to explore MTL-dependent memory across middle childhood. Children (6 [ndash]10 years old) and adults completed two computerized tasks, place learning (PL) and transitive inference (TI), that each examined relational memory, as well as the flexible use of relational learning. Findings suggest that the development of relational memory precedes the development of the ability to use relational knowledge flexibly in novel situations. Implications for the develop...

Imprinted numbers: newborn chicks' sensitivity to number vs. continuous extent of objects they have been reared with

Developmental Science — Tue, 08 Dec 2009 00:00:00 +0100

Newborn chicks were tested for their sensitivity to number vs. continuous physical extent of artificial objects they had been reared with soon after hatching. Because of the imprinting process, such objects were treated by chicks as social companions. We found that when the objects were similar, chicks faced with choices between 1 vs. 2 or 2 vs. 3 objects chose the set of objects of larger numerosity, irrespective of the number of objects they had been reared with. Moreover, when volume, surface or contour length were controlled for using sets of 1 vs. 4, 1 vs. 6 or 1 vs. 3 objects, chicks resorted to choosing the larger object, rather than the familiar numerosity. When, however, chicks were reared with objects differing in their aspect (colour, size, and shape) and then tested with comple...

'I bet you know more and are nicer too!': what children infer from others' accuracy

Developmental Science — Fri, 13 Nov 2009 00:00:00 +0100

Research has shown that preschoolers monitor others' prior accuracy and prefer to learn from individuals who have the best track record. We investigated the scope of preschoolers' attributions based on an individual's prior accuracy. Experiment 1 revealed that 5-year-olds (but not 4-year-olds) used an individual's prior accuracy at labelling to predict her knowledge of words and broader facts; they also showed a 'halo effect' predicting she would be more prosocial. Experiment 2 confirmed that, overall, 4-year-olds did not make explicit generalizations of knowledge. These findings suggest that an individual's prior accuracy influences older preschoolers' expectations of that individual's broader knowledge as well as their impressions of how she will behave in social interactions. (Source: D...

Increasing task difficulty enhances effects of intersensory redundancy: testing a new prediction of the Intersensory Redundancy Hypothesis

Developmental Science — Thu, 12 Nov 2009 00:00:00 +0100

Prior research has demonstrated intersensory facilitation for perception of amodal properties of events such as tempo and rhythm in early development, supporting predictions of the Intersensory Redundancy Hypothesis (IRH). Specifically, infants discriminate amodal properties in bimodal, redundant stimulation but not in unimodal, nonredundant stimulation in early development, whereas later in development infants can detect amodal properties in both redundant and nonredundant stimulation. The present study tested a new prediction of the IRH: that effects of intersensory redundancy on attention and perceptual processing are most apparent in tasks of high difficulty relative to the skills of the perceiver. We assessed whether by increasing task difficulty, older infants would revert to pattern...

Lexical and articulatory interactions in children's language production

Developmental Science — Thu, 12 Nov 2009 00:00:00 +0100

Traditional models of adult language processing and production include two levels of representation: lexical and sublexical. The current study examines the influence of the inclusion of a lexical representation (i.e. a visual referent and/or object function) on the stability of articulation as well as on phonetic accuracy and variability in typically developing children and children with specific language impairment (SLI). A word learning paradigm was developed so that we could compare children's production with and without lexical representation. The variability and accuracy of productions were examined using speech kinematics as well as traditional phonetic accuracy measures. Results showed that phonetic forms with lexical representation were produced with more articulatory stability tha...

The Ebbinghaus illusion deceives adults but not young children

Developmental Science — Thu, 12 Nov 2009 00:00:00 +0100

The sensitivity of size perception to context has been used to distinguish between 'vision for action' and 'vision for perception', and to study cultural, psychopathological, and developmental differences in perception. The status of that evidence is much debated, however. Here we use a rigorous double dissociation paradigm based on the Ebbinghaus illusion, and find that for children below 7 years of age size discrimination is much less affected by surround size. Young children are less accurate than adults when context is helpful, but more accurate when context is misleading. Even by the age of 10 years context-sensitivity is still not at adult levels. Therefore, size contrast as shown by the Ebbinghaus illusion is not a built-in property of the ventral pathway subserving vision for perce...

Synergies between processing and memory in children's reading span

Developmental Science — Thu, 12 Nov 2009 00:00:00 +0100

We report a study of reading span in 7- to 11-year-old children that addresses several contemporary theoretical issues. We demonstrate that both the timing and the accuracy of recall are affected by the presence or absence of a semantic connection between the processing requirement and the memoranda. Evidence that there can be synergies between processing and memory argues against the view that complex span simply measures the competition between these activities. We also demonstrate a consistent relationship between the rate of completing processing operations (sentence reading) and recall accuracy. At the same time, the shape and strength of this function varies with the task configuration. Taken together, these results demonstrate the potential for reconstructive influences to shape wor...

The role of competition in word learning via referent selection

Developmental Science — Thu, 29 Oct 2009 00:00:00 +0100

Previous research suggests that competition among the objects present during referent selection influences young children's ability to learn words in fast mapping tasks. The present study systematically explored this issue with 30-month-old children. Children first received referent selection trials with a target object and either two, three or four competitor objects. Then, after a short delay, children were tested on their ability to retain the newly fast-mapped names. Overall, the number of competitors did not affect children's ability to form the initial name[ndash]object mappings. However, only children who encountered few competitors during referent selection demonstrated significant levels of retention. Results and implications are discussed in terms of the role of competition in st...

Ophthalmological, cognitive, electrophysiological and MRI assessment of visual processing in preterm children without major neuromotor impairment

Developmental Science — Tue, 27 Oct 2009 00:00:00 +0100

Many studies report chronic deficits in visual processing in children born preterm. We investigated whether functional abnormalities in visual processing exist in children born preterm but without major neuromotor impairment (i.e. cerebral palsy). Twelve such children (< 33 weeks gestation or birthweight < 1000 g) without major neuromotor impairment and 12 born full-term controls were assessed at 8[ndash]12 years of age by means of ophthalmological assessment (visual acuity, colour vision, stereopsis, stereoacuity, visual fields, ocular motility, motor fusion), cognitive tests of visual-motor, visual-perceptual and visual-spatial skills and pattern-reversal visual evoked potentials (PR-VEPs). All participants also underwent magnetic resonance imaging (MRI) of the brain and neuromotor asses...

Selective attention and attention switching: towards a unified developmental approach

Developmental Science — Tue, 13 Oct 2009 23:00:00 +0100

We review and relate two literatures on the development of attention in children: one concerning flexible attention switching and the other concerning selective attention. The first is a growing literature on preschool children's performances in an attention-switching task indicating that children become more flexible in their attentional control during the preschool years. The second literature encompasses a large and robust set of phenomena for the same developmental period that indicates a protracted course of development for selective attention in children. We ask whether developmental changes in processes of selective attention may contribute to more flexible attention switching. We consider the two sets of phenomena with respect to this question and propose an empirical agenda for th...

Individual differences in language development: relationship with motor skill at 21 months

Developmental Science — Tue, 13 Oct 2009 23:00:00 +0100

We examined a variety of motor abilities [ndash] manual gesture including symbolic, meaningless and sequential memory, oral motor control, gross and fine motor control [ndash] in 129 children aged 21 months. Language abilities were assessed and cognitive and socio-economic measures controlled for. Oral motor control was strongly associated with language production (vocabulary and sentence complexity), with some contribution from symbolic abilities. Language comprehension, however, was associated with cognitive and socio-economic measures. We conclude that symbolic, working memory, and mirror neuron accounts of language[ndash]motor control links are limited, but that a common neural and motor substrate for nonverbal and verbal oral movements may drive the motor[ndash]language association. (...

Narrative skill in children with early unilateral brain injury: a possible limit to functional plasticity

Developmental Science — Tue, 13 Oct 2009 23:00:00 +0100

Children with pre- or perinatal brain injury (PL) exhibit marked plasticity for language learning. Previous work has focused mostly on the emergence of earlier-developing skills, such as vocabulary and syntax. Here we ask whether this plasticity for earlier-developing aspects of language extends to more complex, later-developing language functions by examining the narrative production of children with PL. Using an elicitation technique that involves asking children to create stories de novo in response to a story stem, we collected narratives from 11 children with PL and 20 typically developing (TD) children. Narratives were analysed for length, diversity of the vocabulary used, use of complex syntax, complexity of the macro-level narrative structure and use of narrative evaluation. Childr...

Perceived quality of maternal care in childhood and structure and function of mothers' brain

Developmental Science — Wed, 30 Sep 2009 23:00:00 +0100

Animal studies indicate that early maternal care has long-term effects on brain areas related to social attachment and parenting, whereas neglectful mothering is linked with heightened stress reactivity in the hippocampus across the lifespan. The present study explores the possibility, using magnetic resonance imaging, that perceived quality of maternal care in childhood is associated with brain structure and functional responses to salient infant stimuli among human mothers in the first postpartum month. Mothers who reported higher maternal care in childhood showed larger grey matter volumes in the superior and middle frontal gyri, orbital gyrus, superior temporal gyrus and fusiform gyrus. In response to infant cries, these mothers exhibited higher activations in the middle frontal gyrus,...

Executive function and the development of belief–desire psychology

Developmental Science — Tue, 29 Sep 2009 23:00:00 +0100

In two studies children's performance on tasks requiring the ascription of beliefs and desires was investigated in relation to their executive function. Study 1 (n = 80) showed that 3- and 4-year-olds were more proficient at ascribing subjective, mutually incompatible desires and desire-dependent emotions to two persons than they were at ascribing analogous subjective false beliefs. Replicating previous findings, executive function was correlated with false-belief ascription. However, executive function was also correlated with performance on tasks requiring subjective desire understanding. Study 2 (n = 54) replicated these results, and showed that the correlations hold even if age, vocabulary and working memory are controlled for. The results are discussed with regard to the role of execu...

Social categories guide young children's preferences for novel objects

Developmental Science — Mon, 28 Sep 2009 23:00:00 +0100

To whom do children look when deciding on their own preferences? To address this question, 3-year-old children were asked to choose between objects or activities that were endorsed by unfamiliar people who differed in gender, race (White, Black), or age (child, adult). In Experiment 1, children demonstrated robust preferences for objects and activities endorsed by children of their own gender, but less consistent preferences for objects and activities endorsed by children of their own race. In Experiment 2, children selected objects and activities favored by people of their own gender and age. In neither study did most children acknowledge the influence of these social categories. These findings suggest that gender and age categories are encoded spontaneously and influence children's prefe...

Brain activation during upright and inverted encoding of own- and other-age faces: ERP evidence for an own-age bias

Developmental Science — Sun, 27 Sep 2009 23:00:00 +0100

We investigated the neural processing underlying own-age versus other-age faces among 5-year-old children and adults, as well as the effect of orientation on face processing. Upright and inverted faces of 5-year-old children, adults, and elderly adults (> 75 years of age) were presented to participants while ERPs and eye tracking patterns were recorded concurrently. We found evidence for an own-age bias in children, as well as for predicted delayed latencies and larger amplitudes for inverted faces, which replicates earlier findings. Finally, we extend recent reports about an expert-sensitive component (P2) to other-race faces to account for similar effects in regard to other-age faces. We conclude that differences in neural activity are strongly related to the amount and quality of experi...

Effects of Kindermusik training on infants' rhythmic enculturation

Developmental Science — Sun, 27 Sep 2009 23:00:00 +0100

Phillips-Silver and Trainor (2005) demonstrated a link between movement and the metrical interpretation of rhythm patterns in 7-month-old infants. Infants bounced on every second beat of a rhythmic pattern with no auditory accents later preferred to listen to an accented version of the pattern with accents every second beat (duple or march meter), whereas infants bounced on every third beat of the same rhythmic pattern preferred to listen to a version with accents every third beat (triple or waltz meter). The present study compared infants participating in Kindermusik classes with infants not participating in music classes. In Kindermusik classes infants receive enriched experience moving to music. Following Western musical norms, the majority of the music samples in the classes are in dup...

Nonword repetition in children and adults: effects on movement coordination

Developmental Science — Sun, 27 Sep 2009 23:00:00 +0100

Hearing and repeating novel phonetic sequences, or novel nonwords, is a task that taps many levels of processing, including auditory decoding, phonological processing, working memory, speech motor planning and execution. Investigations of nonword repetition abilities have been framed within models of psycholinguistic processing, while the motor aspects, which also are critical for task performance, have been largely ignored. We focused our investigation on both the behavioral and speech motor performance characteristics of this task as performed in a learning paradigm by 9- and 10-year-old children and young adults. Behavioral (percent correct productions) and kinematic (movement duration, lip aperture variability [ndash] an index of the consistency of inter-articulator coordination on rep...

Auditory verb perception recruits motor systems in the developing brain: an fMRI investigation

Developmental Science — Tue, 01 Sep 2009 23:00:00 +0100

This study investigated neural activation patterns during verb processing in children, using fMRI (functional Magnetic Resonance Imaging). Preschool children (aged 4[ndash]6) passively listened to lists of verbs and adjectives while neural activation was measured. Findings indicated that verbs were processed differently than adjectives, as the verbs recruited motor systems in the frontal cortex during auditory perception, but the adjectives did not. Further evidence suggested that different types of verbs activated different regions in the motor cortex. The results demonstrate that the motor system is recruited during verb perception in the developing brain, reflecting the embodied nature of language learning and processing. (Source: Developmental Science)

Analogical reasoning ability in autistic and typically developing children

Developmental Science — Mon, 31 Aug 2009 23:00:00 +0100

Recent studies (e.g. Dawson et al., 2007) have reported that autistic people perform in the normal range on the Raven Progressive Matrices test, a formal reasoning test that requires integration of relations as well as the ability to infer rules and form high-level abstractions. Here we compared autistic and typically developing children, matched on age, IQ, and verbal and non-verbal working memory, using both the Raven test and pictorial tests of analogical reasoning. Whereas the Raven test requires only formal analogical reasoning, the other analogy tests require use of real-world knowledge, as well as inhibition of salient distractors. We found that autistic children performed as well as controls on all these tests of reasoning with relations. Our findings indicate that the basic abilit...

Faces are special for newly hatched chicks: evidence for inborn domain-specific mechanisms underlying spontaneous preferences for face-like stimuli

Developmental Science — Sun, 30 Aug 2009 23:00:00 +0100

It is currently being debated whether human newborns' preference for faces is due to an unlearned, domain-specific and configural representation of the appearance of a face, or to general mechanisms, such as an up-down bias (favouring top-heavy stimuli, which have more elements in their upper part). Here we show that 2-day-old domestic chicks, visually naïve for the arrangement of inner facial features, spontaneously prefer face-like, schematic, stimuli. This preference is maintained when the up-down bias is controlled for (Experiment1) or when put in direct conflict with facedness (Experiment 4). In contrast, we found no evidence for the presence of an up-down bias in chicks (Experiment 2). Moreover, our results indicate that the eye region of stimuli is crucial in determining the expres...

Executive functions in adolescence: inferences from brain and behavior

Developmental Science — Sun, 30 Aug 2009 23:00:00 +0100

Despite the advances in understanding cognitive improvements in executive function in adolescence, much less is known about the influence of affective and social modulators on executive function and the biological underpinnings of these functions and sensitivities. Here, recent behavioral and neuroscientific studies are summarized that have used different approaches (cognition, emotion, individual differences and training) in the study of adolescent executive functions. The combination of these different approaches gives new insight into this complex transitional phase in life, and marks adolescence as not only a period of vulnerabilities, but also great opportunities in terms of training possibilities and interventions. (Source: Developmental Science)

Neural markers of subordinate-level categorization in 6- to 7-month-old infants

Developmental Science — Tue, 18 Aug 2009 23:00:00 +0100

Subordinate-level category-learning processes in infants were investigated with ERP and looking-time measures. ERPs were recorded while 6- to 7-month-olds were presented with Saint Bernard images during familiarization, followed by novel Saint Bernards interspersed with Beagles during test. In addition, infant looking times were measured during a paired-preference test (novel Saint Bernard vs. novel Beagle) conducted at the conclusion of ERP recording. Slow wave activity corresponded with learning a familiarized category at the subordinate and basic levels, whereas Negative central (Nc) and P400 components were linked with novel category preference. The results provide the first evidence identifying the neural markers of subordinate-level categorization observed in looking-time tasks condu...

How is phonological processing related to individual differences in children's arithmetic skills?

Developmental Science — Wed, 12 Aug 2009 23:00:00 +0100

While there is evidence for an association between the development of reading and arithmetic, the precise locus of this relationship remains to be determined. Findings from cognitive neuroscience research that point to shared neural correlates for phonological processing and arithmetic as well as recent behavioral evidence led to the present hypothesis that there exists a highly specific association between phonological awareness and single-digit arithmetic with relatively small problem sizes. The present study examined this association in 37 typically developing fourth and fifth grade children. Regression analyses revealed that phonological awareness was specifically and uniquely related to arithmetic problems with a small but not large problem size. Further analysis indicated that proble...

The interaction between acoustic salience and language experience in developmental speech perception: evidence from nasal place discrimination

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

Previous research suggests that infant speech perception reorganizes in the first year: young infants discriminate both native and non-native phonetic contrasts, but by 10[ndash]12 months difficult non-native contrasts are less discriminable whereas performance improves on native contrasts. In the current study, four experiments tested the hypothesis that, in addition to the influence of native language experience, acoustic salience also affects the perceptual reorganization that takes place in infancy. Using a visual habituation paradigm, two nasal place distinctions that differ in relative acoustic salience, acoustically robust labial-alveolar [ma][ndash][na] and acoustically less salient alveolar-velar [na][ndash][ŋa], were presented to infants in a cross-language design. English...

Something old, something new: a developmental transition from familiarity to novelty preferences with hidden objects

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

Novelty seeking is viewed as adaptive, and novelty preferences in infancy predict cognitive performance into adulthood. Yet 7-month-olds prefer familiar stimuli to novel ones when searching for hidden objects, in contrast to their strong novelty preferences with visible objects (Shinskey & Munakata, 2005). According to a graded representations perspective on object knowledge, infants gradually develop stronger object representations through experience, such that representations of familiar objects can be better maintained, supporting greater search than with novel objects. Object representations should strengthen with further development to allow older infants to shift from familiarity to novelty preferences with hidden objects. The current study tested this prediction by presenting 24 11-...

Categorization, categorical perception, and asymmetry in infants' representation of face race

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

The present study examined whether 6- and 9-month-old Caucasian infants could categorize faces according to race. In Experiment 1, infants were familiarized with different female faces from a common ethnic background (i.e. either Caucasian or Asian) and then tested with female faces from a novel race category. Nine-month-olds were able to form discrete categories of Caucasian and Asian faces. However, 6-month-olds did not form discrete categories of faces based on race. In Experiment 2, a second group of 6- and 9-month-olds was tested to determine whether they could discriminate between different faces from the same race category. Results showed that both age groups could only discriminate between different faces from the own-race category of Caucasian faces. The findings of the two experi...

Using innate visual biases to guide face learning in natural scenes: a computational investigation

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

Newborn infants appear to possess an innate bias that guides preferential orienting to and tracking of human faces. There is, however, no clear agreement as to the underlying mechanism supporting such a preference. In particular, two competing theories (known as the 'structural' and 'sensory' hypotheses) conjecture fundamentally different biasing mechanisms to explain this behavior. The structural hypothesis suggests that a crude '3-dot' representation of face-specific geometry is responsible for the exhibited preference. By contrast, the sensory hypothesis suggests that face preference is the product of several generic visual preferences for qualities like dark/light vertical asymmetry, horizontal symmetry, and high contrast. To complement existing empirical results, the current study des...

The emergence of a novel representation from action: evidence from preschoolers

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

Recent work in embodied cognition has proposed that representations and actions are inextricably linked. The current study examines a developmental account of this relationship. Specifically, we propose that children's actions are foundational for novel representations. Thirty-two preschoolers, aged 3.4 to 5.7 years, were asked to solve a set of simple gear-system problems. Participants' motions and verbalizations were coded to establish the strategies they used. The preschoolers initially solved the problems by simulating the turning and pushing of the gears. Subsequently, most participants discovered a new representation of the problems: the turning direction of the gears alternates. Results show that the number of actions that embodied alternation information, during their simulation of...

Choice latency as a cue for children's subjective confidence in the correctness of their answers

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

Research with adults indicates that confidence in the correctness of an answer decreases as a function of the amount of time it takes to reach that answer, suggesting that people use response latency as a mnemonic cue for subjective confidence. Experiment 1 extended investigation to 2nd, 3rd and 5th graders. When children chose the answer to general knowledge questions, their confidence in the answer was inversely related to choice latency. However, the strength of the relationship increased with grade, suggesting increased reliance with age on the feedback from task performance. The validity of latency as a cue for the accuracy of the answer also increased with age, possibly contributing to the observed age increase in the extent to which confidence judgment discriminated between correct ...

Knowing about not remembering: developmental dissociations in lack-of-memory monitoring

Developmental Science — Tue, 11 Aug 2009 23:00:00 +0100

Children aged 7 and younger encounter great difficulty in assessing whether lack of memory for an event indicates that the event was not experienced. The present research investigated whether this difficulty results from a general inability to evaluate memory absence or from a specific inability to monitor one feature of memory absence that has been examined in previous studies, namely expected memorability. Seven-, 8- and 9-year-olds, and adults (N = 72) enacted, imagined and confabulated about bizarre and common actions. Two weeks later, participants were asked to recognize the actions that had been enacted. Even 7-year-olds monitored the relative familiarity of rejected distracters (i.e. reported higher confidence for the rejection of novel versus imagined and confabulated distracters)....

Two-year-olds are vigilant of others' non-verbal cues to credibility

Developmental Science — Wed, 05 Aug 2009 23:00:00 +0100

Data from three experiments provide the first evidence that children, at least as young as age two, are vigilant of others' non-verbal cues to credibility, and flexibly use these cues to facilitate learning. Experiment 1 revealed that 2- and 3-year-olds prefer to learn about objects from someone who appears, through non-verbal cues, to be confident in performing actions on those objects than from someone who appears uncertain when performing actions on those objects. Experiment 2 revealed that when 2-year-olds observe only one model perform a single action, either confidently or unconfidently, they do not use the model's level of confidence in this single instance to influence their learning. Experiment 3 revealed that 2-year-olds will use a single model's level of confidence to guide thei...

Developmental profiles for multiple object tracking and spatial memory: typically developing preschoolers and people with Williams syndrome

Developmental Science — Tue, 04 Aug 2009 23:00:00 +0100

The ability to track moving objects, a crucial skill for mature performance on everyday spatial tasks, has been hypothesized to require a specialized mechanism that may be available in infancy (i.e. indexes). Consistent with the idea of specialization, our previous work showed that object tracking was more impaired than a matched spatial memory task in individuals with Williams syndrome (WS), a genetic disorder characterized by severe visuo-spatial impairment. We now ask whether this unusual pattern of performance is a reflection of general immaturity or of true abnormality, possibly reflecting the atypical brain development in WS. To examine these two possibilities, we tested typically developing 3- and 4-year-olds and people with WS on multiple object tracking (MOT) and memory for static...

Development of aptitude at altitude

Developmental Science — Tue, 04 Aug 2009 23:00:00 +0100

We describe the physiological, cognitive and behavioural profile of a large cohort of infants (6[ndash]12 months), children (6[ndash]10 years) and adolescents (13[ndash]16 years) who were born and are living at three altitude locations in Bolivia ([sim]500 m, [sim]2500 m and [sim]3700 m). Level of haemoglobin oxygen saturation and end-tidal carbon dioxide were significantly lower in all age groups living above 2500 metres, confirming the presence of hypoxia and hypocapnia, but without any detectable detriment to health. Infant measures of neurodevelopment and behaviour yielded comparable results across altitude groups. Neuropsychological assessment in children and adolescent groups indicated a minor reduction in psychomotor speed with increasing altitude, with no effect of age. This may re...

Use of geometry for spatial reorientation in children applies only to symmetric spaces

Developmental Science — Sun, 02 Aug 2009 23:00:00 +0100

Proponents of the geometric module hypothesis argue that following disorientation, many species reorient by use of macro-environment geometry. It is suggested that attention to the surface layout geometry of natural terrain features may have been selected for over evolutionary time due to the enduring and unambiguous location information it provides. Paradoxically, however, tests of the hypothesis have been exclusively conducted in symmetric (hence 'unnatural' and geometrically ambiguous) environments. The present series of studies examines reorientation by 18-month[ndash]3-year-old children in a rectangular versus irregular quadrilateral enclosure (Study 1), a rectangular versus irregular quadrilateral array (Study 2) and an isosceles versus irregular triangular array (Study 3). Children ...

Differential development of selectivity for faces and bodies in the fusiform gyrus

Developmental Science — Tue, 28 Jul 2009 23:00:00 +0100

Viewing faces or bodies activates category-selective areas of visual cortex, including the fusiform face area (FFA), fusiform body area (FBA), and extrastriate body area (EBA). Here, using fMRI, we investigate the development of these areas, focusing on the right FFA and FBA. Despite the overlap of functionally defined FFA and FBA (54%[ndash]75% overlap), we found that these regions developed along different trajectories. With age (7[ndash]32 years old), the FFA gradually increased in size and selectivity, and was significantly larger and more face-selective in adults than children. By contrast, the size and selectivity of the FBA did not correlate with age, and were equivalent in children and adults. Whereas in adults the FFA and FBA were comparable in size, in children the FBA was on ave...

Representing intentions in self and other: studies of autism and typical development

Developmental Science — Tue, 28 Jul 2009 23:00:00 +0100

This study suggests that individuals with ASD have a diminished awareness of their own and others' intentions and that this diminution is associated with other impairments in theory of mind. (Source: Developmental Science)

The first steps in word learning are easier when the shoes fit: comparing monolingual and bilingual infants

Developmental Science — Tue, 21 Jul 2009 23:00:00 +0100

English, French, and bilingual English-French 17-month-old infants were compared for their performance on a word learning task using the Switch task. Object names presented a /b/ vs. /g/ contrast that is phonemic in both English and French, and auditory strings comprised English and French pronunciations by an adult bilingual. Infants were habituated to two novel objects labeled 'bowce' or 'gowce' and were then presented with a switch trial where a familiar word and familiar object were paired in a novel combination, and a same trial with a familiar word[ndash]object pairing. Bilingual infants looked significantly longer to switch vs. same trials, but English and French monolinguals did not, suggesting that bilingual infants can learn word[ndash]object associations when the phonetic condit...

Spontaneous analog number representations in 3-year-old children

Developmental Science — Mon, 20 Jul 2009 23:00:00 +0100

When enumerating small sets of elements nonverbally, human infants often show a set-size limitation whereby they are unable to represent sets larger than three elements. This finding has been interpreted as evidence that infants spontaneously represent small numbers with an object-file system instead of an analog magnitude system (Feigenson, Dehaene & Spelke, 2004). In contrast, non-human animals and adult humans have been shown to rely on analog magnitudes for representing both small and large numbers (Brannon & Terrace, 1998; Cantlon & Brannon, 2007; Cordes, Gelman, Gallistel & Whalen, 2001). Here we demonstrate that, like adults and non-human animals, children as young as 3 years of age spontaneously employ analog magnitude representations to enumerate both small and large sets. Moreove...

Touch attenuates infants' physiological reactivity to stress

Developmental Science — Mon, 20 Jul 2009 23:00:00 +0100

Animal studies demonstrate that maternal touch and contact regulate infant stress, and handling during periods of maternal deprivation attenuates the stress response. To measure the effects of touch on infant stress reactivity during simulated maternal deprivation, 53 dyads were tested in two paradigms: still-face (SF) and still-face with maternal touch (SF+T). Maternal and infant cortisol levels were sampled at baseline, reactivity, and recovery and mother's and infant's cardiac vagal tone were measured during the free play, still-face, and reunion episodes of the procedure. Cortisol reactivity was higher among infants in the SF condition and while cortisol decreased at recovery for infants in the SF+T, it further increased for those in the SF. Vagal tone showed a greater suppression when...

The role of experience during childhood in shaping the other-race effect

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

It is well known that adults' face recognition is characterized by an 'other-race effect' (ORE; see Meissner & Brigham, 2001), but few studies have investigated this ORE during the development of the face processing system. Here we examined the role of experience with other-race faces during childhood by testing a group of 6- to 14-year-old Asian children adopted between 2 and 26 months in Caucasian families living in Western Europe, as well as a group of age-matched Caucasian children. The latter group showed a strong ORE in favour of own-race faces that was stable from 6 to 14 years of age. The adopted participants did not show a significant reversal of the ORE, unlike a recently reported study (Sangrigoli et al., 2005), but rather comparable results with Asian and Caucasian faces. Their...

Testing the limits of statistical learning for word segmentation

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

In this study, we ask whether infants' ability to track transitional probabilities between syllables in an artificial language can scale up to the challenge of natural language. We do so by testing both 5.5- and 8-month-olds' ability to segment an artificial language containing four words of uniform length (all CVCV) or four words of varying length (two CVCV, two CVCVCV). The transitional probability cues to word boundaries were held equal across the two languages. Both age groups segmented the language containing words of uniform length, demonstrating that even 5.5-month-olds are extremely sensitive to the conditional probabilities in their environment. However, neither age group succeeded in segmenting the language containing words of varying length, despite the fact that the transitiona...

Online usage of theory of mind continues to develop in late adolescence

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

The development of theory of mind use was investigated by giving a computerized task to 177 female participants divided into five age groups: Child I (7.3[ndash]9.7 years); Child II (9.8[ndash]11.4); Adolescent I (11.5[ndash]13.9); Adolescent II (14.0[ndash]17.7); Adults (19.1[ndash]27.5). Participants viewed a set of shelves containing objects, which they were instructed to move by a 'director' who could see some but not all of the objects. Correct interpretation of critical instructions required participants to use the director's perspective and only move objects that the director could see. In a control condition, participants were asked to ignore objects in slots with a grey background. Accuracy improved similarly in both conditions between Child I and Adolescent II. However, while per...

Age differences in the contribution of recollection and familiarity to false-memory formation: a new paradigm to examine developmental reversals

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

Using a new method for studying the development of false-memory formation, we examined developmental differences in the rates at which 6-, 7-, 9-, 10-, and 18-year-olds made two types of memory errors: backward causal-inference errors (i.e. falsely remembering having viewed the non-viewed cause of a previously viewed effect), and gap-filling errors (i.e. falsely remembering having viewed a script-consistent event that was not actually witnessed). Previous research suggests that backward causal-inference errors are supported by recollection, whereas gap-filling errors are supported by familiarity. We hypothesized that age differences in these errors would parallel the developmental trajectories of these processes. As predicted, age-related increases in backward causal-inference errors were ...

36-month-olds conceal visual and auditory information from others

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

By three years of age, children are skilled at assessing under which circumstances others can see things. However, nothing is known about whether they can use this knowledge to guide their own deceptive behaviour. Here we investigated 3-year-olds' ability to strategically inhibit or conceal forbidden actions that a nearby adult experimenter could see or hear. In the first experiment, children were more likely to disobey the adult when she did not have visual access to their activities than they were when she was looking at them. In the second experiment, in which the adult could never see the child, children refrained from making noise when engaging in a prohibited action that the adult might hear. These results suggest that by three years of age children use their knowledge of others' per...

How do individuals with Williams syndrome learn a route in a real-world environment?

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

This study investigated large-scale route learning in individuals with WS and two matched control groups (moderate learning difficulty group [MLD], typically developing group [TD]). In a non-labelling and a labelling (verbal information provided along the route) condition, participants were guided along one of two unfamiliar 1-km routes with 20 junctions, and then retraced the route themselves (two trials). The WS participants performed less well than the other groups, but given verbal information and repeated experience they learnt nearly all of the turns along the route. The extent of improvement in route knowledge (correct turns) in WS was comparable to that of the control groups. Relational knowledge (correctly identifying spatial relationships between landmarks), compared with the TD ...

The neural basis of speech parsing in children and adults

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

Word segmentation, detecting word boundaries in continuous speech, is a fundamental aspect of language learning that can occur solely by the computation of statistical and speech cues. Fifty-four children underwent functional magnetic resonance imaging (fMRI) while listening to three streams of concatenated syllables that contained either high statistical regularities, high statistical regularities and speech cues, or no easily detectable cues. Significant signal increases over time in temporal cortices suggest that children utilized the cues to implicitly segment the speech streams. This was confirmed by the findings of a second fMRI run, in which children displayed reliably greater activity in the left inferior frontal gyrus when listening to 'words' that had occurred more frequently in ...

Children's attention to sample composition in learning, teaching and discovery

Developmental Science — Mon, 06 Jul 2009 23:00:00 +0100

Two studies compared children's attention to sample composition [ndash] whether a sample provides a diverse representation of a category of interest [ndash] during teacher-led and learner-driven learning contexts. In Study 1 (n = 48), 5-year-olds attended to sample composition to make inferences about biological properties only when samples were presented by a knowledgeable teacher. In contrast, adults attended to sample composition in both teacher-led and learner-driven contexts. In Study 2 (n = 51), 6-year-olds chose to create diverse samples to teach information about biological kinds to another child, but not to discover new information for themselves, whereas adults chose to create diverse samples for both teaching and information discovery. Results suggest that how children approach ...

Dealing with conflicting information: young children's reliance on what they see versus what they are told

Developmental Science — Sat, 04 Jul 2009 23:00:00 +0100

Children often learn about the world through direct observation. However, much of children's knowledge is acquired through the testimony of others. This research investigates how preschoolers weigh these two sources of information when they are in conflict. Children watched as an adult hid a toy in one location. Then the adult told children that the toy was in a different location (i.e. false testimony). When retrieving the toy, 4- and 5-year-olds relied on what they had seen and disregarded the adult's false testimony. However, most 3-year-olds deferred to the false testimony, despite what they had directly observed. Importantly, with a positive searching experience based on what they saw, or with a single prior experience with an adult as unreliable, 3-year-olds subsequently relied on th...

The development of skin conductance fear conditioning in children from ages 3 to 8 years

Developmental Science — Wed, 01 Jul 2009 23:00:00 +0100

Although fear conditioning is an important psychological construct implicated in behavioral and emotional problems, little is known about how it develops in early childhood. Using a differential, partial reinforcement conditioning paradigm, this longitudinal study assessed skin conductance conditioned responses in 200 children at ages 3, 4, 5, 6, and 8 years. Results demonstrated that in both boys and girls: (1) fear conditioning increased across age, particularly from ages 5 to 6 years, (2) the three components of skin conductance fear conditioning that reflect different degrees of automatic and controlled cognitive processes exhibited different developmental profiles, and (3) individual differences in arousal, orienting, and the unconditioned response were associated with individual diff...

Arithmetic word problem solving: a Situation Strategy First framework

Developmental Science — Tue, 30 Jun 2009 23:00:00 +0100

Before instruction, children solve many arithmetic word problems with informal strategies based on the situation described in the problem. A Situation Strategy First framework is introduced that posits that initial representation of the problem activates a situation-based strategy even after instruction: only when it is not efficient for providing the numerical solution is the representation of the problem modified so that the relevant arithmetic knowledge might be used. Three experiments were conducted with Year 3 and Year 4 children. Subtraction, multiplication and division problems were created in two versions involving the same wording but different numerical values. The first version could be mentally solved with a Situation strategy (Si version) and the second with a Mental Arithmeti...

Reduced chromatic discrimination in children with autism spectrum disorders

Developmental Science — Sun, 28 Jun 2009 23:00:00 +0100

Atypical perception in Autism Spectrum Disorders (ASD) is well documented (Dakin & Frith, 2005). However, relatively little is known about colour perception in ASD. Less accurate performance on certain colour tasks has led some to argue that chromatic discrimination is reduced in ASD relative to typical development (Franklin, Sowden, Burley, Notman & Alder, 2008). The current investigation assessed chromatic discrimination in children with high-functioning autism (HFA) and typically developing (TD) children matched on age and non-verbal cognitive ability, using the Farnsworth-Munsell 100 hue test (Experiment 1) and a threshold discrimination task (Experiment 2). In Experiment 1, more errors on the chromatic discrimination task were made by the HFA than the TD group. Comparison with test no...

The role of landmarks and boundaries in the development of spatial memory

Developmental Science — Sun, 28 Jun 2009 23:00:00 +0100

It has been suggested that learning an object's location relative to (1) intramaze landmarks and (2) local boundaries is supported by parallel striatal and hippocampal systems, both of which rely upon input from a third system for orientation. However, little is known about the developmental trajectories of these systems' contributions to spatial learning. The present study tested 5- and 7-year-old children and adults on a water maze-like task in which all three types of cue were available. Participants had to remember the location of an object hidden in a circular bounded environment containing a moveable intramaze landmark and surrounded by distal cues. Children performed less accurately than adults, and showed a different pattern of error. While adults relied most on the stable cue prov...

Evidence for intact memory-guided attention in school-aged children

Developmental Science — Sun, 28 Jun 2009 23:00:00 +0100

Visual scenes contain many statistical regularities such as the likely identity and location of objects that are present; with experience, such regularities can be encoded and can ultimately facilitate the deployment of spatial attention to important locations. Memory-guided attention has been extensively examined in adults with the 'contextual cueing' paradigm and has been linked to specific neural substrates [ndash] a medial temporal lobe (MTL)-frontoparietal network. However, it currently remains unknown when this ability comes 'online' during development. Thus, we examined the performance of school-aged children on an age-appropriate version of the contextual cueing paradigm. Children searched for a target fish among distractor fish in new displays and in 'old' displays on a touchscree...

Two-year-olds compute syntactic structure on-line

Developmental Science — Sun, 28 Jun 2009 23:00:00 +0100

Syntax allows human beings to build an infinite number of new sentences from a finite stock of words. Because toddlers typically utter only one or two words at a time, they have been thought to have no syntax. Using event-related potentials (ERPs), we demonstrated that 2-year-olds do compute syntactic structure when listening to spoken sentences. We observed an early left-lateralized brain response when an expected verb was incorrectly replaced by a noun (or vice versa). Thus, toddlers build on-line expectations as to the syntactic category of the next word in a sentence. In addition, the response topography was different for nouns and verbs, suggesting that different neural networks already underlie noun and verb processing in toddlers, as they do in adults. (Source: Developmental Science...

Young children's use of features to reorient is more than just associative: further evidence against a modular view of spatial processing

Developmental Science — Wed, 24 Jun 2009 23:00:00 +0100

Proponents of a geometric module have argued that instances of young children's use of features as well as geometry to reorient can be explained by a two-stage process. In this model, only the first stage is a true reorientation, accomplished by using geometric information alone; features are considered in a second stage using association (Lee, Shusterman & Spelke, 2006). This account is contradicted by the data from two experiments. Experiment 1a sets the stage for Experiment 1b by showing that young children use geometric information to reorient in a complex geometric figure without a single principal axis of symmetry (an octagon). In such a figure, there are two sets of geometrically congruent corners, with four corners in each set. The addition of a colored wall leads to the existence ...

Superior detection of threat-relevant stimuli in infancy

Developmental Science — Sun, 21 Jun 2009 23:00:00 +0100

The ability to quickly detect potential threat is an important survival mechanism for humans and other animals. Past research has established that adults have an attentional bias for the detection of threat-relevant stimuli, including snakes and spiders as well as angry human faces. Recent studies have documented that preschool children also detect the presence of threatening stimuli more quickly than various non-threatening stimuli. Here we report the first evidence that this attentional bias is present even in infancy. In two experiments, 8- to 14-month-old infants responded more rapidly to snakes than to flowers and more rapidly to angry than to happy faces. These data provide the first evidence of enhanced visual detection of threat-relevant stimuli in infants and hence offer especiall...

Infants' individuation of agents and inert objects

Developmental Science — Sun, 21 Jun 2009 23:00:00 +0100

Using the violation-of-expectancy method, we investigated 10-month-old infants' ability to rely on dynamic features in object individuation processes. Infants were first familiarized to events in which two different objects repeatedly appeared and disappeared, one at a time from behind a screen; at test, the screen was removed, revealing either one or two objects. In Experiment 1, one self-moving non-rigid agent and one inert object were involved in each trial, while in Experiment 2 two different agents were presented. Infants preferred to look at one-object outcomes in Experiment 1, but they did not show any preference for one- or two-object outcomes in Experiment 2. The results suggest that infants can use dynamic information to detect agents in complex individuation tasks before they ca...

Young children follow pointing over words in interpreting acts of reference

Developmental Science — Sun, 21 Jun 2009 23:00:00 +0100

Adults refer young children's attention to things in two basic ways: through the use of pointing (and other deictic gestures) and words (and other linguistic conventions). In the current studies, we referred young children (2- and 4-year-olds) to things in conflicting ways, that is, by pointing to one object while indicating linguistically (in some way) a different object. In Study 1, a novel word was put into competition with a pointing gesture in a mutual exclusivity paradigm; that is, with a known and a novel object in front of the child, the adult pointed to the known object (e.g. a cup) while simultaneously requesting 'the modi'. In contrast to the findings of Jaswal and Hansen (2006), children followed almost exclusively the pointing gesture. In Study 2, when a known word was put int...

Biological components of colour preference in infancy

Developmental Science — Wed, 10 Jun 2009 04:00:00 +0100

Adult colour preference has been summarized quantitatively in terms of weights on the two fundamental neural processes that underlie early colour encoding: the S[minus](L+M) ('blue[ndash]yellow') and L[minus]M ('red[ndash]green') cone-opponent contrast channels (Ling, Hurlbert & Robinson, 2006; Hurlbert & Ling, 2007). Here, we investigate whether colour preference in 4[ndash]5-month-olds may be analysed in the same way. We recorded infants' eye-movements in response to pairwise presentations of eight colour stimuli varying only in hue. Infants looked longest at reddish and shortest at greenish hues. Analyses revealed that the L[minus]M and S[minus](L+M) contrast between stimulus colour and background explained around half of the variation in infant preference across the hue spectrum. Unlik...

The development of spontaneous gender stereotyping in childhood: relations to stereotype knowledge and stereotype flexibility

Developmental Science — Mon, 08 Jun 2009 04:00:00 +0100

The development of spontaneous gender stereotyping in children was investigated using the newly developed Action Interference Paradigm (AIP). This task consists of assigning gender-stereotypical toys as quickly as possible to boys and girls in either a stereotype-congruent or a stereotype-incongruent manner. A pilot study with 38 children (mean age 5.1 years) provided evidence for spontaneous gender stereotyping in the AIP, which was reflected in higher latencies for stereotype-incongruent compared with stereotype-congruent toy assignments. The main study, with 66 children (aged 5, 8 and 11 years), compared the development of spontaneous stereotyping with established measures of stereotype flexibility and stereotype knowledge. Stereotype flexibility showed a strong increase from age 5 to 1...

Intuitions about gravity and solidity in great apes: the tubes task

Developmental Science — Mon, 08 Jun 2009 04:00:00 +0100

We presented 22 apes with three versions of the tubes task, in which an object is dropped down a tube connected to one of three potential hiding places and the subject is required to locate the object. In two versions, apes were confronted with a causal tube that varied in the amount of perceptual information it provided (i.e. presence or absence of acoustic cues). The third version was a non-causal adaptation of the task in which a painted line 'connected' dropping and hiding places. Results indicate that apes neither have a reliable gravity bias when tested with the tubes, nor understand the causal function of the tube. Even though there is evidence that they can integrate tube-related causal information to localize the object, they seem to depend mainly on non-causal inferences when sea...

Better working memory for non-social targets in infant siblings of children with Autism Spectrum Disorder

Developmental Science — Mon, 08 Jun 2009 04:00:00 +0100

We compared working memory (WM) for the location of social versus non-social targets in infant siblings of children with Autism Spectrum Disorders (sibs-ASD, n = 25) and of typically developing children (sibs-TD, n = 30) at 6.5 and 9 months of age. There was a significant interaction of risk group and target type on WM, in which the sibs-ASD had better WM for non-social targets as compared with controls. There was no group by stimulus interaction on two non-memory measures. The results suggest that the increased competency of sibs-ASD in WM (creating, updating and using transient representations) for non-social stimuli distinguishes them from sibs-TD by 9 months of age. This early emerging strength is discussed as a developmental pathway that may have implications for social attention and ...

Sensori-motor experience leads to changes in visual processing in the developing brain

Developmental Science — Mon, 08 Jun 2009 04:00:00 +0100

Since Broca's studies on language processing, cortical functional specialization has been considered to be integral to efficient neural processing. A fundamental question in cognitive neuroscience concerns the type of learning that is required for functional specialization to develop. To address this issue with respect to the development of neural specialization for letters, we used functional magnetic resonance imaging (fMRI) to compare brain activation patterns in pre-school children before and after different letter-learning conditions: a sensori-motor group practised printing letters during the learning phase, while the control group practised visual recognition. Results demonstrated an overall left-hemisphere bias for processing letters in these pre-literate participants, but, more in...

Asymmetrical cortical processing of radial expansion / contraction in infants and adults

Developmental Science — Mon, 08 Jun 2009 04:00:00 +0100

We report asymmetrical cortical responses (steady-state visual evoked potentials) to radial expansion and contraction in human infants and adults. Forty-four infants (22 3-month-olds and 22 4-month-olds) and nine adults viewed dynamic dot patterns which cyclically (2.1 Hz) alternate between radial expansion (or contraction) and random directional motion. The first harmonic (F1) response in the steady-state VEP response must arise from mechanisms sensitive to the global radial motion structure. We compared F1 amplitudes between expansion-random and contraction-random motion alternations. F1 amplitudes for contraction were significantly larger than those for expansion for the older infants and adults but not for the younger infants. These results suggest that the human cortical motion mechan...

Brainstem correlates of temporal auditory processing in children with specific language impairment