Functional neuroanatomy of gesture–speech integration in children varies with individual differences in gesture processing

Gesture is an integral part of children's communicative repertoire. However, little is known about the neurobiology of speech and gesture integration in the developing brain. We investigated how 8‐ to 10‐year‐old children processed gesture that was essential to understanding a set of narratives. We asked whether the functional neuroanatomy of gesture–speech integration varies as a function of (1) the content of speech, and/or (2) individual differences in how gesture is processed. When gestures provided missing information not present in the speech (i.e., disambiguating gesture; e.g., “pet” + flapping palms = bird), the presence of gesture led to increased activity in inferior frontal gyri, the right middle temporal gyrus, and the left superior temporal gyrus, compared to when gesture provided redundant information (i.e., reinforcing gesture; e.g., “bird” + flapping palms = bird). This pattern of activation was found only in children who were able to successfully integrate gesture and speech behaviorally, as indicated by their performance on post‐test story comprehension questions. Children who did not glean meaning from gesture did not show differential activation across the two conditions. Our results suggest that the brain activation pattern for gesture–speech integration in children overlaps with—but is broader than—the pattern in adults performing the same task. Overall, our results provide a possible neurobiological mechanism that could underlie children's increasing ability to integrate gesture and speech over childhood, and account for individual differences in that integration.     

Children's use of gesture to resolve lexical ambiguity

We report on a study investigating 3–5‐year‐old children's use of gesture to resolve lexical ambiguity. Children were told three short stories that contained two homonym senses; for example, bat (flying mammal) and bat (sports equipment). They were then asked to re‐tell these stories to a second experimenter. The data were coded for the means that children used during attempts at disambiguation: speech, gesture, or a combination of the two. The results indicated that the 3‐year‐old children rarely disambiguated the two senses, mainly using deictic pointing gestures during attempts at disambiguation. In contrast, the 4‐year‐old children attempted to disambiguate the two senses more often, using a larger proportion of iconic gestures than the other children. The 5‐year‐old children used less iconic gestures than the 4‐year‐olds, but unlike the 3‐year‐olds, were able to disambiguate the senses through the verbal channel. The results highlight the value of gesture to the development of children's language and communication skills.     

Magical thinking in judgments of causation: Can anomalous phenomena affect ontological causal beliefs in children and adults?

In four experiments, 4‐, 5‐, 6‐ and 9‐year‐old children and adults were tested on the entrenchment of their magical beliefs and their beliefs in the universal power of physical causality. In Experiment 1, even 4‐year‐olds showed some understanding of the difference between ordinary and anomalous (magical) causal events, but only 6‐year‐olds and older participants denied that magic could occur in real life. When shown an anomalous causal event (a transformation of a physical object in an apparently empty box after a magic spell was cast on the box), 4‐ and 6‐year‐olds accepted magical explanations of the event, whereas 9‐year‐olds and adults did not. In Experiment 2, the same patterns of behaviour as above were shown by 6‐ and 9‐year‐olds who demonstrated an understanding of the difference between genuine magical events and similarly looking tricks. Testing the entrenchment of magical beliefs in this experiment showed that 5‐year‐olds tended to retain their magical explanations of the anomalous event, even after the mechanism of the trick had been explained to them, whereas 6‐ and 9‐year‐olds did not. In Experiment 3, adult participants refused to accept magical explanations of the anomalous event and interpreted it as a trick or an illusion, even after this event was repeated 4 times. Yet, when in Experiment 4 similar anomalous causal events were demonstrated without reference to magic, most adults acknowledged, both in their verbal judgments and in their actions, that the anomalous effects were not a fiction but had really occurred. The data of this study suggest that in the modern industrialized world, magical beliefs persist but are disguised to fit the dominant scientific paradigm.     

Developmental changes in automatic rule‐learning mechanisms across early childhood

Infants’ ability to learn complex linguistic regularities from early on has been revealed by electrophysiological studies indicating that 3‐month‐olds, but not adults, can automatically detect non‐adjacent dependencies between syllables. While different ERP responses in adults and infants suggest that both linguistic rule learning and its link to basic auditory processing undergo developmental changes, systematic investigations of the developmental trajectories are scarce. In the present study, we assessed 2‐ and 4‐year‐olds’ ERP indicators of pitch discrimination and linguistic rule learning in a syllable‐based oddball design. To test for the relation between auditory discrimination and rule learning, ERP responses to pitch changes were used as predictor for potential linguistic rule‐learning effects. Results revealed that 2‐year‐olds, but not 4‐year‐olds, showed ERP markers of rule learning. Although, 2‐year‐olds’ rule learning was not dependent on differences in pitch perception, 4‐year‐old children demonstrated a dependency, such that those children who showed more pronounced responses to pitch changes still showed an effect of rule learning. These results narrow down the developmental decline of the ability for automatic linguistic rule learning to the age between 2 and 4 years, and, moreover, point towards a strong modification of this change by auditory processes. At an age when the ability of automatic linguistic rule learning phases out, rule learning can still be observed in children with enhanced auditory responses. The observed interrelations are plausible causes for age‐of‐acquisition effects and inter‐individual differences in language learning.     

Developmental changes in attention: the effects of endogenous cueing and of distractors

We used two reaction time tasks to examine age differences in the ability to use an endogenous cue to shift attention covertly and to ignore distractors. In Experiment 1, 8‐year‐olds, 10‐year‐olds and adults (n = 24 per age) were asked to push a button as soon as they detected a target that was presented in a cued, miscued or non‐cued peripheral location at 100, 400 or 800 ms after the appearance of a central cue. In Experiment 2, 10‐year‐olds and adults (n = 24 per age) were asked to indicate which of two shapes appeared in the periphery 400 ms after a central cue, with those shapes surrounded by compatible or incompatible distractors. Unlike previous studies, the data were corrected for a reaction time bias that can inflate the apparent effect of cueing. Children were slower and more variable than adults overall. However, there were no age differences in the effects of the cues in either experiment: at all ages, the speed of responding was increased similarly by correct cueing and slowed similarly by incorrect cueing. Thus, under these conditions, the ability to use endogenous cues to orient covertly to the periphery is already adult‐like by 8–10 years of age, although there may be subsequent changes in the consistency of responding. In Experiment 2, 10‐year‐olds were slowed more than adults by incompatible distractors. Thus, the ability to ignore distracting information is not adult‐like even by 10 years of age. The findings suggest different rates of development for the ability to shift attention following an endogenous cue and for the ability to filter out irrelevant information.     

Young Mandarin learners use function words to distinguish between nouns and verbs

Mandarin requires neither determiners nor morphological inflections, which casts doubt on Mandarin‐speaking children's ability to use function words as a syntactic bootstrapping tool to identify the form class of a new word. This study examined 3‐ and 5‐year‐old Mandarin learners' ability to use function words to interpret new words as either nouns or verbs in the absence of the requirement for determiners and inflections in the ambient language. In Experiment 1, 3‐, and 5‐year‐old Mandarin‐speaking children were exposed to eight novel words embedded in sentence frames differing only in the form class markers used. The 5‐year‐olds interpreted the novel words as either nouns or verbs depending on the form class markers they heard, while the 3‐year‐olds learned only the nouns. Experiment 2 confirmed that the 5‐year‐olds understood the function of the verb‐marker. Thus, Mandarin‐speaking children can use function words to distinguish nouns versus verbs, and this ability appears between three and five years of age.     

The shift in infant preferences for vowel duration and pitch contour between 6 and 10 months of age

This study investigates the influence of the acoustic properties of vowels on 6‐ and 10‐month‐old infants’ speech preferences. The shape of the contour (bell or monotonic) and the duration (normal or stretched) of vowels were manipulated in words containing the vowels /i/ and /u/, and presented to infants using a two‐choice preference procedure. Experiment 1 examined contour shape: infants heard either normal‐duration bell‐shaped and monotonic contours, or the same two contours with stretched duration. The results show that 6‐month‐olds preferred bell to monotonic contours, whereas 10‐month‐olds preferred monotonic to bell contours. In Experiment 2, infants heard either normal‐duration and stretched bell contours, or normal‐duration and stretched monotonic contours. As in Experiment 1, infants showed age‐specific preferences, with 6‐month‐olds preferring stretched vowels, and 10‐month‐olds preferring normal‐duration vowels. Infants’ attention to the acoustic qualities of vowels, and to speech in general, undergoes a dramatic transformation in the final months of the first year, a transformation that aligns with the emergence of other developmental milestones in speech perception.     

Children show limited movement repertoire when learning a novel motor skill

Examining age differences in motor learning using real‐world tasks is often problematic due to task novelty and biomechanical confounds. Here, we investigated how children and adults acquire a novel motor skill in a virtual environment. Participants of three different age groups (9‐year‐olds, 12‐year‐olds, and adults) learned to use their upper body movements to control a cursor on a computer screen. Results showed that 9‐year‐old and 12‐year‐old children showed poorer ability to control the cursor at the end of practice. Critically, when we investigated the movement coordination, we found that the lower task performance of children was associated with limited exploration of their movement repertoire. These results reveal the critical role of motor exploration in understanding developmental differences in motor learning.     

Attentional distraction and time perception in children

The purpose of the present study was to test the effect of attentional distraction on temporal bisection performance in 5‐ and 8‐year‐old children. During a first learning phase, children were trained to discriminate on a temporal bisection task a short standard duration (2 sec) from a long one (8 sec), presented as visual stimuli. Later, in a second testing phase, intermediate durations (3, 4, 5, 6, 7 s), including the standard durations, were presented. Children's task still was to report if it was a short standard duration or a long one. In addition, during the non‐standard duration, a distracter either did or did not appear. Results showed increasing proportions of “it is the long standard duration” (response “long”) with increasing stimulus durations in both distracter and non‐distracter conditions. However, psychophysical functions were flatter in the 5‐year‐olds than in the 8‐year‐olds, revealing their lower sensibility to time. Nevertheless, the 5‐year‐olds' proportion of long responses was higher under the distracter than in the non‐distracter condition. Consequently, the point of subjective equality (PSE), corresponding to the stimulus duration to which the subject produced 50% of responses of “long” was lower under the distracter condition as compared to the non‐distracter condition. Conversely, for the 8‐year‐olds, the PSE was significantly higher in the distracter than in the non‐distracter condition. Five‐year old children overestimated the time in the presence of an attentional distracter, whereas 8‐year olds tended to underestimate it. The leftward shift and the rightward shift of the PSE in the 5‐ and the 8‐year‐olds, respectively, were accounted for by limited‐capacity attention in the five‐year olds.     

Developmental changes in sensitivity to vocal paralanguage

Developmental changes in children’s sensitivity to the role of acoustic variation in the speech stream in conveying speaker affect (vocal paralanguage) were examined. Four‐, 7‐ and 10‐year‐olds heard utterances in three formats: low‐pass filtered, reiterant, and normal speech. The availability of lexical and paralinguistic information varied across these three formats in a way that required children to base their judgments of speaker affect on different configurations of cues in each format. Across ages, the best performance was obtained when a rich array of acoustic cues was present and when there was no competing lexical information. Four‐year‐olds performed at chance when judgments had to be based solely on speech prosody in the filtered format and they were unable to selectively attend to paralanguage when discrepant lexical cues were present in normal speech. Seven‐year‐olds were significantly more sensitive to the paralinguistic role of speech prosody in filtered speech than were 4‐year‐olds and there was a trend toward greater attention to paralanguage when lexical and paralinguistic cues were inconsistent in normal speech. An integration of the ability to utilize prosodic cues to speaker affect with attention to paralanguage in cases of lexical/paralinguistic discrepancy was observed for 10‐year‐olds. The results are discussed in terms of the development of a perceptual bias emerging out of selective attention to language.     

Children's (and Adults') Production Adjustments to Generic and Particular Listener Needs

Adults design utterances to match listeners' informational needs by making both “generic” adjustments (e.g., mentioning atypical more often than typical information) and “particular” adjustments tailored to their specific interlocutor (e.g., including things that their addressee cannot see). For children, however, relevant evidence is mixed. Three experiments investigated how generic and particular factors affect children's production. In Experiment 1, 4‐ to 5‐year‐old children and adults described typical and atypical instrument events to a silent listener who could either see or not see the events. In later extensions, participants described the same events to either a silent (Experiment 2) or an interactive (Experiment 3) addressee with a specific goal. Both adults and 4‐ to 5‐year‐olds performed generic adjustments but, unlike adults, children made listener‐particular adjustments inconsistently. These and prior findings can be explained by assuming that particular adjustments can be costlier for children to implement compared to generic adjustments.     

Co‐speech gesture as input in verb learning

People gesture a great deal when speaking, and research has shown that listeners can interpret the information contained in gesture. The current research examines whether learners can also use co‐speech gesture to inform language learning. Specifically, we examine whether listeners can use information contained in an iconic gesture to assign meaning to a novel verb form. Two experiments demonstrate that adults and 2‐, 3‐, and 4‐year‐old children can infer the meaning of novel intransitive verbs from gestures when no other source of information is present. The findings support the idea that gesture might be a source of input available to language learners.     

Enculturation to musical pitch structure in young children: evidence from behavioral and electrophysiological methods

Children learn the structure of the music of their culture similarly to how they learn the language to which they are exposed in their daily environment. Furthermore, as with language, children acquire this musical knowledge without formal instruction. Two critical aspects of musical pitch structure in Western tonal music are key membership (understanding which notes belong in a key and which do not) and harmony (understanding which notes combine to form chords and which notes and chords tend to follow others). The early developmental trajectory of the acquisition of this knowledge remains unclear, in part because of the difficulty of testing young children. In two experiments, we investigated 4‐ and 5‐year‐olds' enculturation to Western musical pitch using a novel age‐appropriate and engaging behavioral task (Experiment 1) and electroencephalography (EEG; Experiment 2). In Experiment 1 we found behavioral evidence that 5‐year‐olds were sensitive to key membership but not to harmony, and no evidence that 4‐year‐olds were sensitive to either. However, in Experiment 2 we found neurophysiological evidence that 4‐year‐olds were sensitive to both key membership and harmony. Our results suggest that musical enculturation has a long developmental trajectory, and that children may have some knowledge of key membership and harmony before that knowledge can be expressed through explicit behavioral judgments.     

What makes relational reasoning smart? Revisiting the perceptual‐to‐relational shift in the development of generalization

Development of reasoning is often depicted as involving increasing use of relational similarities and decreasing use of perceptual similarities (‘the perceptual‐to‐relational shift’). We argue that this shift is a special case of a broader developmental trend: increasing sensitivity to the predictive accuracy of different similarity types. To test this hypothesis, we asked participants (3‐, 4‐, 5‐year‐olds and adults) to generalize novel information on two types of problems – offspring problems, where relational matches yield accurate generalizations, and prey problems, where perceptual matches yield accurate generalizations. On offspring problems, we replicated prior findings of increasing relational matches with age. However, we observed decreasing relational matches on prey problems. Provided feedback on their responses, 3‐year‐olds showed the same trend. Findings suggest that the relational shift commonly observed in categorization and analogical reasoning may reflect a general increase in children's sensitivity to cue validity rather than an overall preference to generalize over perceptual similarity.     

The effect of changes in posture and clothing on the development of unfamiliar person recognition

In contrast to face recognition little is known about the development of unfamiliar whole‐person recognition. Various cues in a person's appearance may contribute to recognition performance. An age‐related influence of different features on person recognition performance is possible. Here, we investigated two variable features of person recognition, namely posture and clothing, in 4‐year‐olds, 6‐year‐olds, 8‐year‐olds, 10‐year‐olds and adults. The experimental methodology of a short‐term recognition‐test with an immediate four alternative forced choice (4AFC)‐array was used. Targets were shown for 5 seconds. Experiment 1 clearly indicates that a variation of both posture and clothing decreases performance in all age groups compared to a standard, i.e. a no‐change condition. An interaction age×variation of posture and clothing was not observed. In order to untangle the two aspects of posture and clothing, Experiment 2 varied only posture between encoding and recognition. An age‐effect was shown, but no other significant result occurred. Experiment 3 investigated variation of clothing only, and found main effects of clothing and age. Because there was no interaction between the two factors we infer that a change of clothing impairs all subjects' recognition performance. Children's person recognition performance suffers in a way similar to adults' person recognition performance when clothing is varied. In contrast, changing posture does not necessarily decrease recognition accuracy, neither in children nor in adults. No developmental gains were found for dealing with the transformation of posture and clothing between the encoding and recognition phase. Copyright © 2003 John Wiley & Sons, Ltd.     

Developmental Timescale of Rapid Adaptation to Conflicting Cues in Real‐Time Sentence Processing

Children and adults use established global knowledge to generate real‐time linguistic predictions, but less is known about how listeners generate predictions in circumstances that semantically conflict with long‐standing event knowledge. We explore these issues in adults and 5‐ to 10‐year‐old children using an eye‐tracked sentence comprehension task that tests real‐time activation of unexpected events that had been previously encountered in brief stories. Adults generated predictions for these previously unexpected events based on these discourse cues alone, whereas children overall did not override their established global knowledge to generate expectations for semantically conflicting material; however, they do show an increased ability to integrate discourse cues to generate appropriate predictions for sentential endings. These results indicate that the ability to rapidly integrate and deploy semantically conflicting knowledge has a long developmental trajectory, with adult‐like patterns not emerging until later in childhood.     

Development of Recognition of Face Parts from Unfamiliar Faces

The present study examined developmental changes in the ability to recognize face parts. In Experiment 1, participants were familiarized with whole faces and given a recognition test with old and new eyes, noses, mouths, inner faces, outer faces, or whole faces. Adults were above chance in their recognition of the eye and mouth regions. However, children did not naturally encode and recognize face parts independently of the entire face. In addition, all age groups showed comparable inner and outer face recognition, except for 8‐ to 9‐year‐olds who showed a recognition advantage for outer faces. In Experiment 2, when participants were familiarized with eyes, noses, or mouths and tested with eyes, noses, or mouths, respectively, all ages showed above‐chance recognition of eyes and mouths. Thirteen‐ to 14‐year‐olds were adult‐like in their recognition of the eye region, but mouth recognition continued to develop beyond 14 years of age. Nose recognition was above chance among 13‐ to 14‐year‐olds, but recognition scores remained low even in adulthood. The present findings reveal unique developmental trajectories in the use of isolated facial regions in face recognition and suggest that featural cues (as a class) have a different ontogenetic course relative to holistic and configural cues. Copyright © 2012 John Wiley & Sons, Ltd.     

Duck or rabbit? Reversing ambiguous figures and understanding ambiguous representations

In two studies we investigated 3‐ to 5‐year‐old children’s ability to reverse ambiguous figures and the relation between this ability and the ability to understand multiple representations. Children never reversed before they were informed of the two alternative interpretations of the figures. Even when they were informed of the alternatives and understood that both were possible, 3‐year‐olds and most 4‐year‐olds did not reverse. In contrast, a majority of 5‐year‐olds did reverse. In general, children only reversed if they also passed a standard false belief task. However, there was a closer correlation between reversals and a ‘droodle’ task that involved an understanding of the ambiguity of perceptual representations. These results suggest that the immediate experience of reversal may depend on a more abstract understanding of ambiguous representations.     

3—7岁儿童与成人筷子使用动作模式的比较研究

通过比较3—7岁儿童与成人的筷子使用动作模式类型、特征和使用率,初步探讨了筷子使用动作模式的特点及发展趋势。研究结果表明：(1)儿童与成人中均存在八种筷子使用动作模式,各种模式在手指的分工、配合及完成任务的稳定性、适应性等方面表现出不同的特点,具有不同的效率水平;(2)随年龄的增长,个体筷子使用动作模式日趋转向效率较高的类型,表现为高效模式的使用率从3岁组的3．7％增加到成人组的50％,而低效模式的使用率从59．3％下降到10％。